REPORT OF THE STATE PALEONTOLOGIST 1902 985 



AGE OF FOR31ATIONS 



Paleontologic work. The extensive collections of fossils made 

 by Mr Charles Butts were studied by him at Albany under 

 Dr J. M. Clarke's supervision. Prof. H. S. Williams has also 

 studied similar collections made some years ago by himself and 

 his assistants in this region and the paleontologic facts stated 

 below concerning fauna! affinities are those ascertained as a re- 

 sult of the investigations of Dr Clarke, Dr Williams and Mr 

 Butts. Additional facts bearing on the paleontologic problems 

 of the region may soon be expected as a result of the further 

 studies now in progress by Drs Clarke and Williams. 



The conclusions which the writer has drawn from these 

 paleontologic facts he alone is to be held responsible for. 



The shales extending from the lowest exposures up to the base 

 of the Wolf creek conglomerate contain an abundant Chemung 

 fauna and are considered to be of Chemung age. The first Car- 

 bonic life forms appear with the incoming of the Wolf creek con- 

 glomerate and from this point up to practically the base of the 

 Olean con glomerate at Olean rock city where the last Devonic 

 forms disappear, there is a mingling of Devonic and Carbonic 

 forms, the Devonic slowly decreasing, the Carbonic slowly in- 

 creasing. The essential fact so far as the life of these Catta- 

 raugus and Oswayo formations is concerned is that there is an 

 overlapping of Devonic and Carbonic faunas. With this essen- 

 tial fact recognized the position at which the boundary line 

 between the Devonic and the Carbonic shall be drawn becomes,. 

 in some measure at least, a matter of convention. 



It might appear best for some reasons to draw this line at the 

 base of the Wolf creek where Carbonic forms first appear and 

 consider both the Cattaraugus red beds and the Oswayo and 

 Knapp formations as Lower Carbonic. This would make the 

 top of the Chemung the top of the Devonic and would make the 

 Subcarbonic average about 600 feet thick" in this region. 



Because of the thickness of these red beds and their reason- 

 ably certain stratigraphic equivalence with the red beds of the 

 Catskill to the east, and because of the unconformity believed to 

 exist between the Cattaraugus and the Oswayo, the writer pre- 

 fers to draw a provisional boundary between the Devonic and 

 the Carbonic at this point. This would make the Subcarbonic 



