106 A'. M. Kindle — Stratigrapkic Relations of the 



tact planes of its upper members will show a westerly declina- 

 tion. Such westerly declination consequently can not be 

 admitted as evidence for the overlap theory. While both the 

 theory of the synchronous origin of the Huron and Cleveland 

 of the Huron River section with the Chagrin, and the theory 

 of the Cleveland shale overlap adjust themselves equally weil 

 to the westerty dip of this shale, another and most important 

 fact fails to find a place in the latter theory. The Cleveland 

 and Chagrin shales, unless the observations of the writer are 

 at fault, are conformable. They must therefore represent 

 successive deposits in the same sea. Since unconformity 

 between the two has been assumed by Mr. Ulrich and is neces- 

 sary to his theory, the evidence against this assumption will be 

 presented in some detail on later pages in the discussion of the 

 stratigraphy. 



Stratigraphy of the Ohio shale group. — The Ohio shale 

 group as defined in the reports of the Ohio Geological Survey 

 comprises three formations. These in descending order are 

 the Cleveland, Chagrin, and Huron shales.* The reader is 



* Note : — A fourth member of this shale series has recently been proposed 

 by Prof. H. P. Cushing (this Journal,! p. 583) nnder the name of the Olm- 

 sted shale. The beds thus designated appear to represent beds generally 

 considered transition beds between the Cleveland and Chagrin by the writer 

 and others. The need or desirability of introducing a new name for transi- 

 tion beds at this horizon is a question on which, doubtless, different views 

 will be held. Arguments could be offered for a new member at the top of 

 the Cleveland where locally there is some interbedding. The writer, how- 

 ever, doubts the desirability of introducing a new term for either set of beds. 

 Professor Cushing believes this Olmsted formation to be unconformable 

 with the Chagrin. Evidence will be offered on later pages indicating that 

 sedimentation was interrupted at this horizon. Professor Cushing is in 

 error in supposing that most of the collections of Cleveland shale fishes have 

 come from his Olmsted shale. One of the richest localities known lies 

 within the "limits of the Cleveland and above the Olmsted as these are 

 delimited on Professor Cushing's manuscript map. Nearly one-fourth ton 

 of these fossils were taken last summer from this locality in the Cleveland. 

 It is unfortunate that Professor Cushing should have interpreted the writer's 

 reference to the collectors who secured much of the fish fossils described by 

 Professor Newberry as applying to the geologists of the Second Geological 

 Survey of Ohio. The three or four collectors alluded to in the lines from 

 my paper quoted by Professor Cushing were, so far as I know, never officially 

 connected with the Ohio Survey. For their splendid unselfish labors in 

 helping to make known the wonderful fish fauna of the Ohio shale I have 

 only the highest admiration. In the matter of discovering and extracting 

 these difficult fossils they were probably much more expert than the mem- 

 bers of the Second Ohio or any other geological survey. But this apprecia- 

 tion must not lead one to overlook the fact that the chief interest of these 

 men lay in securing good specimens rather than in fixing the precise horizon 

 from which they came. Professor Cushing refers to my earlier suggestion 

 that the fish cited by Professor Newberry as evidence of the Carboniferous 

 age of the Cleveland might, through some error, have been derived from 

 a higher horizon, as we now know his "Waverly"' fauna, which he supposed 

 to be at the base of the Cleveland, to have been. Against this suggestion 

 Cashing quotes Professor Newberry to the effect that the three genera 



fThe age of the Cleveland shale, this Journal, vol. xxxiii, pp. 581-584, 1912. 



