22 GfEOLOGY OF OHIO. 



Berea, of Ohio, is essentially one formation, and is generally a single 

 stratum of sandstone, although sometimes, as has been stated, having a 

 parting of shale. It is here underlain by one hundred feet or more of 

 strata, which contain large numbers of well known Carboniferous fossils, 

 while the Panama Conglomerate, on Chautauqua Lake, is covered by 

 more than a hundred and fifty feet of Chemung shales, full of fossils. If 

 palaeontological evidence is worth anything, anywhere — and every day 

 adds to the proof that it is a safe and sure guide— it is impossible that 

 any part of the Berea grit can be represented by the Panama Conglom- 

 erate. This latter rock is, in fact, one of the several conglomerates of 

 the Chemung, which are known in Pennsylvania as the " Oil Sands." 

 Their true position in Ohio is far below the base of the Cleveland shale, 

 and, at Cleveland, below the lake level. The reason why they have not 

 been reached in the wells bored in Ohio, is that, following the general 

 law, they become thinner and finer going west, and run out altogether, 

 or are represented by the flags of fine-grained sandstone found in the 

 Erie shales. 



That the Berea grit is the equivalent of the Second Mountain sand of 

 Venango county, is possible, but by no means certain. All deposits of 

 this kind, produced by mechanical agents, are far more variable in thick- 

 ness and local in development than limestones, which are laid down con- 

 tinuously, over hill and dale, on the sea bottom. All identifications of 

 sandstones and conglomerates at distant points, are, therefore, to be re- 

 garded with suspicion until confirmed by unquestionable evidence. 



The Bedford shale, which immediately underlies the Berea, and is 

 locally partly or wholly red, is regarded by Prof. Lesley as the equiva- 

 lent of the Catskill of New York and Pennsylvania, but with no other 

 evidence than such as is afforded by its local red color. In the first year 

 of the organization of the Ohio survey the writer, with several assist- 

 ants, went forward and backward over all the interval between the Ohio 

 line and the outcrops of the Catskill in Tioga county, Pennsylvania. 

 The result of this examination was to show that the Catskill could not 

 be identified west of McKean county, Pennsylvania. In the neighbor- 

 hood of Warren, Pennsylvania, every inch of the strata between the 

 coal and the Chemung has been carefully examined, and in that section 

 there is nothing which corresponds to the Catskill in lithological charac- 

 ter or fossils. The same is true of the valley of Oil Creek. The interval 

 here between the Chemung and the coal is less than four hundred feet, 

 and through this interval must pass the Catskill, Vespertine, and Um- 

 bral — strata which in the east have an aggregate thickness of five thou- 

 sand feet — if there is any connection between the supra-Chemung rocks 



