4 
620 GEOLOGY OE OHIO. 
the beds at this point. There are no fossils found in either. At Piketon, 
where the junction between the two groups of rocks is shown with all 
possible distinctness, it appears, from the occurrence of thin beds of 
black shale in the lowermost twenty feet of the Waverly beds, that the 
formation of a shale entirely like the Huron in character was resumed 
more than once in the early days of the deposition of the Waverly group ; 
but these returns of previous conditions in the seas were of short dura- 
tion, and were soon lost altogether. 
A few thin courses of solid stone of remarkable evenness and of very 
fine grain occur almost every where at ten to twenty feet above the base. 
They can be seen to excellent advantage in the river bank, on the land 
of Mr. John Gregg, two miles above Piketon. Analysis shows that these 
hard and ringing layers have a large enough amount of lime and mag- 
nesia in their composition to put them in the list of impure limestones. 
This is the only known occurrence of calcareous layers in the whole Wa- 
verly series until, at least, its very summit is reached in the regions to 
the eastward of Pike county. The composition of two specimens is 
shown in the appended analyses made by Prof. Wormley, Chemist of the 
Survey. The sample marked No. 1 was obtained from Wolf Run, one 
mile east of Buchanan. No. 2 comes from the neighborhood of Mineral 
Springs, on the north line of Adams county: 
Silicious Mathers sees aees ic eee sec neta e eee eee ae RAR aRRE Toners 71.40 58.80 
IN orton BiAC| WROD cdcagdess oo0b500 bel baadibum dues cleaetaelct slates teclawe ces amie eae 2.40 5.80 
Garbonate ron lime ssecciewcens cc destanee coe eeisctse ces oe astra ee ALA) 27.00 
Carbonate ‘Of MaeMeSiar cies. .ccccy wives ueccassltaseesiesesscenclastvece acs: 1.05 8.62 
99.25 100.22 
The Waverly shales were evidently formed under very different condi- 
tions from those to which the origin of the overlying group must be re- 
ferred. The latter never show ripple-marks, sun-cracks, or other indica- 
tions of having been formed in shallow water, while the Waverly shales 
are conspicuously marked in this way. The surfaces of successive layers, 
for many feet in thickness, are often covered with ripple-marks, all of 
them holding the general direction of north 53° west, or south 53° east.* 
Exposures of these beds are of common occurrence through all of the 
western half of the county. On Wolf Run, a small branch of Peepee 
* The Survey is indebted to H. W. Overman, Esq., County Surveyor, for a very care- 
ful series of measurements. Of twenty-four observations, fourteen were found south 
58° east, as given above. Four points showed south 65° east; one south 46° east; one 
south 57° east. The points that showed south 65° east overlie the other exposures, 
and probably indicate a real change of direction in the wave action. 
