No. 136.] 



29 



But in New- York, almost all facilities for their study exist. 

 Its territory lies between the broken and metamorphosed Eastern 

 part of the formations, and the thinner though level strata of 

 the West : it contains these rocks in thick masses, full of fossils, 

 and well exposed in numerous ledges and quarries ; while it has 

 this remarkable feature, that the outcropping edges of the strata 

 chiefly run across the State in successive belts extending from 

 East to West, while the streams which drain the country gene- 

 rally run North and South, thus cutting across the edges of the 

 strata, and exposing in their bordering precipices and ravines 

 excellent natural sections, where almost every layer can be exam- 

 ined. Such instances are well known on the Niagara, the Gene- 

 see, and the West-Canada; and hundreds of less conspicuous 

 examples can be seen between the Hudson and Lake Erie. The 

 eminent English geologist, Mr. Lyell, in his first book on America, 

 remarks, after speaking of his journey through this part of New- 

 York : 



" In the course of this short tour I became convinced that we 

 must turn to the JVew World if we wish to see in perfection the 

 oldest monuments of the earth's history, so far at least as relates 

 to its earliest inhabitants. Certainly in no other country are 

 these ancient strata developed on a larger scale, or more plenti- 

 fully charged with fossils ; and as they are nearly horizontal, the 

 order of their relative succession is always clear and unequi- 

 vocal." This is no more than the truth ; for though rocks of 

 similar age are found on a large scale in England and other parts 

 of Europe, there is nowhere else to be seen so complete, undis- 

 turbed and accessible a series as here. 



It was therefore most fortunate that the munificence of New- 

 York provided for an early and complete survey of her territory ; 

 the facts discovered in the course of which gave at once a stand- 



ard indeed it seems proved by Mr. Hall that the height of these mountain ranges is mainly 

 due, not so much to the uplifting or folding of the strata by subterranean forces of elevation, 

 as to the enormous depth or thickness in which the materials of these rocks were originally 

 deposited in this region. 



The causes of such great inequalities in the thickness of the ancient sea deposits may be 

 easily imagined, though we cannot prove them. We may believe that a great sea-current, 

 like the modern Gulf stream, may have swept over or near this long N.E. and S.W. range, 

 carrying with it and depositing in the vicinity of its course vast quantities of heavy sedi- 

 ment, while to other parts of the sea but little found its way; or that the ancient or prime- 

 val land from which the sediments may have been derived, lay to the eastward. These, 

 however, are mere speculations : all we can be assured of at present, are the facts as above 

 itated. 



