3 Mineralogy and Geology
VI
Report on the Copper Mines of Lake Superior. By Henry R. Schoolcraft.
To the Hon. John C. Calhoun, Secretary of War.
Vernon (Oneida County, N. Y.), November 6, 1820.
Sir: I have now the honor to submit such observations as have occurred to me, during the recent expedition under GOV. Cass, in relation to the copper mines on Lake Superior; reserving, as the subject of a future communication, the facts I have collected on the mineralogy and geology of the country explored generally.
The first striking change in the mineral aspect of the country north of Lake Huron, is presented near the head of the Island of St. Joseph, in the River St. Mary, where the calcareous strata of secondary rocks are succeeded by a formation of red sandstone, which extends northward to the head of that river at Point Iroquois, producing the falls called the Sault de Ste. Marie, fifteen miles below; and thence stretching northwest, along the whole southern shore of Lake Superior, with the interruptions noted, to Fond du Lac.
This extensive stratum is perforated at various points by upheaved masses of sienitic granite and trap, which appear in elevated points on the margin of the lake at Dead River, Keweena Point, Presque Isle, and the Chegoimagon Mountains. It is overlaid, in other parts, by a stratum of gray or neutral-colored sandstone, of uncommon thickness, which appears in various promontories along the shore, and, at the distance of ninety miles from Point Iroquois, constitutes a lofty perpendicular and caverned wall, upon the water’s edge, called the Pictured Rocks.
So obvious a change in the geological character of the rock strata, in passing from Lake Huron to Lake Superior, prepares the observer to expect a corresponding one in the imbedded minerals and other natural features—an expectation which is realized during the first eighty leagues, in the discovery of various minerals. The first appearances of copper are seen at Keweena Point, two hundred and seventy miles beyond the Sault de Ste. Marie, where the debris and pebbles along the shore of the lake contain native copper disseminated in particles varying in size from a grain of sand to a mass of two pounds’ weight. Many of the detached stones of this Point are also colored green by the carbonate of copper, and the rock strata exhibit traces of the same ore. These indications continue to the River Ontonagon, which has long been noted for the large masses of native copper found upon its banks, and about the contiguous country.
This river is one of the largest of thirty tributaries, mostly small, which flow into the lake between Point Iroquois and Fond du Lac. It originates in a district of mountainous country intermediate between the Mississippi River and lakes Huron and Superior. After running in a northern direction for about one hundred and twenty miles, it enters the latter at the computed distance of fifty miles west of the portage of Keweena, in north latitude 46° 52´ 2´´, according to the observations of Capt. Douglass. It is connected, by portages, with the Monomonee River of Green Bay, and with the Chippewa River of the Mississippi. At its mouth there is a village of Chippewa Indians of sixteen families, who subsist chiefly on the fish taken in the river. Their location, independent of that circumstance, does not appear to unite the ordinary advantages of an Indian village of the region.
A strip of alluvial land of a sandy character extends from the lake up the river three or four leagues, where it is succeeded by hills of a broken, sterile aspect, covered, chiefly, with a growth of pine, hemlock, and spruce. Among these hills, which may be considered as lateral spurs of the Porcupine Mountains, the copper mines, so called, are situated, at the computed distance of thirty-two miles from the lake, and in the centre of a region characterized by its wild, rugged, and forbidding appearance. The large mass of native copper lies on the west bank of the river, at the water’s edge, at the foot of an elevated bank, part of which appears to have slipped into the river, carrying with it the mass of copper, together with detached blocks of sienitic granite, trap-rock, and other species common to the soil at that place.
The copper, which is in a pure and malleable state, lies in connection with serpentine rock, one face of which it almost completely overlays. It is also disseminated in masses and grains throughout the substance of the rock. The surface of the metal, unlike most oxidable metals which have been long exposed to the atmosphere, presents a metallic brilliancy, which is probably attributable to the attrition of the semi-annual floods of the river.
The shape of the rock is very irregular; its greatest length is three feet eight inches; its greatest breadth, three feet four inches, with an average thickness of twelve inches. It may, altogether, contain eleven cubic feet.207 It exceeds, in size, the great mass of native iron found some years ago on the banks of Red River, in Louisiana. I have computed the weight of metallic copper in the rock at twenty-two hundred pounds, which is about one-fifth of the lowest estimate made of it by former visitors. Henry, who visited it in 1766, estimated its weight at five tons. The quantity may, however, have been much diminished since its discovery, and the marks of chisels and axes upon it, with the discovery of broken tools, prove that portions have been cut off and carried away. Notwithstanding this reduction, it may still be considered one of the largest and most remarkable bodies of native copper on the globe, and is, so far as known, only exceeded in weight by a specimen found in a valley in Brazil, weighing twenty-six hundred and sixty-six Portuguese pounds. Viewed as a subject of scientific interest, it presents illustrative proofs of an important character. Its connection with a rock which is foreign to the immediate section of country where it lies,208 indicates a removal from its original bed; while the intimate connection of the metal and matrix, and the complete envelopment of masses of the copper by the rock, point to a common and contemporaneous origin, whether that be referable to volcanic agency or water. This conclusion admits of an obvious application to the beds of serpentine and other magnesian rock found in other parts of the lake.
Several other large masses of native copper have been found, either on this river or within the basin of the lake, at various periods since the country has been known, and taken into different parts of the United States and of Europe. A recent analysis of one of these specimens, at the University of Leyden, proves it to be native copper in a state of uncommon purity, and uncombined with any notable portion of either gold or silver.
A mass of copper, weighing twenty-eight pounds, was discovered on an island in Lake Superior, eighty miles west of the Ontonagon. It was taken to Michilimackinac and disposed of. The War Department was formerly supplied with a specimen from this mass, and the analysis above alluded to is also understood to have been made from a portion of it. A piece weighing twelve pounds was found at Winnebago Lake. Other discoveries of this metal have been made, within the region, at various times and places.
The existence of copper in the region of Lake Superior appears to have been known to the earliest travellers and voyagers.
As early as 1689, the Baron La Hontan, in concluding a description of Lake Superior, adds: “That, upon it, we also find copper mines, the metal of which is so fine and plentiful that there is not a seventh part lost from the ore.”—New Voyages to North America, London, 1703.
In 1721, Charlevoix passed through the lakes on his way to the Gulf of Mexico, and did not allow the mineralogy of the country to escape him.
“Large pieces of copper are found in some places on its banks [Lake Superior], and around some of the islands, which are still the objects of a superstitious worship among the Indians. They look upon them with veneration, as if they were the presents of those gods who dwell under the waters. They collect their smallest fragments, which they carefully preserve, without, however, making any use of them. They say that formerly a huge rock of this metal was to be seen elevated a considerable height above the surface of the water, and, as it has now disappeared, they pretend that the gods have carried it elsewhere; but there is great reason to believe that, in process of time, the waves of the lake have covered it entirely with sand and slime. And it is certain that in several places pretty large quantities of this metal have been discovered without being obliged to dig very deep. During the course of my first voyage to this country, I was acquainted with one of our order (Jesuits) who had been formerly a goldsmith, and who, while he was at the mission of Sault de Ste. Marie used to search for this metal, and made candlesticks, crosses, and censers of it, for this copper is often to be met with almost entirely pure.”—Journal of a Voyage to North America.
In 1766, Captain Carver procured several pieces of native copper on the shores of Lake Superior, or on the Chippewa and St. Croix Rivers, which are noticed in his travels, without much precision, however, as to locality, &c. He did not visit the southern shores of Lake Superior, east of the entrance of the Brulé, or Goddard’s River, but states that virgin copper is found on the Ontonagon. Of the north and northeastern shores, he remarks: “That he observed that many of the small islands were covered with copper ore, which appeared like beds of copperas, of which many tons lay in a small space.”—Three Years’ Travels, &c.
In 1771 (four years before the breaking out of the American Revolution), a considerable body of native copper was dug out of the alluvial earth on the banks of the Ontonagon River by two adventurers, of the names of Henry and Bostwick, and, together with a lump of silver ore of eight pounds’ weight, it was transported to Montreal, and from thence shipped to England, where the silver ore was deposited in the British Museum, after an analysis had been made of a portion of it, by which it was determined to contain 60 per cent. of silver.
These individuals were members of a company which had been formed in England for the purpose of working the copper mines of Lake Superior. The Duke of Gloucester, Sir William Johnson, and other gentlemen of rank were members of this company. They built a vessel at Point aux Pins, six miles above the Sault Ste. Marie, to facilitate their operations on the lake. A considerable sum of money was expended in explorations and digging. Isle Maripeau and the Ontonagon were the principal scenes of their search. They found silver, in a detached form, at Point Iroquois, fifteen miles above the present site of Fort Brady.
“Hence,” observes Henry, “we coasted westward, but found nothing till we reached the Ontonagon, where, besides the detached masses of copper formerly mentioned, we saw much of the same metal imbedded in stone.
“Proposing to ourselves to make a trial on the hill, till we were better able to go to work upon the solid rock, we built a house, and sent to the Sault de Ste. Marie for provisions. At the spot pitched upon for the commencement of our operations, a green-colored water, which tinges iron of a copper color, issued from the hill, and this the miners called a leader. In digging, they found frequent masses of copper, some of which were of three pounds’ weight. Having arranged everything for the accommodation of the miners during the winter, we returned to the Sault.
“Early in the spring of 1772, we sent a boat-load of provisions, but it came back on the 20th day of June, bringing with it, to our surprise, the whole establishment of miners. They reported that, in the course of the winter, they had penetrated forty feet into the face of the hill, but, on the arrival of the thaw, the clay, on which, on account of its stiffness, they had relied, and neglected to secure it by supporters, had fallen in. That, from the detached masses of metal which, to the last, had daily presented themselves, they supposed there might be ultimately reached a body of the same, but could form no conjecture of its distance, except that it was probably so far off as not to be pursued without sinking an air shaft. And, lastly, that the work would require the hands of more men than could be fed in the actual situation of the country.
“Here our operations, in this quarter, ended. The metal was probably within our reach, but, if we had found it, the expense of carrying it to Montreal must have exceeded its marketable value. It was never for the exportation of copper that our company was formed, but always with a view to the silver, which it was hoped the ores, whether of copper or lead, might in sufficient quantity contain.”—Travels and Adventures of Alexander Henry.
[In the summer of 1832, being detained by head winds at the mouth of Miner’s River, on Lake Superior, I observed the names of several persons engraved on the sand rock, but much obliterated by the water’s dashing over the rock. Tradition represents that Henry’s miners were detained there, and that they made explorations of the river, which is named from the circumstance. The stream is a mere brook, coming over the shelving sand rock, which is a part of the precipitous range of the Pictured Rocks.]
Sir A. Mackenzie passed through Lake Superior, on his first voyage of discovery, in 1789. He remarks: “At the River Tennagon (Ontonagon) is found a quantity of virgin copper. The Americans, soon after they got possession of the country, sent an agent thither; and I should not be surprised to hear of their employing people to work the mine. Indeed, it might be well worthy the attention of the British subjects to work the mines on the north coast, though they are not supposed to be so rich as those on the south.”—Voyages from Montreal through the Continent of North America.
It is difficult to conceive what, however, is apparent, from the references of Dr. Franklin to the subject, that the supposed mineral riches of Lake Superior had an important bearing on the discussions for settling the ultimate northern boundary of the United States. The British ambassadors had, it seems, from an old map which is before me, claimed a line through the Straits of Michilimackinac and the Illinois and Mississippi rivers, to the Gulf of Mexico.
The attention of the United States Government appears first to have been turned toward the subject during the administration of President John Adams, when the sudden augmentation of the navy rendered the employment of copper in the equipment of ships an object of moment. A mission was therefore authorized to proceed to Lake Superior, of the success of which, as it has not been communicated to the public, nothing can, with certainty, be stated; but from inquiries which have been made during the recent expedition, it is rendered probable that the actual state of our Indian relations, at the time, arrested the advance of the officer into the region where the most valuable beds of copper were supposed to exist, and that the specimens transmitted to Government were procured through the instrumentality of some friendly Indians, employed for the purpose.
Such are the lights which those who have preceded me in this inquiry have thrown upon the subject, all of which have operated in producing public belief in the existence of extensive copper mines on Lake Superior. Travellers have generally coincided that the southern shore of the lake is most metalliferous, and that the Ontonagon River may be considered as the seat of the principal mines. Mr. Gallatin, in his report on the state of American manufactures in 1810, countenances the prevalent opinion, while it has been reiterated in some of our literary journals, and in the numerous ephemeral publications of the times, until public expectation has been considerably raised in regard to them.
Under these circumstances, the recent expedition under Gov. Cass entered the mouth of the Ontonagon River on the 27th of June, having coasted along the southern shore of the lake from the head of the River St. Mary. We spent four days upon the banks of that stream, in the examination of its mineralogy, during which the principal part of our party was encamped at the mouth of the river. Gov. Cass, accompanied by such persons as were necessary in the exploration, proceeded, in two light canoes, to the large mass of copper which has already been described. We found the river broad, deep, and gentle for a distance, and serpentine in its course; then becoming narrower, with an increased velocity of current, and, before reaching the Copper Rock, full of rapids and difficult of ascent. We left our canoes at a point on the rapids, and proceeded on foot, across a rugged tract of country, around which the river formed an extensive semicircle. We came to the river again at the locality of copper. In the course of this curve the river is separated into two branches of nearly equal size. The copper lies on the right-hand fork, and it is subsequently ascertained that this branch is intercepted by three cataracts, at which the river descends over precipitous cliffs of sandstone. The aggregate fall of water at these cataracts has been estimated at seventy feet.
The channel of the river at the Copper Rock is rapid and shallow, and filled with detached masses of rock, which project above the water. The bed of the river is upon sandstone, similar to that under the Palisades on the Hudson. The waters are reddish, a color which they evidently owe to beds of ferruginous clay. The Copper Rock lies partly in the water. Other details in the geological structure and appearance of the country are interesting; but they do not appear to demand a more particular consideration in this report.
During our continuance upon this stream, we procured from an Indian a separate mass of copper weighing nearly nine pounds; which will be forwarded to the War Department. This specimen is partially enveloped with a crust of green carbonate of copper. Small fragments of quartz and sand adhere to the under side, upon which it would appear to have fallen in a liquid state. Several smaller pieces of this metal were procured during our excursion up the Ontonagon, or along the shores of the lake east of this stream.
It may be added that discoveries of masses of native copper, like those of gold and other metals, are generally considered indicative of the existence of mines in the neighborhood. The practical miner regards them as signs which point to larger bodies of the same metals, in the earth, and he is often determined by discoveries of this nature in the choice of the spot for commencing his labors. The predictions drawn from such evidence are more sanguine in proportion to the extent of the discovery. They are not, however, unerring indications, and appear liable to many exceptions. Metallic masses are sometimes found at great distances from their original repositories; and the latter, on the contrary, sometimes occur in the earth, or imbedded in rock strata, where there have been no great external discoveries.
From all the facts, which I have been able to collect on Lake Superior, and after a full deliberation upon them since my return, I have drawn the following conclusions:—
1. That the diluvial soil along the banks of the Ontonagon River, extending to its source, and embracing the contiguous region, which gives origin to the Monomonee River of Green Bay, and to the Wisconsin, Chippewa, and St. Croix Rivers of the Mississippi, contains very frequent, and several extraordinary masses of native, or metallic copper. But that no body of this metal, which is sufficiently extensive to become the object of profitable mining operations, has yet been found at any particular place. This conclusion is supported by the facts adduced, and, so far as theoretical aids can be relied upon, by an application of those facts to the theories of mining. A further extent of country might have been embraced, along the shores of Lake Superior, but the same remark appears applicable to it.
2. That a more intimate knowledge of the mineralogical resources of the country, may be expected to result in the discovery of valuable ores of copper, in the working of which occasional masses and veins of the native metal, may materially enhance the advantages of mining. This inference is rendered probable by the actual state of discoveries, and by the geological character of the country.
These deductions embrace all I have to submit on the mineral geography of the country, so far as regards the copper mines. Other considerations arise from the facilities which the country may present for mining—its adaptation to the purposes of agriculture—the state and disposition of the Indian tribes, and other topics which a design to commence metallurgical operations would suggest. But I have not considered it incumbent upon me to enter into details upon these subjects. It may, in brief, be remarked that the remote situation of the country does not favor the pursuit of mining. It would require the employment of a military force to protect such operations. For, whatever may be their professions, the Indian tribes of the north possess strong natural jealousies, and in situations so remote, are only to be restrained from an indulgence in malignant passions, by the fear of military chastisement.
In looking upon the southern shore of Lake Superior, the period appears distant, when the advantages flowing from a military post upon that frontier, will be produced by the ordinary progress of our settlements—for it presents but few enticements for the agriculturalist. A considerable portion of the shore is rocky, and its alluvions are, in general, of too sandy and light a character for profitable husbandry. With an elevation of six hundred and forty-one feet above the Atlantic, and drawing its waters from territories situated north of the forty-sixth degree of north latitude, Lake Superior cannot be represented as enjoying a climate favorable to the productions of the vegetable kingdom. Its forest trees are chiefly those of the fir kind, mixed with varieties of the betula, lynn, oak, and maple. Meteorological observations indicate, however, a warm summer, the average observed heat of the month of June being 69. But the climate is subject to a long and severe winter, and to sudden transitions of the summer temperature. We saw no Indian corn among the natives.
A country lacking a fertile soil, may still become a rich mining country, like the county of Cornwall in England, the Hartz Mountains in Germany, and a portion of Missouri, in our own country. But this deficiency must be compensated by the advantages of geographical position, a contiguous or redundant population, partial districts of good land, or a good market. To these, the mineral districts of Lake Superior can advance but a feeble claim, while it lies upwards of three hundred miles beyond the utmost point of our settlements, and in the occupation of savage tribes whose hostility has been so recently manifested.
Concerning the variety, importance, and extent of its latent mineral resources, I think little doubt can remain. Every fact which has been noticed tends to strengthen the belief that future observations will indicate extensive mines upon its shores, and render it an attractive field of mineralogical discovery. In the event of mining operations, the facilities of a ready transportation of the crude ores to the Sault de Ste. Marie, will point out that place as uniting, with a commanding geographical position, superior advantages for the reduction of the ores, and the general facilities of commerce. At this place, a fall of twenty-two feet, in the river, in the distance of half a mile, creates sufficient power to drive hydraulic works to any extent; while the surrounding country is such as to admit of an agricultural settlement.
I accompany this report with a geological sketch of a vertical section of the left bank of the Mississippi at St. Peter’s, embracing a formation of native copper. This formation was first noticed by the officers of the garrison, who directed the quarrying of stone at this spot. The masses of copper found are small, none exceeding a pound in weight.
I have the honor to be, sir,
Very respectfully,
Your obedient servant,
HENRY R. SCHOOLCRAFT.
VII
Observations on the Geology and Mineralogy of the Region embracing the Sources of the Mississippi River, and the Great Lake Basins, during the Expedition of 1820. Illustrated with Geological Profiles, and Numerous Diagrams and Views of Scenery. By Henry R. Schoolcraft, U. S. Geol. and Minera. Exp.
To the Hon. John C. Calhoun, Secretary of War.
Washington, April 2, 1822.
Sir: I have the honor, herewith, to submit the general report of my observations on the geology and mineralogy of the region visited by the recent expedition to the sources of the Mississippi River. I transmitted to the Department on the 6th of November, 1820, a report on the existence of Copper Mines in the Basin of Lake Superior, together with specimens of the native metal, which were politely taken charge of at Albany by General Stephen Van Rensselaer, M. C. Will it be consistent with the views of the Department to print these reports?
I have the honor to be, sir,
Very respectfully,
Your obedient servant,
HENRY R. SCHOOLCRAFT.
REPLY.
War Department, April 6, 1822.
Sir: I have received your interesting report on the geology and mineralogy of that section of the western country embraced by the late expedition of Gov. Cass; and, although I have not had it in my power, as yet, to peruse it with attention, I will see you, at any time you please, on the subject of your letter respecting it.
I am, sir,
Respectfully,
Your obedient servant,
J. C. CALHOUN.
Mr. Henry R. Schoolcraft.
Albany, March, 1822.
Sir: Agreeably to your appointment as a member of the expedition to explore the sources of the Mississippi, by the way of the Lakes, I proceeded to join the party organized for that purpose at Detroit, by His Excellency Lewis Cass. Diurnal notes were kept of the changes in the geological features of the regions visited; of the mineralogy of the country; and of such facts as could be ascertained, with the means at command, to determine its general physical character and value.209
I have heretofore reported to you the facts and appearances which indicate the existence of the ores of copper, and of valuable deposits of copper in its native form, in the basin of Lake Superior—a point which constituted one of the primary objects to which my attention was called—and I now proceed to state such particulars in the topics confided to me as fell within my observation.
In generalizing the facts, it must be observed that the expedition had objects of a practical character relative to the number, disposition, and feelings to be learned respecting the Indian tribes; that the transit over large portions of the country was necessarily rapid; and that few opportunities of elaborate or long-continued observations occurred at any one point. The topography was committed to a gentleman who is every way qualified for that topic, who was well supplied with instruments, and who will do ample justice to that department. I make these remarks to prepare you for a class of observations which are necessarily technical, and quite imperfect, and to which it is felt that it will not be an easy task to impart a high degree of interest, whatever may have been the anticipations.
To prepare the mind to appreciate the account which I give of changes and developments in the physical structure of the country, it may be observed that the American continent has experienced some of the most striking mutations in its structure at and north of the great chain of lakes. That chain is itself rather the evidence of disruptions and upheavals of formations, which give its northern coasts, to some extent, the character of ancient—very ancient—volcanic areas of action. These lakes form—except Erie and Ontario—the general boundaries between the primitive and secondary strata. But, however striking this fact may, at particular localities, appear—such as at the Straits of St. Mary, of which the east and west shores are, geologically, of different construction—yet nothing in the grand phenomena of the whole region visited is so remarkable as the boulder stratum, which is spread, generally, from the north to the south. Some of the blocks of rock are enormous, and would seem to defy any known cause of removal from their parent beds; others are smaller, and have had their angles removed, and far the greater number of these transported boulders are quite smooth and rounded by the force of attrition. This drift stratum has been tossed and scattered from its northern latitudes over the surface of the limestones and sandstones of the south. It is mixed with the diluvial soils, in Michigan and elsewhere; but it is evident that, in its diffusion south, the heavier pieces have settled first, while comparatively minute boulders have been carried over or dropped in the plains and prairies of Ohio, Illinois, and more southerly regions. Nobody, with an eye to geology, can mistake the heavy boulder deposits which mark the southern shores of Huron, and become still more abundant on the St. Mary’s, the shores of Lake Superior, and along the channels of the River St. Louis and the Upper Mississippi.
Lake Superior has been the central theatre of volcanic upheavals; but they must have operated at very remote periods, for there is not only no evidence of existing volcanic fires, but the heavy debris everywhere bespeaks long intervals of quietude, and slow elementary degradation. Some of the upheavals were made after the deposition of the sandstone rocks, which are, as at the foot of the Porcupine Mountains, raised up to stand nearly vertical; while other districts of the granitic rock, as at Granite Point, had been elevated before the deposition of the sandstone rock, which is accurately adjusted to its asperities, and remains quite horizontal.
The granitical series of strata, which is apparent in northern New York in the Kayaderasseras Mountains, and at the Thousand Islands of the St. Lawrence, reappear on the north shores of Huron and Superior, underlie the bed of the latter, and rise up in the rough coast between the Chocolate River and Kewaiwenon, cross the Mississippi at the Petite Roche, above the Falls of St. Anthony, and put out spurs as low down as the source of the Fox, the St. Croix, and the head of the St. Peter’s Rivers.
These glimpses of some of the leading points in the geological structure of the regions visited, will enable you to follow my details more understandingly. These details begin at Detroit. From this place the expedition passed, by water, along the southern shores of Lakes St. Clair, Huron, and Superior, to the Fond du Lac; thence, up the River St. Louis, to the Savanne summit. Thence we proceeded across the portage to Sandy Lake, which has an outlet into the Mississippi, and followed up the latter, through the lesser Lake Winnipek, to the entrance of the Turtle River, in Cass, or upper, Red Cedar Lake, which is laid down by Pike in north latitude 47° 42´ 40´´.210 The state of the water was unfavorable to going higher.
From this point, which formed the terminus of the expedition, we descended the Mississippi, making portages around the Falls of Pekagama and St. Anthony, to Prairie du Chien. An excursion was made by me down the Mississippi to the mineral district of Dubuque. We ascended the Wisconsin, to the portage into the Fox River, and traced the latter down to its entrance into Green Bay. At this point, the expedition separated; a part proceeding north, through the bay, to Michilimackinac, and a part going south, along the west shores of Lake Michigan, to Chicago, the latitude of which is placed by Capt. Douglass in 41° 54´ 06´´. At this place, a further division took place. Dr. Wolcott, having reached his station, remained. Governor Cass proceeded across the peninsula of Michigan to Detroit on horseback, leaving Capt. Douglass and myself to complete the survey of Lake Michigan. We rejoined the northern party detached at Green Bay, under Mr. Trowbridge and Mr. Doty, at Michilimackinac; and, after repassing the southern coast of Lakes Huron and St. Clair, reached Detroit.
Topographically, a very wide expanse of wilderness country had been seen. The entire length of route computed to have been traversed, exceeds four thousand miles, in the course of which we had crossed nineteen portages, over which all the baggage and canoes were conveyed on the shoulders of men. We encountered actual resistance from the Indians at only one point.211 I kept my journals continually before me, and had my pencil in hand every morning as soon as it was light enough to discern objects. I began my geological observations at Detroit.
This ancient city, founded by the French in 1701, stands upon an argillaceous stratum, which is divided, topographically, into an upper and lower bank. Wherever this clay has been examined by digging, it discloses pebbles of various species of rock, denoting it, as far as these extend at least, to be a part of the great drift stratum.
In digging a well near the old Council House, in the northeast part of the city, the top soil appeared to be less than two feet. The workmen then passed through a stratum of blue clay, of eight or ten feet, when they struck a vein of coarse sand, six or eight inches in thickness, through which the water entered profusely. The digging was carried through another bed of blue clay, twenty or twenty-two feet in depth, when the men reached a stratum of fine yellow sand, into which they dug three feet and stopped, having found sufficient water. The whole depth of the well is thirty-three feet. The water is clear and rapid. No vegetable or other remains were found, and but few primitive pebbles.
In another well, situated near the centre of the town, the depth of which is twelve feet, the top soil was found to be two feet and a half; then a bed of gravel, seven feet; a vein of blue clay, eight inches, and the residue a whitish-blue clay, very compact and hard; a copious supply of water having been found. The water is, however, slightly colored, and is of a quality called hard.
In some places, this clay drift yields balls of iron pyrites, which renders the water unpalatable. At what depth the rock would be struck, if the excavation were continued, can only be conjectured. A well has been dug, a short distance below the city, upwards of sixty feet, chiefly through clay and gravel, without reaching the rock; but abraded fragments of granite and hornblende rocks were thrown from the greatest depths.
The bed of the river opposite the city has been stated to consist of limestone rock, but without any proof or much probability. From the fact of its affording a good anchorage to vessels, I am inclined to think that it is wholly composed of clay and gravel.
Detroit Fluviatile Clay.—The argillaceous stratum of Detroit extends along both banks of the river to its head; passes around the shores of Lake St. Clair, and up the River St. Clair to Fort Gratiot—a distance of seventy miles. In this distance there are some moderate elevations and depressions in the surfaces of the soil, but no very striking changes in its general character and composition. The boulder stratum is prominent at Gros Point, at the foot of Lake St. Clair, where the shore exhibited some heavy blocks of granite, and other foreign rock.
St. Clair Flats of Plastic Clay.—At the mouth of the River St. Clair, the current is divided into several channels, and spread over a considerable tract of low ground, which is covered with grasses and aquatic plants. These channels have worn their way through beds of tough blue clay, called the flats, over which there is sometimes not over seven feet eight inches of water in the ship channel. They consequently form an impediment to commerce. The depth is, however, always increased in the spring season, when twelve inches more may be generally relied on. Frequently, during the droughts of summer, a change of wind, and its steady continuance for some time, will allow ships to pass without lighters. The permanent removal of this bar is, however, an object of national importance, which cannot but be felt, as the tonnage of the lakes increases.
Ancient Dune; A Buried Forest.—The principal spot where the lands, in the immediate vicinity of the water, assume any considerable or abrupt elevation, is included between Black River of the St. Clair and Lake Huron. Here the outlet of the lake, which is rapid, washes the base of a ridge, or ancient dune, elevated fifty or sixty feet above the water. Fort Gratiot occupies the upper part of this elevation. The lower part consists of the blue clay stratum, corresponding in character with that found in the wells of Detroit. It is overlaid by a deposit of sand, forming two-thirds of the entire height. This elevation is crowned with a light forest of oak and other species. At the line of junction between the sand and clay, a number of trees are seen to be horizontally imbedded, projecting their roots and trunks in a striking manner above the water. These trees, on inspection, are merely preserved, not petrified. They appear to have been exposed to view, in modern times, by the wearing away of the bank. Certainly, none of the old travellers mention them.
The mode of this formation may be clearly seen. Winds, at some ancient period, have been the agent of blowing the sands, as they were washed up by the lake, and redepositing them on part of a prostrated forest, resting directly on the clay stratum. The trees, thus buried in dry sand, have been preserved. In process of time, the river encroached upon these antique beds, exposing them to view. There are also antique fresh-water shells found in similar positions near this spot. No rock is, thus far, found in sitû in ascending the lakes. The old surface of the country is wholly of diluvial formation, except where it shows lake action.
Huron Coast from Fort Gratiot to Michilimackinac.—About two hundred and thirty miles lie stretched out between these two points. Lake Huron charms the eye, with the view of its freshness and oceanic expanse. But the entrance is without rock scenery, and the student of its geology must be a patient gleaner along its shores. Long coasts of sand and gravel extend before the eye, and they are surmounted, at a moderate elevation, with a dense foliage, which limits the view of its structure to a narrow line. Portions of this coast are heavily loaded with the primitive debris212 from the North. These are found, in some places, in heavy masses, but all are more or less abraded, showing that they have been transported from their original beds. In one of these, I observed crystals of staurotide.
The first section of this coast reaches from Fort Gratiot to Point aux Barques, a distance of about seventy-five miles. Nearly midway lies the White Rock, a very large boulder of whitish-gray semi-crystalline limestone, lying off the shore about half a mile, in water of about one and a half fathom’s depth. It is the effect of gulls lighting upon this rock, and not the intensity of the color of the stone, that has originated the name—which is a translation of the Roche Blanche of the older voyageurs. The Detroit clay-formation still characterizes the coast.
First Emergence of Rock, in place, above the Surface.—We are passing, in this section, along and near to the outcrop of the secondary strata of the peninsula, but these strata are covered with a heavy deposit of diluvial clays, sands, and pebble drift. The first emergence of fixed rocks, above the line of the drift, occurs after passing Elm Creek in the advance to Ship Point (Pointe aux Barques). It is a species of coarse gray, loosely compacted sandstone, in horizontal layers. This rock continues to characterize the coast to and around the Ship Point promontory into Saganaw Bay. It possesses a few fossil remains of corallines; but the rock is not of sufficient compactness and durability for architectural purposes. It is conjectured to be one of the outlying series of the coal measures, of which this coast exhibits, further on, other evidences.
Saganaw Bay.—The phenomena of this large body of water, which is some sixty miles long, appear to indicate an original rent in the stratification, having its centre of action very deep. If the peninsula of Michigan be likened to a huge fish’s head, this bay may be considered as its open mouth. We crossed the inner bay from Point aux Chenes, where it is estimated to be twenty miles across.213 The traverse is broken by an island, to which the Indians, with us, applied the name of Sha-wan-gunk.214 It is composed of a dark-colored limestone, of dull and earthy fracture and compact structure. It presents broken and denuded edges at the water level. I observed in it nodular masses of chalcedony and calc. spar. The margin of the island bears fragments of the boulder stratum.
Highlands of Sauble.—On crossing the bay, these highlands present themselves to view in the distance. They are the north-eastern verge of the most elevated central strata of the peninsula. Their structure can only be inferred from the formations along the margin of the lake, extending by Thunder Bay and Presque Isle, and the Isles of Bois Blanc and Round Island to Michilimackinac. At Thunder Bay, the compact limestone of the Saganaw Islands reappears, and is constantly in sight from this point to Presque Isle. It exists in connection with bituminous shale, at an island in Thunder Bay. It is of a dark carbonaceous character on the main opposite Middle Island, at a point which is called by the Indians Sho-sho-ná-bi-kó-king, or Place of the Smooth Rock. I noticed at this point the cyathophyllum helianthoides in abundance, and easily detached them from the rock. The more compact portions of this formation in the approach to Presque Isle, disclosed the ammonite, two species of the gorgonia, and the fragment of a species of chambered shell, whose character is indeterminate.
Much of the coast was footed, as the winds were adverse, and its debris thus subjected to a careful scrutiny. Wherever the limestone was broken up or receded from the water, long lines of yellow beach-sand and lake-gravel, including members of the erratic block stratum, intervened. In some localities, local beds of iron sand occur.
Michilimackinac.215—The approach to this island was screened from our view by the woody shores and forests of Bois Blanc, an island of some twelve miles in length lying off the main land; and the view of it first burst upon us in the narrow channel between it and Round Island. It is a striking geological monument of mutations. Here the calcareous rock, which had before exhibited itself in low ledges along the shore is piled up in masses, which reach an extreme altitude of three hundred and twelve feet. About two hundred feet of this elevation is precipitous on its south, east, and west edge. A hundred feet or more is piled up on its centre, part rock and part soil, in a crowning shape. The highest part of this apex, which is surmounted by the ruins of Fort Holmes, consists of the drift stratum, among which are boulders of sienite, and other foreign rocks. A locality of these abraded boulder-rocks, near the Dousman farm, is worthy of a visit from all who take an interest in the phenomena of boulders dispersed over the continent. The fishermen represent the water around this island to be eighty fathoms in depth. Yet, across these waters, to the utmost altitude of the island, these blocks of foreign rock have been transported. No force capable of effecting this is now known. And the argument of their having been transported on cakes of ice, in the nascent periods of the globe, is rendered stronger by these appearances than any geological proofs which I have yet seen.
Distinctive Character of the Mackinac Limestone.—Nothing appears so completely to puzzle the observer as the first glance at this rock. It is different in appearance from the calcareous rocks, to which my attention has heretofore been called in Western New York, and in Missouri and Illinois. The difficulty is to find a point of comparison. I walked entirely around the island, partly in water, the northern shores being comparatively low. There appeared to be three layers. The first, which rises up from the depths of the lake, scarcely, if at all, reaches the water level. Upon this is superimposed a vesicular rock, of which the vesicles are filled with carbonate of lime in the state of agaric mineral. By exposure to the air, this substance readily decomposes, and assumes an almost limey whiteness, and sometimes a complete pulverulent state. The reticular, or vesicular lines, by which the mass is held together, are thus weakened, and large masses of the craggy parts fall, and assume the condition of debris at the water’s edge. Some conditions of the reticulated filaments are covered with minute crystals of cal. spar; others of minutely crystallized quartz. There appear, at other localities, in low positions, layers of quartz in the condition of a coarse bluish, flinty, striped agate. The entire stratum appears to be a reproduced mass, which is plainly denoted, if I mistake not, by some imbedded masses of an elder lime-rock. The whole stratum is too shelly and fissured to be of value for economical purposes. It yields neither quicklime nor building stone.
Fort Mackinac is erected on the summit of this stratum. The two objects of curiosity, called the Arched Rock, and the point called Robinson’s Folly, are evidences of this tendency of the cliffs to disintegration. The superior stratum which constitutes the nucleus of the Fort Holmes’ summit, contains more silex, diffused throughout its structure. It is, however, of a loose, though hard and shelly character; and has, in the geological mutations of the island been chiefly demolished and washed away. The monumental mass of this period of demolition, called the Sugar Loaf, is a proof that it contained, either by its shape, or otherwise, a superior power of resisting these means of ancient prostration. Striking as it now appears, this is the simple story which it tells. Its apex is probably level, or nearly so, with the Fort Holmes’s summit. Over the whole island, after these demolitions, the drift stratum was deposited.
The German geognosts apply the term mushelkalk, to this species of calcareous rock. It is, apparently, the magnesian limestone of English writers.
Ancient Water Lines.—Such marks appear on the most compact parts of the cliffs, denoting the water to have stood, during the ancient boundaries of the lake, at higher levels.
Lake Action.—It is known that strong currents set into the Straits of Michilimackinac, and out of it, from Lake Michigan, at this point. The fishermen, who set their nets at four hundred feet in the waters, often bring up, entangled in their nets, large compact masses of limestone, which have been fretted into a kind of lacework, by the rotatory motion of little pebbles and grains of sand, kept in perpetual motion by the water at the bottom of the lake.
Organic Impressions.—There are cast up among the lake debris of this island, casts of some species of orthocaratites, ammonites, and madrepores, which appear to be derived from the calcareous rocks in place in the basin of Lake Huron. But the rock strata of the island itself appear to be singularly destitute of these remains. The only species which I have noticed, is one that was thrown up from a well attempted to be dug, on the apex of Fort Holmes, by the British troops, while they held possession of the island in 1813, 1814, and 1815. But this is uniformly fragmentary. It has the precise appearance of the head of a trilobite, but never reveals the whole of the lateral lobes, nor any of the essential connecting parts. It is silicious.
Gyseus Formation.—Evidences of the extension of this formation to this vicinity were brought to my notice; in consequence of which I visited the St. Martin’s Islands, which belong to the Mackinac group. Masses of gypsum were found imbedded in the soil, both of the fibrous and compact variety. These islands are low diluvial formations. Similar masses are found on Goose Island; and the mineral has been found at Point St. Ignace on the main land.
Taken in connection with the discovery of this mineral, at a subsequent part of the journey on Grand River, the indications of the series of the saline group of rocks, so prevalent in the Mississippi Valley, are quite clear up to this extreme point, which is, however, very near the northern verge of this group.
Honeycombed Rocks.—As evidences of existing lake action, it has already been mentioned that the fishermen bring up, from great depths in the straits, pieces of compact limestone, completely fretted and excavated by small pebbles, which are kept in motion by the strong currents which prevail at profound depths. The process of their formation by these currents is such, as in some instances to give the appearance of cellepores, and analogous forms of organic life. I have seen nothing in these carious forms which does not reveal the mechanical action of these waters.
Pseudomorphic Forms.—Amongst the limestone debris, of recent date, found on these shores, are pieces of rock which have an appearance as if they had been punctured with a lancet, or blade of a penknife. These incisions are numerous, and from their regularity, appear to have been moulded on some crystals which have subsequently decayed. Yet, there are difficulties in supposing such to have been the origin of these small angular orifices.
Whenever these masses are examined by obtaining a fresh fracture, they are found to consist of the compact gray and semi-granular rock of the inferior Mackinac group, but in no instance of the vesicular or silicious varieties. These blocks appear to be identical in character with the White Rock, before noticed.
North Shore of Lake Huron.—The next portion of the country examined was that of the north shores of the lake, extending from Michilimackinac to Point Detour, the west Cape of the Straits of St. Mary’s, a distance computed to be forty miles. The calcareous rock, such as it appears in the inferior stratum of Mackinac, extends along this coast. The first three leagues of it, consist of an open traverse across an arm of the lake. Goose Island offers a shelter to the voyager, which is generally embraced. It consists of an accumulation of pebbles and boulders on a reef, with a light soil, resting on the lower limestone. It does not, perhaps, at any point, rise to an elevation of more than eight or ten feet above the water. Outard Point, a short league, or rather three miles further, exhibits the same underlying formation of rock, which is found wherever solid points put out into the lake, during the entire distance. The chain of islands called Chenos, extends about twenty miles, and affords shelter during storms to boatmen and canoemen, who are compelled to pass this coast. Large masses of the rock, with its angles quite entire, lie along parts of the shore, and appear to have been but recently detached. The intervals between these blocks and points of coast, are formed of the loose sand and pebbles of the lake, which are more or less affected by every tempest. The only organic remains and impressions are drift-specimens, which have been driven about by the waves, and are abraded. Broken valves of the anadonta, occasionally found in similar positions, denote that this species exists in the region, but that the outer localities of the coast are entirely unfavorable to their growth.
Drummond Island.—This island, now in the possession of British troops, who removed from Michilimackinac in 1816, is the western terminus of the Manatouline chain. We did not visit it, but learn from authentic sources, that it is a continuation of the nether Mackinac limestone—and that the locality abounds in loose petrifactions, which appear to have belonged to an upper stratum of the rock, now disrupted.216
Straits of St. Mary’s.—These straits, and the river which falls into their head, connect Lakes Huron and Superior. They appear to occupy the ancient line of junction between the great calcareous and granitic series of rocks on the continent. The limestone, which has been noticed along the north shore of the Huron from Michilimackinac, and which continues, with interruptions of water only, from Detour to Drummond Island, and the Manatoulines, is to be noticed up the straits as high as Isle a la Crosse, where the last locality of a pure carbonate of lime appears to occur. The island of St. Joseph is chiefly primitive rock, and its south end is heavily loaded with granitic, porphyritic, and quartz boulders. The north shores of the river, opposite and above this island, are entirely of the granitic series, which continues to Gros Cape of Lake Superior. On reaching the Nebeesh,217 or Sailor’s Encampment Island, sandstone rocks of a red color present themselves, and are found also on the American side of the river, and continue to characterize it to the Falls, or Sault de Ste. Marie,218 and to Point Iroquois and Isle Parisien in Lake Superior.
The Sault of St. Mary’s is upon and over this red sandstone. The river makes several successive leaps, of a few feet at a time, in its central channel, falling, altogether, about twenty-two feet in half a mile. This gives it a foaming appearance, and the volume pours a heavy murmur on the ear.219 It is, of course, a complete interruption to the navigation of vessels, which can, however, come to anchor near its foot, while barges may be pushed up, empty, on the American shore. The water-power created by such a change of level, is such as must commend the spot, at a future period, to manufacturers, lumbermen, and miners. The foot of these falls is heavily incumbered, both with masses of the disrupted sand-rock220 and granitic and conglomerate boulders.
Red Sandstone of Lake Superior.—That this is the old red sandstone, may be inferred simply from the fact that, although deposited originally in horizontal beds, its position has been disturbed in many localities.
Plastic Clay Stratum of the Lakes.—The northern extremity of Muddy Lake—a sheet of water some twenty miles in length—is the head of the straits, and the beginning of the River St. Mary’s. This sheet of water has the property of being rendered slightly whitish, or turbid, by continuous winds. Its bottom appears to be formed of the same plastic blue clay which obstructs the passage of vessels of large draft on the St. Clair flats, and forms an impediment of a similar kind in this river in Lake George. This stratum seems to be the result of causes not now in operation. If dredged through, or excavated, there is no reason to suppose it would again accumulate; for the waters of the lake are clear and pure, and carry down no deposit of the kind. These clay deposits remain to attest physical changes which are past. They denote the demolition of formations of slate in the upper regions, which have been broken down and washed away when the dominion of the waters was far more potential than they now are.
This formation is favorable to the growth of some species of fresh-water shells. I observed several species of the anadonta and the plenorbis, and think, from the broken valves, that research would develop others.
Porphyry and Conglomerate Boulders.—A formation of red jasper, in common white quartz, exists, in the bed of intersection, on the southeastern foot of Sugar Island. The fragments of jasper are of a bright vermil red, quite opaque, and have preserved their angles. I had observed fragments of the formation along the shores of the lower part of the straits, and even picked up some specimens, entirely abraded, however, on the south shores of the Huron, between the White Rock and Michilimackinac—a proof of the course of the drift.
The granitic conglomerates appear quite conclusive, one would think, of the results of fusion. The attraction of aggregation would seem inadequate to hold together such diverse masses. In these curious and striking masses we see the red feldspathic granite, black and shining hornblende rock, white fatty quartz, and striped jasper, held together as firmly, and polished by attrition as completely, as if they were—what they are not—the results of crystallization in this aggregate form.
Erratic Block Group.—Wherever, in fact, the geologist sets his foot, on the shores of the upper lakes, he finds himself on the great drift stratum, and cannot but revert to that era when waters, on a grander scale, swept over these plains, and the lakes played rampantly over wider areas.221
Basin of Lake Superior.—We entered this island sea as if by a kind of geological gate, in which the sandstone cliffs of Point Iroquois, on the one hand, stand opposite to the granitical hills of Gross Cape on the other.
In order to conceive of its geology, it may subserve the purposes of description to compare it to a vast basonic crater. The rim of this crater has been estimated, by Sir Alexander Mackenzie, at fifteen hundred miles. The primitive formations of Labrador and Hudson’s Bay coasts come up, so as to form the eastern and northern sides of the rim, around which they stand in cliffs of sienitic greenstone and hornblendic rocks, in some places a thousand feet high. On its south and southwest shores, this formation of the elder class of rocks forms also a considerable portion of the coast; as in the rough tract of Granite Point, the Porcupine and Iron River Mountains, and the primitive tract west of Chegoimegon, or Lapointe. It will serve to denote the broken character of this rim, if we state that the entire plain of the lake, running against and fitting to this rim, was originally filled up with the red, gray, and mottled sandstone, which gave way and fell in at localities west of the great Keweena Peninsula, converting its bottom into an anteclinal axis.
Volcanic action, to which this disturbance in its westerly bearings may be attributed, appears to have thrown up the trap-rocks of the Pic, of the Porcupine chain, of the Isle Royal group, and other trap islands, and the long peninsula of Keweena. This system of forces appears to have spent itself from the northeast to the southwest. The shocks brought with them the elements of the copper and other metallic bodies which characterize the trap-rock. They exhausted their power, on the American side, west of the granitic tract of Chocolate and Dead Rivers, and the Totosh and Cradle-Top Mountains. The most violent disturbance took place at the west of the Keweena Peninsula, and thence it was propagated in the direction of the higher Ontonagon, the Iron, and the Montreal rivers.
This disturbance of the level of the sandstone produced undulations, which are observable on the St. Mary’s, where the variation from a level is not more than eight or ten degrees. They left portions of it—as between Isle au Train and the Firesteel River—undisturbed; and they threw other portions of it—as between Iron and Montreal rivers—almost completely on their edges.
The entire north shore from Gargontwa to the old Grand Portage, inclusive of the Michepicotin and Pic regions, cannot be particularly alluded to, as that part of the coast was not visited; but the accounts of observers represent it as consisting of trap-rocks. Without the application of such forces, it appears impossible to understand the geology of this lake, or to account for the sectional and disturbed formations.
The lake itself, whose depth is great, and which has an extreme length of about 500 miles, by an extreme width of some 180, is endowed with powerful means of existing elemental action. This consists almost entirely of the force of its winds and long, sweeping waves. Its bottom may, in this light, be looked upon as an immense mortar or triturating apparatus, in which its sandstones, trap-boulders, and pebbles are driven about and comminuted. This power has greatly changed its configuration, and the process of these mutations is daily going on.
It is only by such a power of geological action that we can account for the powerful demolitions and inroads which it has made upon some parts of its southern borders. The coasts of the Pictured Rocks, which have a prominent development of about 12 to 15 miles, consist in horizontal strata of coarse gray sandstone, of little cohering power. The effect of waves beating upon rocks is to communicate a curved line. This has operated to excavate numerous and extensive caves into the coast. These, after reaching hundreds of feet, have in some cases united. The effect is to isolate portions of the coast, and to leave it in fearful pinnacles, having many of the architectural characters of Gothic or Doric ruins.
The portion of coast immediately west of Grand Marrais is scarcely less unique. It denotes the effect of the prostrating power of the lake in another way. The sandstone of parts of the coast, ground down into yellow sand by this vast machinery, is lifted up by the winds as soon as it reaches the point of dryness, and heaped up into vast dunes. Standing trees are buried in these tempests of sand, and its effect is, for about nine miles along the coast, to present, at an elevation of several hundred feet, a scene of arid desolation, which can only be equalled by the Arabic deserts.
A dyke of trap seems once to have extended from the north shore to Point Keweena; but, if so, it has been prostrated, and its contents—veins and deposits, silicious and metallic—scattered profusely around the shores of the lakes. A cause less general is hardly sufficient to account for the wide distribution of fragments of the copper veins and vein-stones which have so long been noticed as characters of this lake. The basal remains of this antique dyke form the peninsula of Keweena. The tempests beating against this barrier from the northwest, have ripped up terrific areas from the solid rock, and left its covering, amygdaloid and rubblestones, in fantastic patches upon the more solid parts, or constituting islands in front of them.
Structure of its Southern Coast.—The estimated distance from Sault Ste. Marie to Fond du Lac is a fraction over 500 miles. The sandstone, as it appears in the Falls of the St. Mary’s, does not appear to be entirely level. It exhibits an undulation of about 8° or 10°, dipping to west-northwest. Two instances of this waved stratification of the Lake Superior sandstone deserve notice. The first terminates at the intersection of red sand rock at la Point des Grande Sables with the beginning of the horizontal strata of the Pictured Rocks. We again observe an inclination of the strata of a few degrees at Grand Island, which is moreingfish River, and appears to dip at Isle aux Trains, about twenty miles northeast. The scenery is peculiarly soft and pleasing in passing the Huron Islands, a granitic group, and directing the view, as in the sketch, to the coast and the rough granitical hills rising behind Huron Bay. The strata are level, as shown above, around the Bay of Presque Isle and Granite Point, and continue so, resting on the roots of the granitical tract of the Tötosh, or Schoolcraft, and Cradletop Mountains, and at Point aux Beignes, and Keweena Bay. This level position of the rock is preserved to the south cape of the shallow bay of the Bete Gre, on the north, at which the trap-dykes of the peninsula first begin; and so continues after passing that rugged coast of the vitreous series of that remarkable point, to and beyond Eagle River and Sandy Bay, in the approach to the portage of the Keweena.
The same horizontality is observed on the headland west of it, and upon all the points and headlands to Misery and Firesteel Rivers and the mouth of the Ontonagon. The trap-dyke of Keweena crosses this river about ten miles, in a direct line, inland.
At Iron River, we observe a stratum of compact gray grauwacke, over the hackly bed of which that river forces its way during the spring months, and stands in tanks and pools during the summer. On reaching the foot of the Porcupine Mountains, the sandstone, which is here of a dark chocolate color, with quartz pebbles of the bigness of a pigeon’s egg, and organic remains of paleozoic type, is found to be tilted up into nearly a vertical position, as shown in the sketch. The grauwacke reappears, in a most striking manner, at the Falls of Presque Isle River, where the whole mass of water precipitated from the highlands drops into a vast pot-hole, a hundred feet wide and perhaps twice that depth. The whole upper series of rocks, from the Porcupine Cliffs west to the Montreal River, is a conglomerate. At the Falls of the Montreal, the river drops over the vertical edges of the red sandstone. Beyond the Bay of St. Chares, at Lapointe Chegoimigon, masses of sienitic mountains arise, which have their apex near La Riviere de Fromboise.
The Islands of the Twelve Apostles, or Federation Group, appear to be all based on the sienitic or trap, with overlying red sandstone; which latter again reappears on the point of the entrance into Fond du Lac Bay, and marks its southern coast, till near the entrance of the Brulé, or Misakoda River, as seen in the illustration beneath. Shores of sand then intercept its view to the entrance of the River St. Louis, and up its channel to its first rapids, about eighteen miles, where the red sandstone again appears, as the first series of the Cabotian Mountains.
Serpentine Rock.—At the nearest point north of Rivier du Mort is a headland of this rock, jutting out from the granitical formation. Lapping against it, at the mouth of the river, is a curious formation of magnesian breccia. The serpentine rock appears, in nearly every locality examined, to be highly charged with particles of chromate of iron. It may be expected to yield the usual magnesian minerals.222 Its position is between the Carp River and Granite Point, in the Bay of Presque Isle, or rather Chocolate River, for that river pours into this bay by far the largest quantity of water.223
Ancient Drift-Stratum.—In the intervals between the points and headlands, where the rock formation is exposed by streams or gorges, the drift, or erratic boulder stratum, is found. Such is its position beneath the sand-dunes of the Grandes Sables, and in the elder plains and uplands, stretching with interruptions on the coast from the head of the Mary’s valley to that of the St. Louis. The edge of this formation is composed of the sand and loose pebbles and boulders of the lake. Mighty as are the existing causes of action of the lake in beating down and disrupting strata of every kind, and in reproducing alluvial lands and dunes, they are weak and local when compared to the causes which have spread these ponderous boulders, and drift masses over latitudes and longitudes which appear to be limited only by the leading elevations of the continent. That oceanic torrents of water, suddenly heaped on the land, and wedged into compactness and power now unknown to it, is after all, the most plausible theory of the dispersion of this formation, and this theory avoids the necessary local one of the glacial dispersion which presupposes a very low temperature over the whole surface of the globe.
Kaugwudju.224—This imposing mass of the trap-rocks is the highest on the southern shores of Lake Superior. The following outlines of it are taken from a point on the approach to the Ontonagon River, about forty miles distant.
They rise to their apex about thirty miles west of that stream, in north lat. 46° 52´ 2´´, as observed by Captain Douglass. They are distant three hundred and fifty miles from St. Mary’s. In a serene day they present a lofty outline, and were seen by us from the east, at the distance of about eighty miles. The Indians represent them to have a deep tarn, with very imposing perpendicular walls, at one of the highest points. If Lake Superior be estimated at six hundred and forty feet above the Atlantic, as my notes indicate, its peaks are higher than any estimates we have of the source of the Mississippi, and are, at least, the highest elevations on this part of the continent. The granitical tract of the St. Francis, Missouri,225 and of the quartz high lands of Wachita, Arkansas, the only two known primitive elevations between the Rocky and Alleghany chains, are far less elevated.
I have now taken a rapid glance at the formations along the southern shore of the lake between St. Mary’s and Fond du Lac; but have passed by some features which may be thought to merit attention.
Existing Lake Drift.—The gleaner among the rock debris of this lake has a field of labor which is not dissimilar to that of the fossilist. If he has not, so to say, to put joint to joint, to establish his conclusions, he has a mineralogical adjustment to make every way as obscure. A boulder of sienite, or a mass of sandstone, or grauwacke, may be easily referred to a contiguous rock. But when the observer meets with species which are apparently foreign to the region, he is placed in a dilemma between the toil of an impossible scrutiny and the danger of an unlicensed conjecture.
Among the more common masses which may be assigned a locality within the compass of the lake, are granites, sienites, hornblendes, greenstones, schists, traps, grauwackes, sandstones, porphyries, quartz rocks, serpentines, breccias, amygdaloids, amphiboles, and a variety of masses in which epidote and hornblende are essential constituents. With these, the coast mineralogist must associate, in place or out of place, agates, chalcedonies, carnelians, zeolite, prehnite, calcareous spar, crystalline quartz, amethystine quartz, coarse jaspers, noble serpentine, iron-sand, iron-glance, sulphate of lead, chromate of iron, native copper, carbonate of copper, and various species of pyrites. These were, at least, my principal rewards for about eighteen days’ labor, in scrutinizing, at every possible point, its lengthened and varied coasts.
Cupreous Formation.—The whole region, above Grand Island at least, appears to have been the theatre of trap-dykes, and an extensive action from beneath, which brought to the surface the elements of the formation of copper veins. These have not been much explored; but, so far as observation goes, there are evidences which cannot be resisted, that the region contains this metal in various shapes and great abundance. I refer to my report of the 6th of November, 1820, for evidences of a valuable deposit of this metal in the valley of the Ontonagon River, and at other points. I found the metal in its native state at various other localities, and always under physical evidences which denoted its existence, in the geological column of the lake, in quantity. These indications were confined almost exclusively to the area intervening between the peninsula of Keweena, and La Pointe Chegoimegon, a distance of about one hundred and fifty miles. Of this district, the two extremities would make the Ontonagon Valley about the centre.226 A profile of one of the detached pieces, found in the Ontonagon Valley, and forwarded to you by Mr. Van Rensselaer, is herewith given.
Vitric Boulders.—Among the debris of Lake Superior are masses of trachyte, and also small pieces of the sienitic series, in which the red feldspar has a calcined appearance, the quartz being, at the same time, converted into a perfectly vitreous texture. Similar productions, but not of the same exact character, exist on the sandy summits of the Grande Sable. These exhibit an exterior of glistening cells or orifices: it may be possible that they have been produced by fusion; but I think not. The smooth cells appear like grains of sand hurled by the winds over these bleak dunes. I have brought from that locality a single specimen of pitchstone, perfectly resinous, bleak and shining.
La Pointe Chegoimegon.—A sketch of these islands, as given in the Narrative, denotes that their number is greatly underrated, and will serve to show the configuration of a very marked part of the Superior coast. It must, hereafter, become one of the principal harbors and anchoring-ground for vessels of the lake.
Valley of the St. Louis River.—The St. Louis River takes its rise on the southern side of the Hauteur des Terres, being the same formation of the drift and erratic block stratum which gives origin, at a more westerly point, to the Mississippi. Its tributaries lie northwest of the Rainy Lakes. Vermilion Lake, a well-known point of Indian trade, is a tributary to its volume, which is large, and its outlet rushes with a great impetus to the lake. At what height its sources lie above Lake Superior, we can only conjecture. It was estimated to have a fall of two hundred and nine feet to the head of the Portage aux Coteaux, and may have a similar rise above.
By far its most distinguishing feature is its passage at the Grand Portage through the Cabotian Mountains. We entered it at Fond du Lac and pursued up its channel through alluvial grounds, in which it winds with a deep channel about nineteen or twenty miles to the foot of its first rapids. This point was found one mile above the station of the American Fur Company’s trading-house. Here we encountered the first rock stratum, in the shape of our old geological acquaintance, the old red sandstone of Lake Superior. It was succeeded in the first sixteen miles, in the course of which the river is estimated to fall two hundred feet—most of it in the first twenty-nine miles—by trap, argillite, and grauwacke. Through these barriers the water forces its way, producing a series of rapids and falls which the observer often beholds with amazement. The river is continually in a foam for nine miles, and the wonder is that such a furious and heavy volume of water should not have prostrated everything before it. The sandstone, grauwacke, and the argillite, the latter of which stands on its edges, have opposed but a feeble barrier; but the trap species, resisting with the firmness, as it has the color of cast-iron, stand in masses which threaten the life and safety of everything which may be hurled against them. I found a loose specimen of sulphuret of lead and some common quartz in place in the slate rock, a vein of clorite slate, and a locality of coarse graphite, to reward my search.
The Portage aux Coteaux, which is over the basetting edges of the argillite, will give a lively idea of the effects of this rock upon the feet of the loaded voyageurs.
The sandstone is last seen near the Galley on the Nine Mile Portage. Above the Knife Portage, some eight miles higher, vast black boulders of hornblendic and basaltic blocks, are more frequent; and these masses are observed to be more angular in their shapes than the boulders and blocks of kindred character encountered on the shores of Lakes Superior and Huron. There is a vast sphagnous formation, which spreads westwardly from the head of the Coteau Portage, and gives rise to the remote tributaries of Milles lac and Rum River. Much of this consists of what the Indians term muskeeg, or elastic bog. Hurricanes and tempests have made fearful inroads upon areas of its timber, and it is seldom crossed, even by the Indians. This tract lies east of the summit of sand-hills and drift, which environ Sandy Lake, the Komtaguma of the Chippewas. The portage of the Savanna River, a tributary of the St. Louis, is the route pursued by persons with canoes; there is no other species of water craft adapted to this navigation. But wherever crossed, this swamp-land tract imposes labor and toil which are of no ordinary cast. It is the equivalent of the argillite which has been broken down and disintegrated, forming beds of clay soil which are impervious to the water, and we way regard this ancient slate formation of the true source of the St. Lawrence tributaries, as the remote origin of those extensive beds of an argillaceous kind, which exist at many places in the lower lakes and plains.
Immediately west of the Savanna Portage, the Komtaguma summit is reached. This summit consists wholly of arid pebble and boulder drift of the elder period. It exhibits evidences of broken-down amygdaloids, which not only furnish a part of its pebbles, but also of the contents of this stratum, in numerous agates and other subspecies of the quartz family which are found scattered over the surface. This is, in fact, the origin of that extensive diffusion of these species, which is found in the valley of the Upper Mississippi, as at Lake Pepin, &c., and which has even been traced, in small pieces, as low as St. Louis and Herculaneum in Missouri.227 We may conclude that the ancient sandstones, slates, and rubblestone, and amygdaloids, of which traces still remain, were swept from the summit of the Mississippi by those ancient floods which appear to have diffused the boulder drift from the North.
Sandy Lake.—The first view of this body of water was obtained from one of those eminences situated at the influx of the west Savanna River.
This lake is bounded, on its western borders, by the delta of the Mississippi; its outlet is about two miles in length. We here first beheld the object of our search. The soil on its banks is of the richest alluvial character. From this point, dense forests and a moderately elevated soil, varying from three or four to fifteen feet, confined the view, on either side, during more than two days’ march. On the third day after leaving Sandy Lake, at an early hour, we reached the Falls of Pakágama. Here the rock strata show themselves for the first time on the Mississippi, in a prominent ledge of quartz rock of a gray color. Through this formation the Mississippi, here narrowed to less than half its width, forces a passage. The fall of its level in about fifty rods may be sixteen or eighteen feet. There is no cascade or leap, properly so called, but a foaming channel of extraordinary velocity, which it is alike impossible to ascend or descend with any species of water craft. It lies in the shape of an elbow. We made the portage on the north side.
Pakágama Summit.—The observer, when he has surmounted the summit, immediately enters on a theatre of savannas, level to the eye, and elevated but little above the water. Vistas of grass, reeds, and aquatic plants spread in every direction. On these grassy plains the river winds about, doubling and redoubling on itself, and increasing its cord of distance in a ratio which, by the most moderate computation, would seem extravagant. On those plateaux, and the small rivers and lakes connected with them, the wild rice reaches the highest state of perfection.
Our men toiled with their paddles till the third day, through this unparalleled maze of water and plants, when we reached the summit of the Upper Red Cedar or Cass Lake, where we encamped. In this distance no rock strata appeared, nor any formation other than a jutting ridge of sand, or an alluvial plain. Plateau on plateau had, indeed, carried us from one level or basin to another, like a pair of steps, till we had reached our extreme height.
Cass Lake Basin.—From estimates made, this lake is shown to lie at thirteen hundred and thirty feet above the Atlantic.228 This is a small elevation, when we consider it as lying on the southern flank of the transverse formation which forms the connecting link with the Rocky Mountains. A rise or a subsidence of this part of the continent to this amount, would throw the Hudson’s Bay and Arctic waters down the Mississippi valley. The scenery of its coasts is in part arenaceous plains, and in part arable land, yielding corn to the Indians.
Sources of the Mississippi.—In order to understand the geology of this region, it is necessary to premise, that the St. Lawrence, the Hudson’s Bay, and the Mexican Gulf waters are separated by a ridge or watershed of diluvial hills, called the Hauteur des Terres, which begins immediately west of the basin of the Rainy Lakes and Rainy Lake River. This high ground subtends the utmost sources of the Mississippi, and reaches to the summit of Ottertail Lake, where it divides the tributaries of the Red River of Lake Winnepec from those of the Des Corbeau, or Great Crow-Wing River.
Within this basin, which circumscribes a sweep of several hundred miles, there appears to have been deposited, upon the trap and primary rocks which form its nucleus, a sedimentary argillaceous deposit, capable of containing water. Upon this, the sand and pebble drift reposes in strata of unequal thickness, and the sand is often developed in ridges and plains, bearing species of the pine. The effect has been, that the immense amount of vapor condensed upon these summits, and falling in dews, rains, and snows, being arrested by the impervious subsoil of clay, has concentrated itself in innumerable lakes, of all imaginable forms, from half a mile to thirty miles long. These are connected by a network of rivers, which pour their redundancy into the Mississippi, and keep up a circulation over the whole vast area. The sand plains often resting around the shores of these lakes create the impression of bodies of water resting on sand, which is a fallacy. Some of these bodies of water are choked up, or not well drained, and overflow their borders, forming sphagnous tracts. Hence the frequent succession of arid sand plains, impassable muskeegs, and arable areas on the same plateaux. Every system of the latter, of the same altitude, constitutes a plateau. The highest of these is the absolute source of the Mississippi waters. The next descending series forms another plateau, and so on, till the river finally plunges over St. Anthony’s Falls.
In this descending series of plateaux, the Cass, Leech Lake, and Little Lake Winnipec form the third and fourth levels.
In descending the Mississippi below the Pakágama, the first stratum of rock, which rises through the delta of the river, occurs between the mouth of the Nokasippi and Elm Rivers, below the influx of the Great De Corbeau. This rock, which is greenstone trap, rises conspicuously in the bed of the stream, in a rocky isle seated in the rapid called—I know not with what propriety—the Big Falls, or Grande Chute. The precipitous and angular falls of this striking object decide that the bed of the stream is at this point on the igneous granitical and greenstone series. This formation is seen at a few points above the water, until we pass some bold and striking eminences of shining and highly crystalline hornblendic sienite, which rises in the elevation called by us Peace Rock, on the left bank, near the Osaukis Rapids. This rock lies directly opposite to the principal encampment on the 27th of July, which was on an elevated prairie on the west bank. To this point a delegation of Sioux had ascended on an embassy of peace from Fort Snelling to the Chippewas, having affixed on a pole what the exploring party called a bark letter, the ideas being represented symbolically by a species of picture writing, or hieroglyphics. In allusion to this embassy, this locality was called the Peace Rock. This rock is sienite. It is highly crystalline, and extends several miles. Its position must be, from the best accounts, in north latitude about 44° 30´. From this point to Rum River, a distance of seventy miles, no other point of the intrusion of this formation above the prairie soil was observed.
Introduction of the Palæontological Rocks.—After passing some fifty miles below this locality there are evidences that the river, in its progress south, has now reached the vicinity of the great carboniferous and metalliferous formations, which, for so great a length, and in so striking a manner, characterize both banks of the Mississippi below St. Anthony’s Falls. About nine or ten miles before reaching these Falls, this change of geological character is developed; and on reaching the Falls the river is found to be precipitated, at one leap, over strata of white sandstone, overlaid by the metalliferous limestone. The channel is divided by an island, and drops in single sheets, about sixteen to eighteen feet, exclusive of the swift water above the brink, or of the rapids for several hundred yards below. This sandstone is composed of grains of pure and nearly limpid quartz, held together by the cohesion of aggregation. If my observations were well taken it embraces, sparingly, orbicular masses of hornblende. It is horizontal, and constitutes, in some places, walls of stratification, which are remarkable for their whiteness and purity. This sandstone is overlaid by the cliff limestone, the same in character, which assumes at some points a silicious, and at others, a magnesian character. It is manifestly the same great metalliferous rock which accompanies the lead ore of Missouri and mines of Peosta or Dubuque. There rests upon it the elder drift stratum of boulders, pebble, and loam, which marks the entire valley. This latter embraces boulders of quartz and hornblende rock, along with limestones and sandstones. It is overlaid by about eighteen inches of black alluvial carbonaceous mould.
From St. Anthony’s Falls the river is perpetually walled on either side with those high and picturesque cliffs which give it so imposing and varied an appearance, and its current flows on with a majesty which seems to the imagination to make it rejoice in its might, confident of a power which will enable it to reach and carry its name to the ocean in its unchanged integrity.
St. Peter’s River and Valley.—The importance, fertility, and value of this tributary have particularly impressed every member of the party. Its position as the central point of the Sioux power, and its border position to the Chippewas, the representative tribe of the great Algonquin family, render it now a place of note, which fully justifies the policy of the department in establishing a military post at the confluence of the river; and the importance cannot soon pass away, in the progress of the settlement of the Mississippi Valley.229 It is the great route of communication with the valley of the Red River of the North, and the agricultural and trading settlements of Lord Selkirk in that fertile valley, and its complete exploration by a public officer is desirable, if not demanded.230
Of its geological character but little is known, and that connects it with both the great formations which have been noticed as succeeding each other at the great Peace Rock. That the granitical formation reaches it at a high point is probable, from the large reported boulders. The Indians bring from the blue earth fork of it, one of their most esteemed green and blue argillaceous pigments, of which the coloring matter appears to be carbonate of copper. They also bring from the Coteau des Prairie, probably Carver’s “shining mountains,” specimens of that fine and beautiful red pipe stone, which has so long been known to be used by them for that purpose. This mineral is fissile, and moderately hard, which renders it fit for their peculiar ripe sculptures. I found small masses of native copper in the drift stratum at the mouth of this stream, on the top of the cliffs on the Mississippi, opposite the mouth of the St. Peter’s.
Crystalline Sand Rock.—This stratum reveals the same crystalline structure which is so remarkable in the sandstone caves, near the Potosi road, in the county of St. Genevieve, Missouri; and the sand obtained from it, like that mineral, would probably fuse, with alkali, in a moderate heat, and constitute an excellent material for the manufacture of glass. It is also, like the Missouri sandstone, cavernous. In both situations, these caves appear to be due to water escaping through fissures of the rock, where its cohesion is feeble, carrying it away grain by grain. In stopping at one of these caves, about twelve miles below St. Peter’s, we found this cause of structure verified by a lively spring and pond of limpid water flowing out of it.
Valley of the St. Croix.—This river originates in an elevated range of the elder sand and pebble drift, which lies on the summit between the Mississippi system of formations, and the Lake Superior basin. It communicates with the Brulé, which is “Goddard’s River” of Carver, and with the Mauvaise or Bad River of that basin. Specimens of native copper have been found on Snake River, one of its tributaries.231
Geological Monuments.—In descending the river for the distance of about one hundred miles below St. Anthony’s Falls, my attention was arrested, on visiting the high grounds, by a species of natural monuments, which appear as if made by human hands seen at a distance, but appear to be the results of the degradation and wasting away, on the Huttonian theory, of all but these, probably harder, portions of the strata.
Lake Pepin.—This sheet commends itself to notice by its extent and picturesque features. It is an expansion of the river, about twenty-four miles long, and two or three wide. Both its borders and bed reveal the drift stratum, and the observer recognizes here, boulders of the peculiar stratification which has, in ancient periods, characterized the high plateaux about the sources of the river. Such are its hornblendic, sienite, quartz, trap, and amygdaloid pebbles, and that variety of the quartz family which assumes the form of the agate and other kindred species. Moved as these materials are annually, lower and lower, by the impetus of the stream, other supplies, it may be inferred, are still furnished by the shifting sand and gravel bars from above. The mass must submit to considerable abrasion by this change, and the diminished size of the drifted masses become a sort of measure of the distance at which they are found from their parent beds.
Chippewa River.—This stream is the first to bring in a vast mass of moving sand. Its volume of water is large, which it gathers from the high diluvial plains that spread southwest of the Porcupine Mountains, and about the sources of the Wisconsin, the Montreal, and the St. Croix Rivers, with which it originates.
Trompeldo (Le Montaine des Tromps d’Eaux).—This island mountain stands as if to dispute the passage of the Mississippi, whose channel it divides into two portions. Distinct from its height, which appears to correspond with the contiguous cliffs, and in the large amount of fresh debris at its base, it presents nothing peculiar in its geology.
Painted Rock.—This vicinity is chiefly noted for its large and fine specimens of fresh-water shells.
Wisconsin.—Like the Chippewa, this stream brings down in its floods, vast quantities of loose sand, which tend to the formation of bars and temporary islands. It originates in the same elevated plains, and bespeaks a considerable area at its sources, which must be arid. It is a region, however, in which lakes and rice lands abound, and it may, in this respect, be geologically of the same formation as the higher plateaux of the Mississippi, above the Sandy Lake summit. Its sides produce many species to enrich our fresh-water Conchology.
Lead Mines of Peosta and Dubuque.—In my researches into the mineral geography of Missouri, in 1818 and 1819, I had explored a district of country between the rivers Merrimak and St. Francis, and on the Ozarks, which revealed many traits which it has in common with the Upper Mississippi. There, as here, the mineral deposits appear to be, in many cases, in a red marly clay, whether the clay is overlaid by the calcareous rock or not. There, as here, also, the limestone and sandstone strata are perfectly horizontal. The leads of ore appear, in this section, to be followed with more certainty, agreeable to the points of the compass; but this may happen, to some extent, because the practice of mining on individual account, with windlass and buckets, in the Missouri district, has led common observers to be more indifferent to exact scientific methods. To say that the digging, at these mines, is equally, or more productive, is perhaps just. Capital and labor have been rewarded in both sections of the country, in proportion as they have been perseveringly and judiciously expended.
I found much of the ore, which is a sulphuret, at Dubuque’s Mines, lying in east and west leads. These leads were generally pursued in caves, or, more properly, fissures in the rock. In one of the excavations which I visited, the digging was continued horizontally under the first stratum of rock, after an excavation had been made perpendicularly, through the top soil and calcareous rock, perhaps thirty feet. The ore is a broad-grained cubical galena, easily reduced, and bids fair very greatly to enhance the value and resources of this section of the West.
Similar mines exist at Mississinawa, and the River Au Fevé,232 both on the eastern or left bank of the Mississippi. And a system of leasing or management, such as I have suggested for the Missouri mines, appears equally desirable.
Quartz Geodes.—The amount of silex in the cliff limestone is such, in some conditions of it, as to justify the term silico-calcareous. This condition of the rock at the passage of the Mississippi through the Rock River and Des Moines Rapids, is such as to produce a very striking locality of highly crystalline quartz geodes, which accumulates in the bed of the stream. Many of these geodes are from a foot to twenty-two inches in diameter, and on breaking them they exhibit resplendent crystals of limpid quartz. Sometimes these are amethystine; in other cases they present surfaces of chalcedony or cacholong. The latter minerals, if obtained from the rock, and before unduly hardening by exposure, would probably furnish a suitable basis for lapidaries.
Intermediate Country in the Direction to Green Bay.—There is a line which separates, on the north, the granitical and trap region from the metal-bearing limestone, and its supporting sandstone. This formation of the elder series of rocks, having been traced to the south shore of Lake Superior, and having been seen to constitute the supporting bed of the alluviums and diluviums of the Upper Mississippi, above the Peace Rock, it may subserve the purpose of inquiry to trace this line of junction by its probable and observed boundaries.
The line may be commenced where it crosses the Mississippi, at the Peace Rock, and extended to the St. Croix, the falls of which are on the trap-rock, to the sources of the Chippewa at Lac du Flambeau, and the Wisconsin near Plover Portage. The source of Fox River runs amid uprising masses of sienite, and this formation appears to pass thence northeasterly, across the Upper Menominee, to the district of the Totosh and Cradle-Top Mountains, west of Chocolate River, on the shores of Lake Superior.
I observed the crystalline sandstone and its overlying cliff limestone, along the valley of the Wisconsin, where ancient excavations for lead ore have been made. There is an entire preservation of its characters, and no reason occurs why its mineralogical contents should not prove, in some positions, as valuable as they have been found in Missouri, or in the Dubuque district west of the Mississippi.
On reaching the Wisconsin Portage, the limestone is found to have been swept by diluvial action, from its supporting sand rock. Such is its position not far north of the highest of the four lakes, and again at Lake Puckway, in descending the Fox River; consequently, there are no lead discoveries in this region. On coming to the calcareous rock, which is developed along the channel of the river, below Winnebago Lake, it appears rather to belong to the lake system of deposits. Its superior stratum lies in patches, or limited districts, which appear to have been left by drift action. Petrefactions are found in these districts, and the character of the rock is dark, compact, or shelly. The lower series of deposits, such as they appear at the Kakala Rapids, at Washington Harbor, in the entrance to Green Bay, and in the cliffs north of Sturgeon Bay and Portage, are manifestly of the same age and general character as the inferior stratum of Michilimackinac and the Manatouline chain.
Basin of Lake Michigan.—This basin, stretching from the north to the south nearly four hundred miles, lies deeply in the series of formation of limestones, sandstone, and schists, to which we apply the term of the Michilimackinac system. Its north and west shores are skirted from Green Bay to a point north of the Sheboygan, with the calcareous stratum. At this point, the ancient drift, the lacustrine clay of Milwaukie and the prairie diluvium of Chicago, constitute a succession, of which the surface is a slightly waving line of the most fertile soils.
Among the pebbles cast ashore at the southern head of this lake I observed slaty coal. It seems, indeed, the only one of the lakes which reaches south into the coal basin of Illinois. If the level at which coal is found on the Illinois were followed through, it would issue in the basin of the lake below low-water mark. Digging for this mineral on the Chicago summit, promises indeed not to be unsupported by sound hypothesis.
After passing Chicago, of which a sketch is added, the sands which begin to accumulate at the Konamik, the River du Chemin, and the St. Joseph’s River,233 appear in still more prominent ridges, skirting the eastern coasts to and beyond Grand River. These sands, which are the accumulations of winds, are cast on the arable land, much in the manner that has been noticed at the Grand Sable on Lake Superior, and reach the character of striking dunes at the coast denominated the Sleeping Bear. The winds which periodically set from the western shore, produce continual abrasions of its softer materials, and are the sole cause of these intrusive sand-hills. Pent up behind them, the water is a cause of malaria to local districts of country, and many of the small rivers upon this side are periodically choked with sand. The sketch transmitted of this bleak dune-coast (omitted here), as it is seen at the mouth of Maskigon Lake, will convey a false idea of the value of this coast, even half a mile from the spot where the surf beats. It is designed to show the air of aridity which the mere coast line presents. The stratification regains its ordinary level and appearance before reaching the Plate or Omicomico River, and the peninsula of the Grand Traverse Bay, and the settlements of the Ottawa Indians on Little Traverse Bay, afford tracts of fertile lands. Point Wagonshonce consists of a stratum of limestone of little elevation, which constitutes the southeast cape of the strait. Here a lighthouse is needed to direct the mariner.
Lake Huron.—Notices of this sheet of water have been given in our outward voyage. It appears rather as the junction of separate lakes which have had their basins fretted into one another, than as one original lake. Michigan is connected with it through the Straits of Michilimackinac. The Georgian Bay, north of the Manatouline chain, seems quite distinct. The Saganaw Bay is an element of another kind. The Manitouline chain separates the calcareous and granitic region, and its numerous trap and basaltic islands towards the north shore, of which there are many thousands, denote that it has been the scene of geological disturbance of an extraordinary kind.
Ulterior Conclusions.—In taking these several views of the geological structure of the Northwest—of the Lake Superior basin, and of the valleys of the St. Louis River—the region about the Upper Mississippi, its striking change at the Falls of St. Anthony—and the valleys of the Wisconsin and Fox Rivers, and the basins of Lakes Michigan and Huron, I am aware of the temerity of my task. Allowance must, however, be made for the rapidity of my transit over regions where the question was often the safety and personal subsistence of the party. A very large and diversified area was passed over in a short time. At no place was it possible to make elaborate observations. A thousand inconveniences were felt, but they were felt as the pressure of so many small causes impeding the execution of a great enterprise. A sketch has been made, which, it is hoped, will reveal something of the physical history and lineaments of the country. These glimpses at wild scenes, heretofore hid from the curious eye of man, have been made, at all points, with the utmost avidity. I have courted every opportunity to accumulate facts, and I owe much to the distinguished civilian who has led the party so successfully through scenes of toil and danger, not always unexpected, but always met in a calm, bold, and proper spirit, which has served to inspire confidence in all; to him, and to each one of my associates, I owe much on the score of comity and personal amenity and forbearance; and I have been made to feel, in the remotest solitudes, how easy it is to execute a duty when all conspire to facilitate it.
The views herein expressed are generalized in two geological maps (hereto prefixed), which, it is believed, will help to fix the facts in the mind. They exhibit the facts noticed, in connection with the theory established by them, and by all my observations, of the construction of this part of the continent.
The mineralogy of the regions visited is condensed in the following summary, drawn from my notes, which, it is believed, constitutes an appropriate conclusion to this report.
With the exception of one species, namely, the ores of copper, the region has not proved as attractive in this department as I found the metalliferous surface of Missouri. There are but few traces of mining, and those of an exceedingly ancient character, in the copper region of Lake Superior. The excavations in search of lead ore on the Upper Mississippi do not date back many years, but the indications are such as to show that few countries, even Missouri, exceed them in promises of mineral wealth.
I have employed the lapse of time between the termination of the exploration and the present moment, to extend my mineralogical observations to some parts of the Mississippi Valley which were not included in the line of the expedition, but which were visited in the following year, in the service of the Government, namely, the Miami of the Lakes, and Wabash Valleys, the Cave in Rock Region in Lower Illinois, and the Valley of the River Illinois. The whole is concentrated in the following notices:—
Tabular View of Minerals observed in the Northwest.
| I. ORES. | ||||
|---|---|---|---|---|
| Genera. | Species. | Subspecies. | Varieties. | |
| Metallic minerals | Copper | Native copper. | ||
| Green carbonate of copper | Fibrous. | |||
| Compact. | ||||
| Lead | Sulphuret of lead | Common. | ||
| Zinc | Sulphuret of zinc | Blende. | ||
| Iron | Sulphuret of iron | Common. | ||
| Radiated. | ||||
| Spheroidal. | ||||
| Cellular. | ||||
| Hepatie. | ||||
| Magnetic oxide of iron | Iron sand. | |||
| Specular oxide of iron. | Micaceous. | |||
| Red oxide of iron | Ochrey. | |||
| Scaly. | ||||
| Compact. | ||||
| Brown oxide of iron | Ochrey. | |||
| Silver. | ||||
| II. EARTHS AND STONES. | |||
|---|---|---|---|
| Genus. | Species. | Varieties. | |
| Silicious minerals | Quartz | Common quartz | Milky. |
| Radiated. | |||
| Tabular. | |||
| Greasy. | |||
| Granular. | |||
| Arenaceous. | |||
| Pseudomorphous. | |||
| Amethystine. | |||
| Amethyst. | |||
| Ferruginous quartz | Yellow. | ||
| Red. | |||
| Prase. | |||
| Chalcedony | Common. | ||
| Cacholong. | |||
| Carnelian. | |||
| Sardonyx. | |||
| Agate. | |||
| Hornstone. | |||
| Jasper | Common. | ||
| Striped. | |||
| Red. | |||
| Heliotrope. | |||
| Opal | Common. | ||
| Silicious slate | Common. | ||
| Basanite. | |||
| Petrosilex | |||
| Mica | Common. | ||
| Gold yellow. | |||
| Schorl | Common. | ||
| Indicolite. | |||
| Feldspar | Common. | ||
| Prehnite | Radiated. | ||
| Hornblende | Common. | ||
| Actynolite. | |||
| Woodstone | Mineralized wood. | ||
| Agatized wood. | |||
| Calcareous Minerals | |||
| Carbonate of lime | Calcareous spar | Crystalized. | |
| Lamellar. | |||
| Granular limestone | |||
| Compact limestone | Common. | ||
| Earthy. | |||
| Agaric mineral | Common. | ||
| Fossil farina. | |||
| Concreted carbonate of lime | Oolite. | ||
| Calcareous sinter | Stalactite. | ||
| Stalagmite. | |||
| Calcareous tufa. | |||
| Pseudomorphous carbonate of lime. | |||
| Marl | Ludus helmontii. | ||
| Sulphate of lime | Gypsum | Fibrous. | |
| Granular. | |||
| Granularly foliated. | |||
| Earthy. | |||
| Fluate of lime | Fluorspar. | ||
| Genus. | Varieties. | ||
| Aluminous minerals | Argillaceous slate | Argillite. | |
| Bituminous shale. | |||
| Chlorite | Chlorite slate. | ||
| Staurotide. | |||
| Clay | Potters’ clay. | ||
| Pipe clay. | |||
| Variegated clay. | |||
| Blue sulphated clay. | |||
| Green sulphated clay. | |||
| Opwagunite. | |||
| Magnesian minerals | Serpentine | Common serpentine. | |
| Steatite | Steatite. | ||
| Asbestus | Com. asbestus. | ||
| Barytic minerals | Sulphate of barytes | Lamellar. | |
| Strontian | Sulphate of strontian | Foliated. | |
| III.COMBUSTIBLES. | |||
| Bituminous minerals | Bitumen | Petroleum. | |
| Maltha. | |||
| Asphaltum. | |||
| Graphite | Granular graphite. | ||
| Coal | Slate coal. | ||
| IV. SALTS. | |||
| Soda | Muriate of soda | Native salt. | |
| Salt springs. | |||
| Alkaline sulphate of alumina | Alum. | ||
a. Metallic Minerals.
1. Copper.
This metal is frequently found, in detached masses, in the diluvial soil along the southern shore of Lake Superior, and in the high and barren tract included between Lakes Huron, Michigan, and Superior, and the Mississippi River, as general boundaries. Thus, it has been found upon the sources of the Menomonie, Wisconsin, Chippewa, St. Croix, and Ontonagon Rivers, but most constantly, and in the greatest quantity, upon the latter. There are many localities known only to the aborigines, who appear to set some value upon it, and have been in the habit of employing the most malleable pieces in several ways from the earliest times. It occurs mostly in detached masses, resting upon, or imbedded in, diluvial soil. These masses, which vary in size, are sometimes connected with isolated fragments of rock. Such is the geognostic position of the great mass of native copper upon the banks of the Ontonagon, which has been variously estimated to weigh from two to five tons. This extraordinary mass is situated at the base of a diluvial precipice composed of reddish loam and mixed boulders and pebbles of granite, greenstone, quartz, and sandstone and diallage rocks. The nearest strata, in situ, are red sandstone, grauwacke, and greenstone trap. A company of miners was formerly employed in searching for copper mines upon the banks of this river. They dug down about forty feet into the diluvial soil, at a spot where a green-colored water issued from the hill. In sinking this pit, several masses of native copper were found, and they discovered, as their report indicates, the same metal “imbedded in stone.” But the enterprise was abandoned, in consequence of the falling in of the pit.
At Keweena Point, on Lake Superior, I found native copper along the shore of the lake, constituting small masses in pebbles, and, in one instance, in a mass of several pounds’ weight, which was found in the Ontonagon Valley. I also observed the green carbonate of copper, in several places, in the detritus. The strata of this point appear to be charged with this mineral, particularly in its native forms. Hardly a mass of the loose rock is without some trace of the metal, or its oxides or salts. It would be difficult, on any known principles, to resist the testimony which is offered, by every observer, to favor the idea that extensive and very valuable mines exist. The whole lake shore, from this peninsula to the Montreal River, is replete with these evidences.
There are indications that this mineral pervades the rocks and soils, in a radius of one hundred and fifty miles or more, south and west of this central point. It has been discovered at the sources of the Menominee, Chippewa, Montreal, and St. Croix, and even at more distant points.
At St. Peter’s, in digging down for the purpose of quarrying the rock, about eighteen inches depth of dark alluvium was passed; then a deposit of diluvial soil, with large fragments of limestone, greenstone, quartz rock, &c., about six feet; and, lastly, one foot of small pebbles, &c., constituting the copper diluvium. No large mass was found; nor any veins in the rock.
2. Lead.
The only ore of lead known to exist within the limits to which these remarks are confined, is the sulphuret. In the year 1780, Peosta, a woman of the Misquakee, or Fox tribe of Indians, discovered a lead mine upon the west banks of the Mississippi, at the computed distance of twenty-five leagues below Prairie du Chien, which the Indians, in 1788, gave Julian Dubuque a right to work. This permission was partially confirmed by the Baron de Carondelet, Governor of Louisiana, in 1796. No patent was, however, issued; but Dubuque continued to prosecute the mining business to the period of his death, which happened in 1810, when the mines were again claimed by the original proprietors.
The ore is the common sulphuret of lead, or galena, which Dubuque stated to have yielded him seventy-five per cent. in smelting in the large way. He usually made from 20,000 to 40,000 pounds per annum.
I made a cursory visit to these mines, and found them worked by the Fox Indians, but in a very imperfect manner. They cover a considerable area, commencing at the mouth of the Makokketa River, sixty miles below Prairie du Chien. Traces of the ore are found, also, on the east bank of the Mississippi at several points. It occurs disseminated in a reddish loam, resting upon limestone rock, and is sometimes seen in small veins pervading the rock; but it has been chiefly explored in diluvial soil. It generally occurs in beds having little width, and runs in a direct course towards the cardinal points. They are sometimes traced into a crevice of the rock. At this stage of the pursuit, most of the diggings have been abandoned. Little spar or crystalline matrix is found in connection with the ore. It is generally enveloped by a reddish, compact earth, or marly clay. Occasionally, masses of calcareous spar occur; less frequently, sulphate of barytes, green iron earth, and ochrey brown oxide of iron. I did not observe any masses of radiated quartz, which form so conspicuous a trait in the surface of the metalliferous diluvion of the mining district of Missouri.
Sufficient attention does not appear to have been bestowed, by mineralogists, upon the metalliferous soil of the Mississippi Valley. It is certainly very remarkable that such vast deposits of lead ore, accompanied by veins of sulphate of barytes, calc spar, and other crystallized bodies, should be found in alluvial beds; and it would be very interesting to ascertain whether any analogous formations exist in Europe, or in any other part of the earth’s surface. It is one of the most striking features of this deposit, that the ore, spars, &c., do not appear as the debris of older formations, and have no marks of having been worn or abraded, like those extraneous masses of rock which are very common in the alluvial soil of our continent. The lead ore and accompanying minerals appear to have been crystallized in the situations where they are now found. We should, perhaps, except from this remark the species of lead called gravel ore by the miners, which is in rounded lumps, and is never accompanied by spars.
Sulphuret of lead is also found near the spot where the small River Sissinaway enters the Mississippi, and two leagues south of it, upon the banks of the River Aux Fevre, at both of which places considerable quantities have been raised, and continue to be raised, for the purposes of smelting, by the Fox and Sac tribes of Indians. At these places, it is most frequently connected with a gangue of heavy spar and calcareous spar, with pyrites of iron. I procured from a trader, at Dubuque, several masses of galena crystallized in cubes and octahedrons.
In descending the Upper Mississippi, a specimen of galena was exhibited to me, by a Sioux Indian, at the village of the Red Wing, six miles above Lake Pepin, said to have been procured in that vicinity. Galena is also reported to have been discovered in several places on the south side of the Wisconsin River, and these localities may be entitled to future notice, as furnishing important hints.
3. Zinc.
The sulphuret of zinc (black blende) is found disseminated in limestone rock along the banks of Fox River, between the post of Green Bay and Winnebago Lake. Although frequently seen in small masses, no body of it is known to exist. I also found blende, in small, orbicular masses of calcareous marl, along the east shore of Lake Michigan, between the Rivers St. Joseph and Kikalemazo.
4. Iron.
This mineral is distributed, in several of its forms, throughout the region visited, although but little attention has yet been directed to its exploration. In the basin of Lake Superior it exists, in valuable masses, in the form of a magnetic oxide, on the coasts of the lake between Gitchi Sebing (Great River), called by the French Chocolate River, and Granite Point. Specimens from Dead River (Riviere du Morts) and Carp River, the Namabin of the Indians, in this district, denote the latter to be the chief locality. It is the iron glance, and occurs in mountain masses.
Sulphuret of Iron.—This variety is found, in limited quantities, in a state of crystallization, in clay beds, on the west shore of Lake Michigan, between Milwaukie and Chicago. It is frequently in the form of a cube or an octahedron. Some of the crystals are in lumps of several pounds’ weight, with a metallic lustre. Often the masses, on being broken, are found radiated, sometimes cellular, and occasionally irised.
Iron Sand.—The breaking-up and prostration of the sandstone and other sedimentary formations, along the shores of lakes Michigan, Huron, and Superior, liberates this ore in considerable quantities. It arranges itself, on the principle of its specific gravities, in separate strata along the sandy shores, where it invariably occupies the lowest position at and below the water’s edge. The shores of Fond du Lac, on Lake Superior, may be particularly mentioned as an abundant locality.
Micaceous Oxide of Iron.—In detached mass, among the debris of the River St. Louis and of Fond du Lac. It exists in veins in the clay slate which characterizes the banks of this river.
Ochrey Red Oxide of Iron. (Red ochre)—Is produced near a spot called the Big Stone, on the head of the River St. Peter’s. It is said to occur in a loose form, in a stratum of several inches thick, lying below the soil of a level dry prairie or plain. The Sioux Indians, who employ it as a paint, make this statement. The color of a portion given to me by them is of a bright red; and a considerable proportion of the mass is in a state of minute division. Particles of quartz are occasionally mixed with it. This ore of iron is also represented to be found in the prairies north of Gros Point, along the west shore of Lake Michigan, between Milwaukie and Chicago.
Ochrey red oxide of iron occurs on the shores of Big Stone Lake, at the source of the St. Peter’s River. A large spring rises from a level, dry plain, a few feet beyond which the mineral occurs. The Indians, who employ it as a pigment, take it up with their knives. The stratum is about eight inches thick, but just below the surface it is mixed with common earth. The spring of water is pure and unadulterated.
5. Silver.
The belief in the existence of silver ore in the region of the lakes, and particularly on Lake Superior, seems to have early prevailed. So much confidence was placed in the reports of its existence, that Henry tells when a company was formed in England for exploring the copper mines of Lake Superior (A. D. 1771), they were impelled to the search more from an expectation of the silver, which it was hoped would be found in connection with it, than from the copper.234
b. Silicious Minerals.
1. Quartz.
This interesting species being distributed in its numerous varieties throughout the region visited, I shall confine my notices to a few localities.
Subs. 1.—Common Quartz.
Occurs in the form of large water-worn masses along the shores of Lakes Huron, Michigan, and Superior. Also, in veins in the granite of Lake Superior, and in the argillite of St. Louis River. These localities all consist of the opaque varieties, with a slight degree of translucence in some places. It exists in mass at Huron Bay, Lake Superior, and in fragments of red jasper on Sugar Island, St. Mary’s River.
1. Radiated Quartz.—In detached masses on the Grange, and also at the rapids of the River Desmoines, on the Upper Mississippi. At the Grange, the crystals, which are usually minute, sometimes possess a cinnamon color, or pass into a variety of crystallized ferruginous quartz.
2. Tabular Quartz.—In small, flattened masses along the shores of Lake Pepin. These masses are transparent, or only translucent. Their color is generally white, but sometimes yellow. They appear to be closely allied to chalcedony.
3. Greasy Quartz.—In detached masses along the shores of Lake Superior.
4. Granular Quartz.—At the Falls of Puckaiguma, on the Upper Mississippi, in large, compact beds rising through the soil. Also, in some conditions of the cliffs commencing at the Falls of St. Anthony, Carrer’s Cave, &c.
5. Arenaceous Quartz.—This is sometimes the condition of fine, even-grained, translucent sand rock of the preceding localities. Valuable as an ingredient of glass.
6. Pseudomorphous Quartz.—On the shores of Lake Pepin, occasionally. These masses appear to have taken their crystalline impress from rhomboidal crystals of carbonate of lime.
7. Amethystine Quartz.—In the trap-rock of Lake Superior.
Subs. 2.—Amethyst.
This mineral occurs most frequently in the condition of amethystine quartz, in hexahedral prisms, lining the interior of geodes, in the bed of the River Desmoines, and on the Rock Rapids, in the channel of the Mississippi. The crystals which I have examined are generally limpid, with a high lustre, and of a pale violet color. Sometimes the tinge of color approaches to a full red, or is only apparent in the summit of the crystal. These geodes are sometimes eight or ten inches in diameter, with a rough and dark-colored exterior, often so nearly spherical as to resemble cannon balls. Some of the finest specimens I have observed from this locality are preserved in the museum of Gov. Clarke, at St. Louis, Missouri.
Subs. 3.—Ferruginous Quartz.
In amorphous masses, of a deep-red, brown, or yellowish-red color, along the southern shore of Lake Superior. Likewise, crystallized, in very minute hexagonal prisms, terminated by six-sided pyramids, of a reddish color, on the summit and declivities of the Grange de Terre.
Subs. 4.—Prase.
In the drift of Lake Superior. Its color is a light green and not fully translucent. It possesses a hardness and a lustre intermediate between waxy and resinous.
Subs. 5.—Chalcedony.
1. Common Chalcedony.—In globular or reniform masses imbedded in trap-rock, on the Peninsula of Keweena, Lake Superior. It is found sometimes in association with other quartz minerals. Its color is white or gray, sometimes veined or spotted with red. Also, constituting the interior lining of geodes at the rapids of Rock Island and the River Desmoines. These geodes, on breaking, often present a mammillary surface. In the form of translucent fragments, with a highly conchoidal fracture, among the debris of the shores of Lake Pepin. These fragments possess an extremely delicate texture, color, and lustre.
2. Cacholong.—Some loose fragments of this mineral exist along the west shore of Lake Michigan, between Green Bay and Chicago. These fragments possess small cavities studded over with very minute and perfect crystals of quartz.
3. Carnelian.—This mineral occurs in fragments in the debris of Lake Superior; also, in the amygdaloid; also, around the shores of the Upper Mississippi. Its color is various shades of red, or yellowish red, sometimes spotted or clouded, fully translucent, and occasionally presenting a considerable richness and beauty. Most commonly, the fragments are too small to be applied to the purposes of jewelry. Sometimes it is seen in very regular spheroidal masses, which contain a nucleus of radiated quartz. Some of the specimens would be considered as sardonyx.
4. Agate.—Is found with the preceding. It is more frequently found in larger masses, in the rock, which are sometimes spheroidal, reniform, or globular. These agates are chiefly arranged in concentric layers, which are white, red, yellow, &c., according to the colors of the different varieties of chalcedonies, carnelians, &c., of which they are composed. A close inspection would also separate them into several varieties—as onyx, agate, dotted agate, &c.
Subs. 6.—Hornstone.
In nodular or angular masses, imbedded in the secondary limestone of the west shores of Green Bay; and in the beds of argillaceous white clay strata of Cape Girardeau, of Missouri. Also, on the hills of White River, Arkansas.
Subs. 7.—Jasper.
1. Common Jasper.—In detached fragments, yellow, in the drift of Lake Superior.
2. Striped Jasper.—With the preceding. Most commonly, these specimens consist of alternate bands of red and black, or brown.
3. Red Jasper.—In quartz rock, Sugar Island, River St. Mary’s, Michigan. Masses of this mineral have been met in situ.
Subs. 8.—Heliotrope.
A fine specimen of this mineral, now before me, was procured at the mouth of the Columbia River, Oregon. It is in the form of an Indian dart. Its color is a deep uniform green, variegated with small spots of red; those parts which are green being fully translucent, the others less so, or nearly opaque. This beautiful mineral is represented to have been in common use by the Indian tribes of the Northwest Coast, for pointing their arrows, previous to the introduction of iron among them. It differs chiefly from the dotted jaspers of Lake Michigan, in its translucence and green color.
Subs. 9.—Opal.
Common opal occurs as a constituent of agate, along with chalcedony rarely, in the drift on the south shore of Lake Superior.
2. Silicious Slate.
1. Common.—In subordinate beds, in the argillite of the River St. Louis, northwest of Lake Superior.
2. Basanite (Touchstone).—In detached fragments in the drift on Lake Superior, and along the banks of the Upper Mississippi generally.
3. Petrosilex.
In large isolated masses in the bed of the Illinois River, on the shallow rapids between the junction of the Fox and Vermilion Rivers. It is mostly arranged in stripes or circles of white, gray, yellow, &c., resembling certain jaspers, or approaching sometimes to hornstone. The bed of the Illinois River, at this place, is a species of gray sandstone. Also, in detached fragments, on the south shore of Lake Superior, intimately mixed with prehnite. In regard to the latter, Professor Dewey, of Williamstown College, writes me: “I have received from Dr. Torrey, a curious mixture of petrosilex and prehnite, in imperfect radiating crystals, which was sent him by you and collected at the West. He did not tell me the name, but examination showed what it was. The association is singularly curious.” The locality of this mineral is Keweena Point, Lake Superior.
4. Mica.
Occurs rarely in the granite of Lake Superior. It is found in place on the Huron Islands. Also, in minute folia, in the alluvial soil of the Upper Mississippi. A beautiful aggregate, consisting of plates of gold-yellow mica, connected with very black and shining crystals of schorl, has been dug up from the alluvial soil of the Island of Michilimackinac.
5. Schorl.
1. Common Schorl.—In crystals, in boulders of granite, at Green Bay.
2. Tourmaline.—With the preceding.
6. Feldspar.
As an ingredient in the granite of Huron Islands, Lake Superior. Also, in detached masses of granite along the west shores of Lake Michigan. Also, in the form of prismatic crystals of a light-green color, in the rolled masses of hornblende, porphyry, greenstone, and epidotic boulders of Lakes Huron, Michigan, and Superior.
7. Prehnite.
This mineral occurs at Keweena Point, on Lake Superior. It is found in connection with isolated blocks of amygdaloid, of primitive greenstone, and of petrosilex. Sometimes native copper, and carbonate of copper, are also present in the same specimen. In some instances, a partial decomposition has taken place, converting its green color into greenish-white, or perfect white, and rendering it so soft as to be cut with a knife. Sometimes the grains or masses of native copper are interspersed among the prehnite, and slender threads of this metal occasionally pass through the aggregated mass of greenstone, prehnite, &c., so that, on breaking it, the fragments are still held together by these metallic fibres.
8. Hornblende.
1. Common Hornblende.—Occurs as a constituent of the hornblende rocks near Point Chegoimegon, Lake Superior. Also, at the Peace Rock, on the Upper Mississippi, and in certain granite aggregates, and rolled masses of porphyries, &c., around the shores of Lakes Huron, Michigan, and Superior.
2. Actynolite.—In slender, translucent, greenish crystals, pervading rolled masses of serpentine, on the west shores of Lake Michigan.
9. Woodstone.
1. Mineralized Wood.—In bed of the River Des Plaines, Illinois.
2. Agatized Wood.—This variety of fossil wood is found along the alluvial shores of the Mississippi and of the Missouri.
c. Calcareous Minerals.
Carbonate of Lime.
Of a substance so universally distributed throughout the western country, it will not be necessary to give many localities, and these will be principally confined to its crystalline forms.
Subs. 1.—Calcareous Spar.
Crystallized Calcareous Spar.—This mineral occurs, in minute rhomboidal crystals, in the calcareous rock of the Island of Michilimackinac. Sometimes these crystals fill cavities or seams of the rock, or are studded over the angular surfaces of masses of vesicular limestone of that island. I also found this mineral at Dubuque’s mines, and in small crystals in the metalliferous limestone bordering the Fox River, between the post of Green Bay and Winnebago Lake, where it is associated with iron pyrites and blende.
Subs. 2.—Compact Limestone.
In proceeding northwest of Detroit, this mineral is first observed, in situ, on an island in Lake Huron. It is afterwards found to be the prevailing rock along the south and southwest shores of Lake Huron. In many places, it incloses fossil remains. Sometimes it is earthy, as at Bay De Noquet, a part of Green Bay, on Lake Michigan, where it contains very perfect remains of the terrebratula. (Parkinson.) In other places, no remains whatever are visible, and the structure is firm and compact; or even passes, by a further graduation, into transition-granular, of which, it is believed, the west shores of Lake Michigan afford an instance. It is most commonly based upon sandstone, which also contains, in many places, the fossil organized remains of various species of crustaceous animals, and of vegetables, sometimes, coal, &c.
Subs. 3.—Agaric Mineral.
This mineral substance occurs in crevices and cavities in the calcareous rock of the Island of Michilimackinac, Michigan.
Subs. 4.—Concrete Carbonate of Lime.
1. Calcareous Sinter.—In the form of stalactites and stalagmites, in a cave situated near Prairie du Chien, on the Upper Mississippi.
2. Calcareous Tufa.—A remarkable formation of tufa is seen on the east banks of the Wabash River, near Wynemac’s Village, about ten miles above the junction of the Tippecanoe. It extends for several miles, and is deposited to the thickness of thirty or forty feet above the water, forming cliffs which are covered with alluvial soil and sustain a growth of forest trees. The precise points of its commencement and disappearance were not observed. The structure is cellular or vesicular, and resembles, in some places, a coarse dried mortar. It is very light, and possesses a white color in inferior situations, but the surface is somewhat colored by fallen leaves and other decaying vegetation. It imbeds fluvatile shells and some vegetable remains, the species of which have not been ascertained. The opposite, or west side of the river consists of a kind of puddingstone, or caschalo, made up of pebbles of quartz, &c., cemented by carbonate of lime, of a yellow color and translucent. This beautiful aggregate is overlayed by a stratum, of fifteen or twenty feet in thickness, of diluvial soil. These localities fall within the limits of the State of Indiana; but on territories still occupied, if not owned, by the aborigines.
3. Pseudomorphous Carbonate of Lime.—This form of carbonate of lime occurs in Pope County, Illinois, a district celebrated for its fluorspar, lead, crystallized quartz, &c., and bearing the unequivocal marks of a secondary formation. Scattered in large masses over the soil, we observe compact limestone, with very perfect cubical, octahedral, or other regular cavities, which have manifestly originated from crystals of fluorspar. The most common impress of this kind appears to have resulted from two cubes variously joined—a form of appearance very common to the Illinois fluates. Some of these cubical cavities exceed three inches square; but in no case is any remaining portion of the spar in these cavities, or anywise connected with the fragments of limestone thus impressed, although, at the same time, the spar is very abundant in the alluvial soil where these curious limestones are found.
2. Sulphate of Lime.
Subs. Gypsum.
1. Fibrous Gypsum.—In the alluvial soil of the St. Martin’s Islands, Lake Huron. The fibres are sometimes five or six inches in length, of a white color and delicate crystalline lustre. Sometimes these fibrous masses are partially colored yellow or brown, apparently from the clay, or mixed alluvion, in which they are imbedded.
2. Granular Gypsum.
3. Granularly-Foliated Gypsum.
4. Earthy Gypsum.
}With the preceding.
3. Fluate of Lime.
Fluor-Spar.—On the United States Mineral Reserve, Pope County, Illinois. This locality is abundant, and the mineral readily and constantly to be obtained. I first obtained specimens in June, 1818, and afterwards visited it in July, 1821. It is disseminated in loose masses throughout the soil, and in veins in the calcareous rocks. The spot most noted and resorted to, and where the original discovery was made, is four miles west of Barker’s Ferry, at Cave-in-Rock, on the banks of the Ohio, and about twenty-six miles, by the course of the river, below Shawneetown. It is situated in the midst of a hilly, broken region, called the Knobs, a tract of highlands intervening between the banks of the Ohio and the Saline. The distance of this range from north to south, or parallel with the course of the Ohio, cannot be stated. It probably extends from near the banks of the Wabash River to the Little Chain of Rocks. Its breadth—from Barker’s Ferry, west, to Ensminger’s, at the Saline, is about twenty miles. It thus separates, by a rocky border, the prairies of the Illinois from the current of the Ohio River. These knobs, wherever observed, bear the indubitable marks of secondary formation, and may be stated to consist, essentially, of compact limestone resting on sandstone. The sandstone is sometimes so much colored by iron, and by globular or irregular masses of iron stone, as to give that rock a very singular aspect. This may be particularly instanced in the mural front of the Battery rocks on the banks of the Ohio. Every part of this formation has more or less the appearance of a mineral country; and it is already known as the locality of ores of lead, iron, and zinc, of crystallized quartz, of opal, heavy spar, crystallized pyrites, and of very perfect fossil madrepores. In one place (near the head of Hurricane Island) this spar forms a very large and compact vein, dipping under the bed of the Ohio. Where the rock has been explored, it is found in connection with sulphuret of lead, but it has been mostly procured, because most easy of access, in the alluvial soil. I went out about half a mile west of the Ohio, where a new locality has been opened, and, in removing about five or six solid feet of earth, procured as many specimens as filled a box of fourteen inches square. None of these were more than two feet below the surface. One of these specimens is an irregular octahedral crystal, eight inches in diameter. The color of these masses is various shades of blue, violet, or red, sometimes perfectly white or yellow; and the form most commonly assumed is a cube, sometimes truncated at two or more angles, or variously clustered. The external lustre of the crystals, raised from alluvial soil, is feeble, but quite brilliant when taken from veins and cavities in the rock. These spars from the alluvion do not appear to exist as rock debris, or fragments worn off from other formations, but as original deposits. There are no marks of attrition. They appear as much in place as the limestone rocks below. It should also be recollected that this mineral tract is terminated by one of the greatest and most valuable salt formations in the western country—that of the Illinois Saline.
Septaria: Ludus Helmontii.—This variety of calcareous marl is found, in orbicular or flattened masses, along the eastern shores of Lake Michigan, between the rivers St. Joseph’s and Kalemazo. Its original situation appears to be the beds of marly clay which form the banks of Lake Michigan at these places, from which these masses have been disengaged by the waves, and left promiscuously among the washed and eroded debris of the shore. These masses are penetrated by numerous seams and lines of calcareous spar, sometimes radiating star-like, or intersecting each other irregularly. Occasionally, these seams are filled with sulphuret of zinc, and in these cases the spar, if any be present, is rose-colored.
d. Aluminous Minerals.
Argillaceous Slate.
1. Argillite, or Common Argillaceous Slate.—Along the banks of the River St. Louis, at the Grand Portage, &c. It occurs in a vertical position, embracing veins, or subordinate beds, of grauwakke, milky quartz, chlorite slate, and silicious slate, &c. It is bounded on one side by red sandstone, and on the other by an extensive tract of diluvial soil.
2. Bituminous Shale.—In detached masses, along the shores of Lake Huron, between Fort Gratiot and Thunder Bay. It contains amorphous masses of iron pyrites, of a yellow color and metallic brilliancy, which soon tarnishes on exposure to the air.
2. Chlorite.
Chlorite Slate.—In subordinate strata in the argillite of the River St. Louis.
3. Staurotide.
In garnet-colored crystals, in detached blocks of mica-slate, in the drift of Lake Huron. These crystals consist of two intersecting six-sided prisms, truncated at both ends, forming the cross. They are nearly opaque, or feebly translucent on the fractured edge.
4. Clay.
1. Plastic Clay.—Very extensive beds of this clay are seen along the west shore of Lake Michigan, between Sturgeon Bay Portage and Chicago. Its color is generally a light blue, verging sometimes into deep blue or grayish-white. It is plastic in water, adheres strongly to the tongue, takes a polish from the nail, and emits an argillaceous odor when moistened or breathed upon. These beds of clay frequently contain iron pyrites, both in the crystallized and amorphous state.
2. Pipe Clay.—In the flats of the St. Clair and Lake George, Michigan. A bed of clay, apparently answering to this description, exists at White River, Lake Michigan. Its color is a grayish-white, verging to blue. It is very unctuous and adhesive when first raised, but acquires more or less of a meagre feel as it parts with its moisture, drying in firm and compact masses.
3. Variegated Clay.—On the banks of the River St. Peter’s, Upper Mississippi. Neither the quantity in which it exists, nor the precise locality is known. Its color is white, variegated with stripes, spots, or clouds of red or yellow.
4. Azure Blue Clay of St. Peter’s.—The locality of this substance, as communicated by the Indians, is the declivity of a hill, in the rear of the village of Sessitongs, one mile above the confluence of the Terre Blue River with the St. Peter’s. It is found near the foot of this hill, between two layers of sandstone rock, in a vein about fifteen inches in thickness. This vein is elevated about twenty feet above the waters of the Terre Bleu, and does not extend far in the direction of the river. Having been resorted to by the Sioux Indians a long time, a considerable excavation has been made, but the supply is constant. The color of this mineral substance (its distinguishing character) is an azure copper blue of more or less intensity. It is ductile and moderately adhesive, when first taken up, or when moistened with water, but acquires an almost stony solidity on drying. It is considerably adulterated with sand or particles of quartz. It parts with its moisture rapidly on exposure to the atmosphere, and dries without much apparent diminution of volume.
5. Green Clay of St. Peter’s.—This differs little from the preceding, except in its color, which is a deep or verdigris green, admitting some diversity of shades. Its composition appears to be, essentially, alumina, silica, carbonate of copper, water, and iron.
6. Opwagunite; Calamet Stone; Pipe Stone.—The last of these terms is a translation of the first, which is Algonquin. Under these names, a peculiar kind of stone, which is much employed by the Indians for pipes, has been alluded to by travellers and geographers from the earliest times. It appears to be a variety of argillaceous wacke. Its color is most commonly a uniform dull red, resembling that of red chalk. Sometimes it is spotted with brown or yellow, but these spots are very minute, and the colors usually faint. It is perfectly opaque, very compact in its structure, and possessing that degree of hardness which admits its being cut or scraped with a knife, or sawed without injury to a common hand-saw, when first raised from the quarry; but it acquires hardness by exposure, and even takes a polish. But it is not capable of receiving a polish by the usual process of rubbing with grit-stone and pumice, these substances being too harsh for it. The Indian process is to scrape or file it smooth, and give it a polish by rubbing with the scouring rush. Its powder is a light red, and emits an argillaceous odor when wetted. This substance is procured at the Coteau des Prairie, intermediate between the sources of the St. Peter’s and the Great Sioux Rivers. Some other places have been mentioned as affording this mineral, particularly a locality on the waters of Chippewa River; but the mineral procured here is chocolate-colored.
e. Magnesian Minerals.
1. Serpentine.
At Presque Isle Point, Lake Superior, common and precious, in isolated masses; also, in connection with, and imbedding native copper, along the southern shore of Lake Superior, at Ontonagon River, &c.
2. Steatite.
At Presque Isle, near River au Mort, Lake Superior, in connection with the serpentine formation. Also, at the Lake of the Woods, of a black or very dark color, where it is employed by the Indians in carving pipes.
3. Asbestos.
Common Asbestos.—In serpentine and steatite, at Presque Isle Point, Lake Superior. Also, in minute veins, in detached masses of diallage and serpentine rocks, on the west shore of Lake Michigan. These veins are no more than a fourth of an inch in width; and the fibres of asbestos occur transversely. They are very flexible, and easily reducible into a flocculent mass.
f. Barytic Minerals.
Sulphate of Barytes.
Lamellar Sulphate of Barytes.—In detached masses, imbedded in diluvial soil, at the mines of Peosta, or Dubuque, on the Upper Mississippi, where it is accompanied by sulphuret of lead, calcareous spar, &c. Also, at the Mine au Fevre (now Galena), and at the mouth of the Sissinaway River, on the east banks of the Mississippi, between Prairie du Chien and Fort Armstrong. Its colors are white or yellow, and it is frequently incrusted with a thin coat of yellow oxide of iron. It is most commonly opaque. The only translucent specimen seen was procured at Dubuque’s mines.
g. Strontian Minerals.
Sulphate of Strontian.
Foliated Sulphate of Strontian.—At Presque Isle (Wayne’s Battle Ground), on the Maumee River, Wood County, Ohio. It occurs in veins and cavities, in compact limestone, most commonly in the form of flattened prisms. Its color is blue, frequently a very light or sky-blue, and the crystals are fully translucent, or even transparent. In some instances, they appear to have suffered a partial decomposition, and fall into fragments in the act of raising, or are covered with a white powdery crust, frequently visible only on the summits or terminating points of the prisms. The same limestone yields crystallized calcareous spar. Both these substances are abundant in the rocky banks and in the bed of the Maumee. Also, on Grosse Isle, Detroit River, Michigan.
h. Bituminous Minerals.
1. Bitumen.
Petroleum.—Occurs in cavities, in loose fragments of limestone rock, along the west shore of Lake Michigan, between Milwaukie and Chicago. These masses of rock lie promiscuously among fragments of quartz, granite, sandstone, fossil madrepores, &c., along the alluvial shore of the lake, and appear to have been washed up from its bed. The petroleum is in a free and liquid state; but, where it has suffered an exposure to the atmosphere, it has acquired a stiff and tar-like consistence passing into maltha. Not unfrequently, fragments of mineral coal are also found scattered along these shores, and there is reason to conclude that a bituminous formation exists in the contiguous inferior strata forming the basin of the lake.
2. Graphite.
Granular Graphite.—In a small vein, in the clay-slate of the River St. Louis, at the head of the nine-mile portage. It is coarse-grained and gritty.
3. Coal.
Slaty Coal.—The only spot where this mineral has been observed, in situ, is at La Charbonniére, on the west banks of the Illinois River, at the computed distance of one hundred and twenty miles south of the post of Chicago. It is here seen in horizontal strata, not exceeding two or three inches in thickness, interposed between layers of sandstone and shale. Breaking out on the declivity of the bank of the river, where the overlaying strata are constantly crumbling down, and thus obscuring the seams, no very satisfactory examination could be made in a hasty visit; but the nature and position of the rock strata and soils, and the general aspect of the country, do not justify the conclusion that the bed is of much thickness or extent. Valuable beds may be discovered, however, by exploring this formation. This coal has a shining black color, a slaty structure, inflames readily, burning with a bright flame. It is very fragile where exposed to the weather, falling into fine fragments. Hence, a very black color has been communicated to the contiguous and overlaying soil, which is manifestly more or less the result of disintegrated coal.
Detached fragments of coal, corresponding in mineral characters with the above, are occasionally found around the southern shores of Lake Michigan. The inference, as to the existence of coal around the shores of this lake, is obvious. And we are led to inquire: Does the La Charbonniére formation of coal exist in the sandstone and limestone strata forming the table-land between the Illinois River and Lake Michigan, and reappearing around the basin of the latter, but at such a depression below its surface as to elude observation? And, if so, does not this coal formation extend quite across the southern portion of the peninsula of Michigan? The secondary character of the region alluded to, so far as observed, the horizontal and relative position of the strata, and the general uniformity which is generally observed in the species and order of the coal measures, favor this suggestion.
i. Soda.
1. Muriate of Soda.
No traces of salt are known to have been discovered in those parts of the territory of the United States situated north of latitude 46° 31´ (which is that of the Sault Ste. Marie) and east of the Mississippi River. The great secondary formations which pervade the western country cease south of this general limit, and with them terminate the salt springs, the gypsum beds, the coal measures, and other connected minerals which are generally found in association. It is one of the most important facts which the science of geology has contributed to the stock of useful information, that, in the natural order of the rocky and earthy deposits, muriate of soda always occupies a position contiguous to that of gypsum. This intimate connection between the sulphate of lime and the muriate of soda, enables us, by the discovery of the one, to predict, with considerable but not unerring certainty, the presence of the other. It adds weight to an observation first made among the salt formations of Europe, to find its general correctness corroborated by the relative position of these substances in the United States. These remarks will apply particularly to the salt formations of New York, and to some portions of the muriatiferous region of Virginia and the Arkansas.
There appears to be a salt formation extending from the northwest angle of the Ohio through Michigan, for a distance of two hundred to three hundred miles. It commences in the Seweekly country, passing around the Sandusky River of Lake Erie, where an extensive bed of granular gypsum has recently been discovered, and continues, probably, northwest, so as to embrace the Saganaw basin, and reach quite to the end of the peninsula, and embracing, perhaps, the Gypsum Islands of Lake Huron, ten miles northeast of Michilimackinac. All the brine springs and gypsum beds noticed in the region are situated in the line of this formation.
During the fall of 1821, a number of gentlemen at the Island of Michilimackinac united in the expenses of a tour for exploring the Skeboigon River, a stream which originates in the peninsula of Michigan, and flows into Lake Huron opposite the Island of Bois Blanc. The particular object of this party was to ascertain the precise locality of certain salt springs reported to exist upon that stream. They proceeded to the places indicated, and examined several springs more or less impregnated with salt, but reported that, owing to the jealousy and hostility of those bands of Indians who were found upon that stream, they were not enabled fully to accomplish the object in view.
There are several salt springs reported to exist near the Indian village of Wendagon, on the Sciawassa River, and others on the Titabawassa River, the principal tributaries of the Sagana. Little is, however, known respecting these springs, but the water is represented to be so strongly impregnated, that the Indians manufacture from it all the salt necessary for their villages.
Grand River Valley has also been mentioned among the localities of salt water and gypsum rocks.
Hints may thus be derived of value to the future commerce of the country. Scarcely any of the new states are without indications of the existence of salt. Every day is adding to the number of localities.
In the region west of the Mississippi, I was informed that salt occurs, in the crystallized form, in the territories of the Yanktons, who inhabit the flat country at the sources of the River St. Peter’s. In certain parts of these plains, the salt exists on the surface. It is mixed with earth, in specimens brought to me, but crystallized in cubes, very imperfect, of a gray or grayish-white color. The Indians scrape it up from certain parts of the prairies or plains, where the salt water is prevented from draining off.
2. Alkaline Sulphate of Alumina.
This salt exists, in the form of efflorescences, in the cavities and fissures of rocks along the southeast parts of the shores of Sagana Bay, Lake Huron, and in the argillaceous formations at Erie, on Lake Erie, Pennsylvania.
These positions embrace the principal localities of minerals noticed. In travelling rapidly through a remote wilderness, there was but little opportunity to explore off the track; and the whole observation was confined to the mere surface of the country, which is much obscured by diluvial and alluvial formations.
It will be seen that the region of Lake Superior has been a fruitful field for mineralogical inquiry, and it is one which invites further exploration. Its mineralogy affords a variety of interesting substances which are objects of scientific research, and it may be anticipated to be the future theatre of extensive mining operations. The country northwest of Lake Superior, and the Upper Mississippi north of the Falls of St. Anthony—consisting mostly of upheaved primitive rocks and the pebble-drift, or diluvial, formations—has furnished but few subjects of mineralogical remark.
The district of country between the Falls of St. Anthony and Prairie du Chien, in common with the more southern portions of the Mississippi Valley, partakes of all the interest which the mineral kingdom presents in a calcareous and metalliferous country of secondary formation. It has added considerably to my collection. It is probable the Rivers St. Peter’s, St. Croix, and Chippeway would well reward exploration; but the mines of Dubuque particularly invite a mineralogical survey. Their future importance cannot fail to be duly appreciated.
If the country has put on an aspect unfavorable to mineralogy, its geological features have been observed to sustain its interest.
Much of the interest growing out of the examination, for the first time, of the mineralogy and natural history of the country, is such as to commend itself, in an especial manner, to the consideration of men of science, and of associations devoted to scientific details, rather than the department of a government. To these former, nature is a storehouse of facts, and a perpetual anxiety is felt by this class of observers to know the range, not only of our rock formations, but of our plants, shells, fossils, and other classes of objects in our physical geography. Such desires I have endeavored, as far as my means permitted, to gratify. The fresh-water conchology of the lakes and rivers visited was often attractive, when other objects excited little interest. The species collected in this department have been referred to the New York Lyceum of Natural History.
With these remarks, the result of an arduous and interesting journey through a part of the continent hitherto unexplored, I have the honor to conclude my report, and to terminate the trust confided to me.
I am, sir, with respect,
Your obedient servant,
HENRY R. SCHOOLCRAFT,
Geologist, &c. of the Ex. Exp.
VIII. (A.)
A Report to the Senate of the United States, in Answer to a Resolution passed by this Body, respecting the Value and Extent of the Mineral Lands on Lake Superior.235 By Henry R. Schoolcraft.
Sault Ste. Marie, October 1, 1822.
Sir: In reply to the inquiries, contained in a resolution of the Senate of the United States, respecting the existence of copper mines in the region of Lake Superior, inclosed to me in a note from the War Department, dated 8th May, 1822, I have the honor to submit to you the following facts and remarks:—
1. In relation to “the number, value, and position of the copper mines on the south shore of Lake Superior.” The remote position of the country alluded to, the infrequency of communication, and the little reliance to be placed on information derived through the medium of the aborigines or of traders, who are wholly engrossed with other objects, presents an embarrassment at the threshold of this inquiry, which must be felt by every person who turns his attention to the subject. The information sought for demands a minute acquaintance with the natural features and mineral structure of the country, which can only be acquired by personal examination; and it is a species of research requiring more leisure, better opportunities, and a freer participation in personal fatigue, than usually falls to the share of tourists and travellers. Not only are those difficulties to be encountered which are inseparable from the collection of isolated facts in a new and unsettled country, but those, also, which are peculiar to the subject, connected as it is, at every stage of the inquiry, with the prejudices and superstitions of the Indian tribes. [B.] It can, therefore, excite little surprise that, after having been the theme of speculation for more than a century, and obtained the notice of several works of merit in Europe,236 both the position and value of these mineral beds have continued to the present times to be but partially known. To ascertain more clearly their value and importance to the Republic were objects more particularly confided to me as a member of the expedition sent by the Indian Department, in the year 1820, to traverse and explore those regions. My report of the 6th of November of that year—a copy of which, marked A, is herewith transmitted—gives the result of that inquiry. After a lapse of two years, little can be added. Reflection and subsequent inquiry convince me that the facts advanced in that report will be corroborated by future observation. No circumstance has transpired which is calculated to prove that my suggestions with regard to the fertility and future importance of those mines are fallacious; on the contrary, all information tends to strengthen and confirm those suggestions. Specimens of pure and malleable copper continue to be brought in to me by the aborigines from that region, but it is not deemed necessary to particularize in this place the additional localities. It will be sufficient to observe, that the number of these new discoveries justifies the expectations that have been created respecting the metalliferous character of the region of the Ontonagon, and the south shore of Lake Superior. [C.]
I shall here add the result of an accurate analysis made upon a specimen of this copper at the mint of Utrecht, in the Netherlands, at the request of Mr. Eustis, minister plenipotentiary from the United States, who carried samples of the American copper to that country. The report of the inspector of the mint, which communicates the result of this analysis, has the following remarks upon the natural properties of this species of copper, and the mode of its production: “From every appearance, the piece of copper seems to have been taken from a mass that has undergone fusion. The melting was, however, not an operation of art, but a natural effect caused by a volcanic eruption. The stream of lava probably carried along in its course the aforesaid body of copper, that had formed into one collection, as fast as it was heated enough to run, from all parts of the mine. The united mass was probably borne in this manner to the place where it now rests in the soil. The crystallized form, observable everywhere on the original surface of the metal that has been left untouched or undisturbed, leads me to presume that the fusion it has sustained was by a process of nature; since this crystallized surface can only be supposed to have been produced by a slow and gradual cooling, whereby the copper assumed regular figures as its heat passed into other substances, and the metal itself lay exposed to the air.
“As to the properties of the copper itself, it may be observed that its color is a clear red; that it is peculiarly qualified for rolling and forging; and that its excellence is indicated by its resemblance to the copper usually employed by the English for plating. The dealers in copper call this sort Peruvian copper to distinguish it from that of Sweden, which is much less malleable. The specimen under consideration is incomparably better than Swedish copper, as well on account of its brilliant color as for the fineness of its pores and its extreme ductility. Notwithstanding, before it is used in manufactures, or for the coining of money, it ought to be melted anew, for the purpose of purifying it from such earthy particles as it may contain. The examination of the North American copper, in the sample received from his excellency the minister, by the operation of the cupel and test by fire, has proved that it does not contain the smallest particle of silver, gold, or any other metal.” It is a coincidence worthy of remark, that the suggestions offered by the assayer respecting the volcanic origin of these masses of copper, are justified by the leading features of the Porcupine Mountains, and by the melted granites found upon the heights called Grande Sables and Ishpotonga.
2. The second and third inquiries of the resolution relate to “the names of the Indian tribes who claim the mines, and the practicability of extinguishing their title.” By the treaty concluded at this post on the 16th of June, 1820, the Ojibwai237 Indians cede to the United States four miles square of territory, bounded by the River St. Mary’s, and including the portage around the falls.238 This is the most northerly point to which the Indian title has been extinguished in the United States. The different bands of Ojibwais possess all the country northwest of this post, extending through Lake Superior to the sources of the Mississippi, where they are bounded by the Assennaboins, the Crees, and the Chippewyans of the Hudson Bay colony. Their lands extend down the Mississippi to the Sioux boundary, an unsettled line between the junction of the River De Corbeau and the Falls of St. Anthony. South of Lake Superior, they claim to the possessions of the Winnebagoes, on the Ouisconsin and Fox Rivers, and to those of the Pottawatamies and Ottoways, on Lake Michigan. The Wild Rice, or Monomonee Indians, are an integral part of the Ojibwai nation, deriving their name from the great reliance they place on the zizania aquatica as an article of food. They live in small, dispersed bands between the Ojibwais of the lake, and the Winnebagoes of Fox River. Those residing among the Ojibwais speak the same language, but with many peculiarities and corruptions on the waters of Green Bay. They claim the respective tracts upon which they are located. These are, principally, the valleys of the Fox and Monomonee Rivers, and the rice lands contiguous to the Fol. Avoine, Clam Lake, and Lac de Flambeau, which lie on the table-lands between Lake Superior and the Mississippi.
The right of soil to all that part of the Peninsula of Michigan not purchased by the United States is divided between the Ojibwais and the Ottoways. The former claim all the shores and islands of Lake Huron situated north of the Saganaw purchase, except those in the vicinity of Michilimackinac and the St. Martin, or Gypsum Islands, which were ceded by treaty on the 6th of July, 1820.239 Their territories continue north, through the River St. Mary’s, embracing the country on both banks, and the islands in the river, saving Drummond’s Island, which is garrisoned by the British, and the Four Mile concession at the Sault or Falls, now occupied by a detachment of the United States’ army. It is not deemed necessary to point out the limits of their territories with more precision, or to pursue them into the Canadas, where they are also very extensive. It will sufficiently appear, from this outline, that the discoveries of copper on the south shore of Lake Superior are upon their lands. That some of these discoveries have been made upon, or will be traced to, the possessions of the North Monomonees, is also probable.
With respect to the practicability of extinguishing the Indian title, no difficulty is to be apprehended. Living in small villages, or tribes of the same mark, scattered over an immense territory, and often reduced to great poverty by the failure of game and fish, it is presumed there would be a disposition among their chiefs and head men to dispose of portions of it. Those districts which most abound in minerals, presenting a rough and rocky surface, are the least valuable to them as hunting-grounds; and the goods and annuities which they would receive in exchange must be vastly more important to them than any game which these mineral lands now afford.
3. “The probable advantage which may result to the Republic from the acquisition and working of these mines.” How far metallic mines, situated upon the public domain, may be considered as a source of national wealth, and what system of management is best calculated to produce the greatest advantages to the public revenue, are inquiries which are not conceived to be presented for consideration in this place; nor should I presume to offer any speculations upon topics which have been so often discussed, and so fully settled. In applying axioms, however, to a species of productive industry, the results of which are so very various under various situations, great caution is undoubtedly necessary; and it must appear manifest, on the slightest reflection, how much the comparative value of metallic mines, equally fertile and productive, ever depends upon situation and local advantages. Dismissing, therefore, all questions of abstract policy, I shall here adduce a few facts in relation to the fertility of these mineral beds, and their position with respect to a market—points upon which their value to the nation must ultimately turn.
That copper is abundantly found on the south shore of Lake Superior has been shown. It is unnecessary here to add to, or repeat the instances of its occurrence, or to urge, from an inspection of the surface, the fertility of subterranean beds. All the facts which I possess in relation to this subject are before you, and you will assign to them such importance as they merit. It is a subject upon which I have bestowed some reflection and much inquiry, superadded to limited opportunities of personal observation, and the result has led me to form a favorable estimate of their value and importance. It is not only certain that a prodigious number of masses of metallic copper are found along the borders of the lake, but every appearance authorizes a conclusion that they are only the indications of near and continuous veins. Some of these masses are of unexampled size, and all present metallic copper in a state of great purity and fineness. Of its ductile and excellent qualities for the purposes of coinage and sheathing, the analysis of Utrecht leaves no doubt. It is true that a mistaken idea has prevailed among travellers and geographers respecting the weight of the great mass of copper on the Ontonagon River; but it is, nevertheless, of extraordinary dimensions, and I have endeavored to show, from their works, how these errors have originated, and that the metal is disseminated throughout a much greater extent of country, and in masses of every possible form and size. Until my facts and data can, therefore, be proved to be fallacious, I must be permitted to consider these mines not only fertile in native copper and its congenerous species, but unparalleled in extent, and to recommend them as such to the notice of the Government.
But, whatever degree of incertitude may exist respecting the riches of these mines, their situation with respect to a market can admit of no dispute. As little can there be concerning the advantages which this situation presents for the purposes of mining and commerce. Let us compare it with that of other mines, and appeal to acknowledged facts for the decision. The value of a coal mine, a stone quarry, or a gypsum bed, often arises as much from its situation as its fertility. But the proposition may be reversed with respect to a metallic mine, the value of which to the proprietor arises more from its fertility and less from its situation. Gold, silver, copper, tin, lead, &c., when separated from the matrix of the mine, are so valuable that they can bear to be transported a long journey over land, and the most distant voyage by water. Their worth in coined money, produce, or manufactures, is not fixed in the particular circles of country where they are dug up, but depends upon the seaboard market, and embraces all countries. The silver of Mexico and Peru circulates throughout Europe, and is carried to China. It is no objection to those mines that they are situated in the Cordilleras, or upon the high table-lands of the American continent, and must be carried a thousand miles upon the backs of mules to the seaside. The very discovery of those mines has rendered many poor silver mines of Europe of no value, although possibly situated in the environs of the best silver markets in the world. It is the fertility, and not the situation of such mines, that constitutes their chief value; and it is so with many of the coarser metals.
The tin of the Island of Banka, and the Peninsula of Siam in Asia, and the copper of Japan, find their way to Europe, and are articles of commerce in the United States. The cobalt of Saxony is sent to Pekin, and the platina of Choco, to all parts of the world. In all these instances, the fertility of the mines compensates for every disadvantage of situation. But this principle is not alone confined to mines of tin, copper, &c.; it even holds true of the heavy and bulky articles of iron, lead, and salt. The lead of Missouri finds a market at New York, Philadelphia, and Boston, and will be carried to Europe. It is no objection that it must be conveyed in wagons forty miles from the interior, and sent a voyage of 3,000 miles in steamboats and merchant ships. The great fertility of the mines counterbalances the disadvantages of its remote position from the market, and it is the price of the metal in the market which always regulates its price at the mines. The malleable iron of Sweden is consumed on the summits of the Alleghany, although its strata are replete with iron ore, which is worked at numerous forges along the rivers which proceed from each side of it. It is believed that the salt springs of Onondaga, from their copiousness alone, would supply a vast portion of the interior and seaboard of the United States with salt, even if the facilities of water carriage had not been presented by the Erie Canal. The value of such mines and minerals ever depends as much upon the abundance as upon the favorable position of them. It is far otherwise with quarries of stone, gypsum, marl, fossil coal, &c., whose contiguity to a good market establishes their value. No abundance of these articles would justify a land carriage of one hundred miles. They constitute a species of mining, the profits and value of which increases in the ratio of the surrounding population, and as the country advances in improvements. But this advantage is far less sensibly felt, and cannot be considered essential to the successful working of mines of silver, copper, &c. Neither the remote position, therefore, of the Lake Superior copper mines, nor the want of a surrounding population, present objections of that force which would at first seem to exist; and it is confidently believed that, if their fertility is such as facts indicate, they may be opened and wrought with eminent advantage to the Republic. But let us examine their situation with respect to a market, and compare it with that of other mines of the same metal, and of some of the coarser metals, which bear a considerable land, and the most distant water carriage. To favor the inquiry, let it be granted for the moment that proximity of situation to a market, or free water carriage, are indispensable to the success and value of the most fertile mines.
Assuming the confluence of the Ontonagon River with Lake Superior (which is apparently the centre of the mine district) as the place where the metal is first to be embarked for market, it must be carried down the lake 300 miles to the Sault or rapids of St. Mary’s. Here, if it is in barges, it may descend the rapids in perfect safety, as is the invariable practice of the traders on arriving with their annual returns of furs and skins from the north. If in vessels, it must be transferred either into boats or carts, and carried half a mile to the foot of the rapids, where it will again be embarked in vessels, and transported through the Lakes Huron, St. Clair, and Erie, and their connecting straits, to Buffalo, a distance of 650 miles. The progress made in the construction of the great canal which is to connect the lakes and Atlantic, is such as to leave no doubt upon any reasonable mind of the full completion of that work with the close of the year 1824. Through this channel, the transportation is to be continued in boats or barges, by a voyage of 353 miles, to the Hudson at Albany; thence a sloop navigation of 144 miles, which, for speed and freedom from risk, is perhaps unequalled in all America, takes it into the harbor of New York, making the entire distance, from the mouth of the Ontonagon, 1,447 miles. From New York it is distributed to our naval depots, and to the markets of Europe. It is exchanged for the lead of Missouri, the iron of Sweden, or the silver of Mexico; and the same ready communication transports the return cargo to Buffalo, from whence the commerce is extended, by means of the lakes, throughout western New York, Pennsylvania, Ohio, Indiana, Illinois, Michigan, and the interminable regions of the north. Thus it is seen that, when the Erie Canal is completed, a free and direct water communication, from the mines to one of the best markets in America, will exist, in which the rapids of St. Mary’s are the only interruption, and this is only an interruption to large vessels. Not only so, but the Ontonagon River may be ascended many miles with vessels of light burden, and thus the copper of Lake Superior, wafted from the heart of the interior, and from the base of the Porcupine Mountains, into the harbors of New York, Philadelphia, &c. Of this whole distance, 1,047 miles are now navigated by the largest class of river craft and lake schooners; the balance of the distance is the length of the Erie Canal. (See Note D.)
Let it be recollected that there are no mines of copper situated upon the margin of the sea, and that every quintal of sheet copper, bolts, nails, &c., which we receive from Great Britain, Russia, Sweden, or Japan, is transported a greater or less distance on turnpikes or canals, before it reaches the place of shipment. The richest copper mines of the Russian empire are seated on the summits of the Uralian Mountains; those of Fahlun, in Sweden, and Cornwall, in England, are scarcely more favored as to position; and, owing to a want of coal, all the ores raised at the latter are transported into Wales to be smelted.240 But we need not resort to Europe for instances. All the lead raised at the fertile mines in Missouri is transported an average distance of forty miles in carts and wagons before it reaches the banks of the Mississippi. Steamboats take it to New Orleans, a distance, by the shortest computation, of 1,000 miles. But it must still pass through the Gulf of Mexico, and encounter the perils of the Capes of Florida, and a voyage of 2,000 miles along the coast of the United States, before it reaches its principal marts. The average cost of transporting a hundredweight of lead from Mine au Breton and Potosi to the banks of the Mississippi, during the year 1818, was seventy-five cents. The distance is thirty-six miles. The price of conveying the same quantity from the storehouses at Herculaneum and St. Genevieve to New Orleans, by steamboats, was seventy cents. The distance exceeds 1,000 miles. Hence, it costs more to transport a given quantity thirty-six miles by land than to convey it 1,000 by water. These rates have probably varied since, but the proportionate expense of land carriage, compared to that of water, will remain the same. A quintal of copper may, therefore, be transported from the mines of Superior to Buffalo or Lockport, in New York, for the same sum required to convey an equal quantity of lead from Potosi to St. Genevieve. If we consider the city of New York as the market of both, no hesitancy or doubt can be experienced as to the decided and palpable advantages possessed by the northern mines. It is only necessary to adduce these facts; the conclusions are inevitable. In every point of view, the distance of these mines from the market presents no solid objection to their being explored with profit to the nation.
Pig copper, which is the least valuable form in which this metal is carried to market, is now quoted in the Atlantic cities at 19 cents per pound; sheathing, at 27; brazier’s, at 32. I have no data at hand to show the amount of these articles consumed in the United States, and for which we are annually transmitting immense sums to enrich foreign States. But those who best appreciate the advantages of commerce will readily supply the estimate. It would be an interesting inquiry to ascertain how much of the sums yearly paid for sheathing copper, bolts, nails, engravers’ plates, &c., is contributed to the wealth of the respective foreign States who possess mines of this metal. We can look back to a period in the history of Great Britain, when that power did not contribute one pound of copper to the commerce of Europe. During a period of nine years, closing with the memorable year (in American history) of 1775, the produce of the copper mines of Cornwall was 2,650 tons of fine copper. (See Note E.) Since that time, the yearly returns of those mines exhibit a constant increase; and the copper mines of Great Britain are now the most valuable in the world. The amount produced by the mines of Cornwall and Devon, after deducting the charges of smelting, for the single year of 1810, was 969,376 pounds sterling. (See Note F.) The clear profits of the Dolgoath mine, one of the richest in Cornwall, for a period of five months, during the year 1805, was £18,000, which is at the rate of £43,200, or $192,000, per annum. Next to Great Britain, the most considerable mines of Europe are those of Russia, Austria, Sweden, and Westphalia, as it was in 1808. Of less importance are those of Denmark, France, Saxony, Prussia, and Spain. The proportion in which the British mines exceed those of the most favored European nation is as 200,000 x 67,000. (See Note G.)
There is another consideration connected with this subject which is worthy of remark. Should it be inquired what would be the effects of the purchase of these mines upon the condition of the Indian tribes, the reply is obvious. It would have the most beneficial tendency. They would not only profit by an exchange of their waste lands for goods, implements of husbandry, the stipulated services of blacksmiths, teachers, &c., but the intercourse would have a happy tendency to allay those bitter feelings which, through the instigation of the British authorities in the Canadas, they have manifested, and still continue to feel, in degree, towards the United States. The measures which the President has recently directed to be pursued to assuage these feelings of hostility, and to induce them to cherish proper sentiments of friendship and respect, are already in a train of execution that bids fair for success. Continued exertions, and the necessary and proper means, are all that seem necessary to confirm and complete the effect; and whatever measures have a tendency to increase the intercourse of American citizens with these “remote tribes,” and to give them a true conception of the power and justice, and the pacific and benevolent policy of our Government, must favor and hasten such a result.
I have the honor to be, sir,
With the highest respect,
Your most obedient servant,
HENRY R. SCHOOLCRAFT,
U. S. Indian Agent at the Sault Ste. Marie.
Hon John C. Calhoun,
Secretary of War, Washington.
Notes.
(B.)
Among the numerous superstitions which the Indian tribes entertain, that respecting mines is not the least remarkable. They are firmly impressed with a belief that any information communicated to the whites, disclosing the position of mines or metallic treasures situated upon their grounds, is displeasing to their manitos, and even to the Great Spirit himself, from whom they profess to derive every good and valuable gift; and that this offence never fails to be visited upon them in the loss of property, in the want of success in their customary pursuits or pastimes, in untimely death, or some other singular disaster or untoward event. This opinion, although certainly not a strange one to be cherished by a barbarous people, is, nevertheless, believed to have had its origin in the transactions of an era which is not only very well defined, but must ever remain conspicuous in the history of the discovery and settlement of America. It is very well known that the precious metals were the principal objects which led the Spanish invaders to penetrate into the interior of Mexico and Peru, and ultimately to devastate and conquer the country, to plunder and destroy its temples, and to tax and enslave its ill-fated inhabitants. It is equally certain that, to escape these scenes of cruelty and oppression, many tribes and fragments of tribes, when further resistance became hopeless, fled towards the north, preferring the enjoyment of liberty and tranquillity upon the chilly borders of the northern lakes, to the pains of servitude in the mild and delightful valleys of Mexico, and the golden plains of the Incas. In this way, many tribes who originally migrated from the north, along the Pacific Ocean, to the Gulf of California, and thence over all New Spain, were returned towards the north over the plains of Texas and the valley of the Mississippi; those tribes nearest the scenes of the greatest atrocities always pressing upon the remoter and less civilized, who, in turn, pressed upon the nations less enlightened than themselves, and finally drove them into the unfrequented forests of the north. Among these terrified tribes, the traditions of the Ojibwais affirm that their ancestors came, and that they originally dwelt in a country destitute of snows. Many tribes who now speak idioms of their language were left upon the way, and have since taken distinctive names. Among these, are the Pottawatamies, the Ottoways, &c. The latter formerly were, as they still remain, the agriculturists. The Miamis and Shawnees, whose languages bear some affinity, preceded them in their flight. The Winnebagoes, speaking a separate and original tongue, came later, and preserve more distinct traditions of their migration. All these tribes carried with them the strong prejudices and fixed hatred excited by the cruelty, rapacity, and cupidity of their European conquerors; and, above all, of that insatiable thirst for gold and silver which led the Spaniards to sack their towns, burn their temples, and torture their people. Cruelty and injustice of so glaring a character must have made upon their minds too deep an impression ever to be forgotten, or completely erased from their traditions. To that memorable epoch we must, therefore, look for the origin of that cautious and distrustful disposition which these tribes have since manifested with regard to the mines and minerals situated upon their lands; and the circumstance seems to offer an abundant excuse, if not a justification, for those prevarications and evasions which present a continual series of embarrassment to every person who seeks through their aid to develop the mineral resources, or describe the natural productions, of their territories. Hence, too, the cause why they are prone to imagine that all mineral or metallic substances obtained or sought upon their lands, are susceptible of being converted or transmuted into the precious metals.
(C.)
The following additional localities of native copper, derived from sources entitled to respect, and accompanied, in some instances, by specimens of the metal, may here be given:—
1. Grand Menou, or Isle Royal, Lake Superior. Captain——, of the schooner——, in the employ of the Hudson’s Bay Company, on Lake Superior, describes this island as affording frequent masses of copper. While becalmed off its shores in the spring of 1822, and, afterwards, in coasting along the island for a distance of one hundred miles, his men frequently went ashore, and never failed to bring back with them lumps of metallic copper, which they found promiscuously scattered among the fragments of rock. These were more abundant in approaching its southwestern extremity, where they unite in representing it to exist in a solid vein. Specimens of limpid quartz, chalcedony, and striped agate, were also brought to me from this island. [J. S. J. J.]
2. On the extremity of the great peninsula, called by the natives Meenaiewong, or Keweena Point, which forms so prominent a feature in the physiognomy of Lake Superior. It occurs in the detached form. [J. H. J. J.]
3. At Point aux Beignes, which is the east cape of the entrance into L’Ance Quewiwenon. A mass from this place was raised from the sandstone rock, which predominates there. [J. Y. B.]
4. At Caug Wudjieu, or the Porcupine Mountains, Lake Superior; in masses, enveloped with a green crust, along the banks of the Carp, or Neemaibee River, which originates in these mountains. [W. M. G. Y. J. J.]
5. On the banks of Lac Courterroile. This lake lies near the source of the River Broule, or Cawesacotai, which enters Lake Superior near La Pointe. It occurs in the alluvial soil, which is a kind of loamy earth, with pebbles intermixed, but of a rich quality, and timbered with beech and maple. It is found mostly in small, flat masses, more or less oxidated. [B. G. J. G. Y.]
6. In a vein on the shore of Lake Superior, between La Riviere de Mort and St. John’s, a little to the west of Presque Isle. [J. J.]
7. On the northeast branch of the Ontonagon River. [J. H.]
8. In the precipitous bluffs called Le Portail, and the Pictured Rocks. A green matter oozes from the seams in these rocks, and forms a kind of stalactites, which is apparently a carbonate of copper. [G. Y.]
These localities embrace a range of more than two hundred miles along the south shore of Lake Superior, which proves how intimately this metal and its ores are identified with the rocks and the soil of that region.
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