156 Review of the New York Geological Reports. 



In the extreme southern portion of New York, a few outliers 

 of a conglomerate appear, the same which is developed in the 

 adjoining districts of Pennsylvania, and forms the base of the 

 adjacent coal formation, and considered the equivalent of the 

 millstone grit of England. 



No traces, however, of any limestone exist between this con- 

 glomerate and the Catskill group, occupying the position of that 

 limestone which is so important and remarkable a member of the 

 carboniferous system in Virginia and most of the western States, 

 characterized by the Pentremite and Archimedes, often oolitic in 

 its upper portion, and now universally admitted as the American 

 representative of the mountain limestone of Europe. 



Mr. Mather remarks, (p. 294,) " Prof. Hitchcock was considered 

 years ago, as having almost demonstrated the equivalency of the 

 red sandstone of the Connecticut valley, to the new red sandstone. 

 There can be scarcely a doubt, that the sandstone east of the 

 Blue Ridge and Highlands; that of the Connecticut and of the 

 Housatonic valleys ; and doubtless those of lake Superior, the 

 Rocky mountains, and Nova Scotia, are identical in age, as they 

 are in their general characters and in their associated rocks and 

 minerals, and in their fossils, so far as we know." 



We have spoken now in general terms of all the great geologi- 

 cal formations of the State, up to the base of the coal formations. 

 It remains only, for the present, to make a few remarks on the 

 recent partial deposites. 



Dr. Emmons describes these under the head of tertiary, though 

 he considers them as belonging strictly to the post tertiary, of 

 Lyell. Two thirds of these deposites consists of stiff blue clay, 

 destitute of shells below ; the rest is a yellowish sand, with an 

 intervening mixture of sand and clay. It is in this mixture only 

 that shells have been found. The genera are : My as, Pectens, 

 Tellinas, Saxicavas, and Terebratulas, in a state of wonderful 

 preservation, showing that the deposite took place quietly and 

 without interruption. The upper fossiliferous portion seems, 

 however, to have been to a great extent swept away, as it is 

 found only in sheltered situations. The principal localities of 

 these recent deposites are the great valleys and basins of the east- 

 ern and northern parts of the State. 



To sum up, then, in a few words, the remarks in the forego- 

 ing pages : The geological formations of the State of New York 



