4 
Ap 
246 Address before the Association of American Greologists. ’ 
Thus far, as we have ascended on the scale of rocks, we have 
found, if I mistake not, so full a developement of the European 
formations on this side of the Atlantic, that it would not be 
strange, if at no distant period, this country should become clas- 
sic ground for their study. But we now reach a wide hiatus of 
the extensive groups of the lias, oolite and wealden, which haveas 
yet been scarcely identified on this continent. Humboldt did, 
indeed, express the opinion, that he had met with the oolite in 
the equinoctial zone of South America; and Mr. Lea has deseri- 
bed some fossils from New Grenada, in the seventh volume, se¢- 
ond series, of the Transactions of the American Philosophical Soei- 
ety, which he refers to the same formation. But Yon Buch, in 
his recent splendid work on some of the fossils of South America, 
regards them as belonging to the eretaceous group. Mr. Conrad, 
_ however, has just announced the existence “of well characterized 
and undoubted oolite in the state of Ohio. B-~rullqpoch on the New 
York Survey for 1841. 
When we rise still higher on the geological scale, we anil with 
a remarkable group of rocks, occupying a wide belt from New Jer- 
sey to Alabama, and much surface also in Mississippi, Louisiana, 
Tennessee, Arkansas, and, as I am informed by Mr. Nicollet, ex-. 
tending from Council Bluffs on. the Missouri, several hundred 
miles westward, nearly to. the Rocky Mountains, all of which 
was identified, I believe, first by Prof. Vanuxem, with the creta- 
ceous formation of es although it contains no chalk. The 
subsequent extensive and accurate researches of Dr. Morton, Mr. 
Conrad, and others, have completely confirmed this opinion ; 
it furnishes an interesting example of the value of organic re 
mains in identifying groups of rocks very much unlike in litho- 
logical characters. It is another instance, moreover, of the enor 
mous scale on which geological operations have taken place " 
this country. Frond the recent memoir of the veteran g' 
Von Buch, just referred to, it appears that this same. formation 
ot ahetiaie a considerable portion of South America, and 
: ly predominates. among the secondary rocks of the Andes 
slpelly successful, as in the case of the cretaceous rocks, have 
been the the labors of Conrad, Vanuxem, Morton, Lea, the brothers 
Rogers and others,’ in developing the tertiary deposits of this 
are found, is the island of Mastha’s Vineyerd, or perhaps Nantuck- 
