GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 



105 



limestone/' which name was given to it by John Gebhard Esq.. 

 who early in the 19th century began the study of the formations 

 of the Schoharie region. Till recently it has been regarded as the 

 eastern extension of the Niagara formation of western New York, 

 under which designation it is referred to in all American text- 

 books of geology and in geologic literature generally. The fossils 

 of this rock were described by Prof. James Hall in 1852, 1 25 

 species being recognized in all. Though the fossils resembled only 

 in a general way those found in the typical Niagara beds of 

 western New York, yet this resemblance together with the fact 

 that it was the only fossiliferous limestone between the Lorraine 

 shales and the waterlimes, was considered sufficient to gain ac- 

 ceptance for this correlation. The recent investigations in the 

 stratigraphy of the State of New York, carried on largely under 

 the direction of the present head of the survey. Prof. John M. 

 Clarke, have thrown a flood of light on the difficult problems 

 of the correlation of beds within the State, ft became apparent 

 that the time-honored correlations of the Coralline with the 

 Niagara could no longer be held and that the Coralline limestone 

 represented a distinct and not hitherto recognized member of the 

 New York Siluric series. Since the name Coralline was inappro- 

 priate as a formation name, that of Cobleskill was substituted for 

 it by Professor Clarke, by which name this formation will hence 

 forth be known. The finding of a Cobleskill fauna above the 

 Salina waterlimes in the Niagara region (North Buffalo), though 

 its significance Avas at first misunderstood, established a definite 

 scale of succession in a region where sedimentation had been con- 

 tinuous and uninterrupted. 2 The problem was finally attacked 

 by Prof. Charles Schuchert and Mr 0. A. Eartnagel from different 

 points and though their conclusions arc dissimilar in some 

 respects, the main fact of the Postsalina age of the Cobleskill 

 limestone was clearly demonstrated by both. 



'Pal. X. Y. 2:321-38, pi. 72-78. 



2 Grabau, A. W. Siluro-Devonic^Contact in Erie oo. N. Y. Geol. Soo. 

 Am. Bui. 11 :347-7G. 



