62 Charles Schuchert — Historical Geology, 1818-1918. 



only three pages, entitled " Remarks on the Characters 

 and Classification of Certain American Rock Forma- 

 tions" (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 oper- 

 ation, 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 second- 

 ary 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 oolite strata. "It was taken for 

 granted, that all horizontal rocks are secondary, and as 

 the rocks of these parts of the United States are horizon- 

 tal in their position, so they were supposed to be second- 

 ary. y ' 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 downf ailing 

 force, or both, have existed, but it is not certain that 

 either or both these forces have acted in a uniform man- 

 ner. . . . Innumerable are the facts, which have fallen 

 under my observation, which show the fallacy of adopt- 

 ing 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 iden- 

 tity of rocks, I determine by their fossils in the first 

 instance, and their position and mineralogical characters 

 in the second or last instance. ' ' 



