458 GEOLOGY OF OHIO. 
variety of pebbles and small bowlders, very interesting in their litho- 
logical and paleontological characters. In addition to granites,.quartz- 
ites, and greenstones, and all forms of the harder rocks found north of 
the lakes, we have the fossils of all the fossiliferous strata lying to the 
north. These are found best preserved when imbedded in cherty lime- 
stone. With time and patience, one could obtain in these Drift gravel 
banks a very good cabinet of minerals and fossils. It is not uncommon 
to find considerable accumulations of rounded pebbles of bituminous 
coal and small bowlders of our Coal Measure sandrocks. Bowlders of 
the Waverly sandstone and of the Corniferous limestone are very com- 
mon. Away from the Drift terraces I have never found in Washington 
county but a single Drift bowlder, and this I picked up on the high di- 
vide between the Muskingum and Duck Creek, about three hundred 
feet above these streams. There is a possibility that it may have been 
carried up from the banks of the Muskingum by human agency. If 
not thus brought, it was doubtless dropped from floating ice at a time 
of submergence, when at other points in the State large numbers of 
Drift bowlders were dropped on higher ground than this. 
Passing from the Drift and surface geology, we find the stratified rocks 
of the county all belonging to the Coal Measure formation. It is common 
to divide our Ohio Coal Measures into two divisions, Upper and Lower, 
the dividing line being that of the Pittsburgh seam of coal. But the 
Pittsburgh and Wheeling seams are the same, according to the Pennsyl- 
vania geologists, and I have, by careful tracing through the several coun- 
ties, identified the Pomeroy and Wheeling seams as the same. If, there- 
fore, the Pomeroy seam be taken as the base of the Upper Coal Measures, 
nearly all of Washington county lies in the upper series. The Pomeroy 
seam is found in large development west of the Washington county line 
on Federal Creek and its branches in Rome, Berne, and Ames townships, 
and in Marion and Homer townships, in Morgan county. But the seam 
dips to the eastward, and is not seen any where in the west half of Wash- 
ington county. But in the undulations and uplifts in the eastern part of 
the county it appears on Duck Creek and Little Muskingum, and in the 
Newell’s Run uplift in Newport township. The most extensive seam of 
coal in the county is the one found eighty-five to one hundred feet above 
the Pomeroy seam, which has a wide range in Adams, Aurelius, Salem, 
Liberty, Fearing, Lawrence, Newport, etc. This is the upper Salem coal, 
or the “sandstone seam,” so called from the fact that in Salem it gener- 
ally lies under a heavy sandrock. It is generally of sufficient thickness 
for profitable mining, and is of good quality. There is a seam of coal 
