THE DELAWARE LIMESTONE 425 



limestone," which was based upon a lithologic character of the 

 formation. 1 



DESCRIPTION OF THE DELAWARE LIMESTONE 



The principal object of this paper is to consider the upper forma- 

 tion of the Ohio Devonian limestones, and decide upon the name 

 which shall be applied to it. The name "Delaware limestone" 

 was first definitely applied to this division as a formation name by 

 Dr. Orton, and published in 1878. He briefly described it as "the 

 blue limestone, thirty-two feet in thickness, which is, from its occur- 

 rence at Delaware, and the extensive use made of it at that point, 

 well named the Delaware limestone.'''' 2 So far as the writer is aware, 

 the term "Delaware limestone," when published by Dr. Orton in 

 1878, was available for the name of a geological formation, and was 

 definitely described in Franklin County, so that there is no doubt 

 regarding its limits. Since 1878 the name "Delaware," forming 

 all or part of the designation, has been applied to at least three other 

 geological divisions; but these names, if considered identical, will 

 not replace Dr. Orton's "Delaware limestone," but will be abandoned 

 because of preoccupation. The names are as follows: (1) Delaware 

 river beds, applied by Dr. I. C. White to an upper Devonian terrane 

 of northeastern Pennsylvania; 3 (2) the identical term, so far as the 

 geographical part of the name is concerned — Delaware stage — was 

 given by Professor Calvin to the lower part of the Niagaran series 

 in eastern Iowa; 4 and (3) the name " Delaware mountain formation" 

 has very recently been given by Mr. George B. Richardson to a 

 Permian formation of southwestern Texas. 5 



Although Dr. Orton's name for this formation apparently referred 

 to the exposures in the vicinity of Delaware, still the section giving 

 its entire thickness which he described, and which may therefore 

 be considered his type section, is in the Scioto valley, about one 



* Clarke and Schuchert, Science, N. S., Vol. X (1899), p. 876; Clarke, N. Y. State 

 Museum, Handbook No. IQ (1903), pp. 8, 21, 22. 



2 Report of the Geological Survey of Ohio, Vol. Ill, Part I, p. 606. 



3 Second Geological Survey of Pennsylvania; G 6 (1882), p. 99. 



4 Iowa Geological Survey, Vol. V (1896), pp. 49, 50. 



5 University of Texas Mineralogical Survey, Bulletin No. Q (November, 1904), 

 p. 38. 



