Wernerian Geology in North America
The Father of American Geology.—Historical Geology begins in America with William Maclure’s Observations on the Geology of the United States, issued in 1809. This was the first important original work on North American geology, and its colored geological map was the first one of the area east of the Mississippi River. The classification was essentially the Wernerian system. All of the strata of the Coastal Plain, now known to range from the Lower Cretaceous to Recent, were referred to the Alluvial. To the west, over the area of the Piedmont, were his Primitive rocks, while the older Paleozoic formations of the Appalachian ranges were referred to the Transition. West of the folded area, all was Floetz or Secondary, or what we now know as Paleozoic sedimentaries. The Triassic of the Piedmont area and that of Connecticut he called the Old Red Sandstone, and the coal formations of the interior region he said rested upon the Secondary. The second edition of the work in 1817 was much improved, along with the map, which was also printed on a more correct geographic base. (For greater detail, see Merrill, Contributions to the History of American Geology, 1906.)
Even though Maclure’s geologic maps are much generalized, and the scheme of classification adopted a very broad one, they are in the main correct, even if they do emphasize unduly the rather simple geologic structure of North America. This fact is patent all through Maclure’s description. Cleaveland also refers to it in his treatise of 1816, and Silliman in the opening volume of the Journal (1, 7, 1818) says: “The outlines of American geology appear to be particularly grand, simple, and instructive.” Then, all the kinds of rocks were comprehended under four classes, Primitive, Transition, Alluvial, and Volcanic. It is also interesting to note here that in 1822 Maclure had lost faith in the aqueous origin of the igneous rocks and writes of the Wernerian system as “fast going out of fashion” (5, 197, 1822), while Hitchcock said about the same thing in 1825 (9, 146).
The Work of Eaton.—Amos Eaton, after traveling 10,000 miles and completing his Erie Canal Report in 1824, “reviewed the whole line several times,” and published in 1828 in the Journal (14, 145) a paper on Geological Nomenclature, Classes of Rocks, etc. The broader classification is the Wernerian one of Primitive, Transition, and Secondary classes. Under the first two he has fossiliferous early Paleozoic formations, but does not know it, because he pays no attention anywhere to the detail of the entombed fossils, and all of his Secondary is what we now call Paleozoic. The correlations of the latter are faulty throughout.
Then came his paper of 1830, Geological Prodromus (17, 63), in which he says: “I intend to demonstrate... that all geological strata are arranged in five analogous series; and that each series consists of three formations; viz., the Carboniferous [meaning mud-stones], Quartzose, and Calcareous.” We seem to see here expressed for the first time the idea of “cycles of sedimentation,” but Eaton does not emphasize this idea, and the localities given for each “formation” of “analogous series” demonstrate beyond a doubt that he did not have a sedimentary sequence. The whole is simply a jumble of unrelated formations that happen to agree more or less in their physical characters.
“I intend to demonstrate,” he says further, “that the detritus of New Jersey, embracing the marle, which contains those remarkable fossil relics, is antediluvial, or the genuine Tertiary formation.” This correlation had been clearly shown by Finch in 1824 (7, 31) and yet both are in error in that they do not distinguish the included Cretaceous marls and greensands as something apart from the Tertiary.
One gets impatient with the later writings of Eaton, because he does not become liberalized with the progressive ideas in stratigraphic geology developing first in Europe and then in America, especially among the geologists of Philadelphia. Therefore it is not profitable to follow his work further.
Early American Text-books of Geology.—The first American text-book of geology bears the date of Boston 1816 and is entitled An Elementary Treatise on Mineralogy and Geology, its author being Parker Cleaveland of Bowdoin College. The second edition appeared in 1822. It also had a geologic map of the United States, practically a copy of Maclure’s. To mineralogy were devoted 585 pages, and to geology 55, of which 37 describe rocks and 5 the geology of the United States. The chronology is Wernerian. Of “geological systems” there are two, “primitive and secondary rocks.”
In 1818 appeared Amos Eaton’s Index to the Geology of the Northern States, having 54 pages, and in 1820 came the second edition, “wholly written over anew,” with 286 pages. The theory of the later edition is still that of Werner, with “improvements of Cuvier and Bakewell,” and yet one sees now-a-days but little in it of the far better English text-book. Eaton did very little to advance philosophic geology in America. What is of most value here are his personal observations in regard to the local geology of western Massachusetts, Connecticut, southwestern Vermont, and eastern New York (1, 69, 1819; also Merrill, p. 234).
We come now to the most comprehensive and advanced of the early text-books used in America. This is the third English edition of Robert Bakewell’s Introduction to Geology (400 pages, 1829), and the first American edition “with an Appendix Containing an Outline of his Course of Lectures on Geology at Yale College, by Benjamin Silliman” (128 pages). Bakewell’s good book is in keeping with the time, and while not so advanced as Conybeare and Phillips’s Outlines of 1822, yet is far more so than Silliman’s appendix. The latter is general and not specific as to details; it is still decidedly Wernerian, though in a modified form. Silliman says he is “neither Wernerian nor Huttonian,” and yet his summary on pages 120 to 126 shows clearly that he was not only a Wernerian but a pietist as well.