A century of science in America

by Unknown

The formations as he has them from the bottom upwards are: (1) Ferruginous sand, (2) Plastic clay, (3) Calcaire Silicieuse of the Paris Basin, (4) London Clay, (5) Calcaire Ostrée, (6) Upper marine formation, (7) Diluvial.

The grandest of these early stratigraphic papers, however, is that by Lardner Vanuxem (1792–1848), of only three pages, entitled “Remarks on the Characters and Classification of Certain American Rock Formations” (16, 254, 1829). Vanuxem, a cautious man and a profound thinker, had been educated at the Paris School of Mines. James Hall told the writer in a conversation that while the first New York State Survey was in operation, all of its members looked to Vanuxem for advice.

In the paper above referred to, Vanuxem points out in a very concise manner that:

“The alluvial of Mr. Maclure ... contains not only well characterized alluvion, but products of the tertiary and secondary classes. Littoral shells, similar to those of the English and Paris basins, and pelagic shells, similar to those of the chalk deposition or latest secondary, abound in it. These two kinds of shells are not mixed with each other; they occur in different earthy matter, and, in the southern states particularly, are at different levels. The incoherency or earthiness of the mass, and our former ignorance of the true position of the shells, have been the sources of our erroneous views.”

The second error of the older geologists, according to Vanuxem, was the extension of the secondary rocks over “the western country, and the back and upper parts of New York.” They are now called Paleozoic. Some had even tried to show the presence of Jurassic here because of the existence of oölite strata. “It was taken for granted, that all horizontal rocks are secondary, and as the rocks of these parts of the United States are horizontal in their position, so they were supposed to be secondary.” He then shows on the basis of similar Ordovician fossils that the rocks of Trenton Falls, New York, recur at Frankfort in Kentucky, and at Nashville in Tennessee.

“It is also certain that an uplifting or downfalling force, or both, have existed, but it is not certain that either or both these forces have acted in a uniform manner.... Innumerable are the facts, which have fallen under my observation, which show the fallacy of adopting inclination for the character of a class,” such as the Transition class of strata. He then goes on to say that in the interior of our country the so-called secondary rocks are horizontal and in the mountains to the east the same strata are highly inclined. “The analogy, or identity of rocks, I determine by their fossils in the first instance, and their position and mineralogical characters in the second or last instance.”

It appears that Isaac Lea (1792–1886) in his Contributions to Geology, 1833, was the first to transplant to America Lyell’s terms, Pliocene, Miocene, and Eocene, proposed the previous year. The celebrated Claiborne locality was made known to Lea in 1829, and in the work here cited he describes from it 250 species, of which 200 are new. The horizon is correlated with the London Clay and with the Calcaire Grossier of France, both of Eocene time (25, 413, 1834).

Timothy A. Conrad began to write about the American Tertiary in 1830, and his more important publications were issued at Philadelphia. His papers in the Journal begin with 1833 and the last one on the Tertiary is in 1846.

The Tertiary faunas and stratigraphy have been modernized by William H. Dall in his monumental work of 1650 pages and 60 plates entitled “Contributions to the Tertiary Fauna of Florida” (1885–1903). Here more than 3160 forms of the Atlantic and Gulf deposits are described, but in order to understand their relations to the fossil faunas elsewhere and to the living world, the author studied over 10,000 species. Since then, many other workers have interested themselves in the Tertiary problems. Much good work is also being done in the Pacific States where the sequence is being rapidly developed.

The Discerning of the Eastern Cretaceous.—The Cretaceous sequence was first determined by that “active and acute geologist,” Samuel G. Morton (1799–1851), but that these rocks might be present along the Atlantic border had been surmised as early as 1824 by Edward Hitchcock (7, 216). Vanuxem, as above pointed out, indicated the presence of the Cretaceous in 1829. In this same year Morton proved its presence before the Philadelphia Academy of Natural Sciences.