H54 



Report of the State Geologist. 



To indicate the base of the Chemung formation across Chenango and 

 Otsego counties is a matter of some difficulty. There is a difference of 

 opinion among working geologists as to where it occurs in this region, and 

 possibly as yet insufficient study has been given to these higher rocks to 

 enable the determination of this point. Vanuxem's interpretation of this 

 region is of little value on account of his failure to separate the Oneonta 

 from the .Catskill formation, as will be seen by reference to the Geological 

 Map of the State of New York, of 1842. Professor James Hall has given 

 careful attention to the classification of these rocks and mentioned them in 

 numerous publications, among which might be cited his paper before the 

 National Academy of Sciences, in which he clearly stated his interpretation 

 when he said : " The fossiliferous beds of the Chemung are found lying upon 

 that formation [the Oneonta] between Norwich and Oneonta, and to the east 

 of Sidney Plains, and at or near Franklin, where they apparently pass 

 beneath the great red - sandstone formation of the Catskills. 11 1 Professor 

 Henry S. Williams placed the base of the Chemung considerably higher, 

 beginning above the Tropidolept/us cwmaims fauna near Port Crane, 

 apparently with the Spirif&r mesastriaUs zone well toward the top of the 

 hill south of Port Crane. 2 Mr. Darton evidently followed Professor Hall's 

 classification and stated that : " From Franklin, westward, the Oneonta- 

 Chemung boundary is clearly marked by the abrupt change from red beds to 

 grey shales and soft sandstones.' 13 Finally, Professor Clarke, as a result of 

 his studies in the vicinity of Greene, concluded that the fossils in the shales 

 and sandstones overlying the Oneonta formation "are of typical Chemung 

 expression," 4 and consequently referred the rocks to the Chemung formation. 



Professor Williams described the lowest Chemung fauna of the Cayuga 

 lake meridian as found on the high hill south of Ithaca in Danby township 

 in the southern part of Tompkins county " stratigraphically 1,300 feet or 

 more above the Genesee shale " 5 The following fauna from this locality is 

 given by Professor Williams : 



" Productella larlwi/mosa, 



AmbocosUa wmbonata var. grega/ria, 



Orthis vm/pressa ( second variety, wide and large), 



A t pa reticular is, 



and a few other imperfect fossils." 6 



• Science (old series), Vol I., Dec. 11, 1880, p. 290. 



a Proceedings American Association Advancement of Science, Vol. XXXIV., section IX. of Chart. 

 3 American Journal of Science, third series, Vol. XLV., 1893, p. 207. 



4 Thirteenth Annual Report State Geologist [New York] , p. 543 ; also see section on p. 556. 

 •'■Bulletin United States Geological Survey, No. 3. 1884, p. 21. 

 6 /«<*., p. 21. 



