94 
The Ohio Naturalist. 
[Vol. X, No. 5, 
“ * * * * Toward the southwest (from Lowellville) the forma- 
tion becomes more and more sparing in its exposures, and thin- 
ner, until in southwestern Stark County and northeastern Tus- 
carawas County it disappears, and the Putnam Hill Limestone 
comes in on nearly the same horizon, but stratigraphically dis- 
tinct.” [Ohio Geol. Sur. Vol. IX, Bull. 4, p. 174.] 
From this brief review of the literature on these limestones 
it is quite apparent that three limestones are recognized in 
Western Pennsylvania below the Lower Kittanning Coal, and 
in Ohio four are recognized below the same horizon. In the 
former state the Lower Mercer and Vanport are the more 
important stratigraphical horizons; in the latter state the 
Lower Mercer and the Putnam Hill have that distinction. It is 
also apparent that uncertainty characterizes the present knowl- 
edge of the presence and character of the westward extension 
of the Vanport limestone from eastern Mahoning County, and 
likewise the eastward extension of the Putnam Hill from Central 
Stark County. The Lower Mercer is regarded as the unfailing 
limestone from Mercer County, Pennsylvania, to Zanesville, 
and as the lowest and earliest limestone in the Lower Coal 
Measures. The Upper Mercer is conceded to be present in 
many places, but by no means so regularly present as the Lower 
Mercer. 
SURFACE, STREAMS, AND ELEVATIONS. 
From central and southern Stark County southwestward, it 
would appear from the Ohio Reports that these limestones are 
fairly well known and the same can be said of them on the eastern 
line of the state. But from central Stark County to the Pennsyl- 
vania line they are not well known. Consequently a somewhat 
careful examination has been made of this territory covering 
an extent of about fifty miles. Of the region examined all but 
a little in southern Stark County is deeply drift covered, and 
only now and then can the strata be seen to emerge from the 
drift mantle save along streams and even here long intervals 
often occur between meager outcrops. 
From west to east the following streams and tributaries 
have been examined for outcrops of the above limestones: 
Nimishillen Creek, Mahoning River, Island Creek, Little Mill 
Creek, Turkey Broth, Meander Creek, McMahon Run, Diehl 
Creek, Mill Creek, Neff Run, Indian Creek, Yellow Creek, Burgess 
Run, and Furnace Run, all of which are shown on the accom- 
panying map of Stark and Mahoning Counties. 
Elevation will be seen to be an exceedingly important factor 
in obtaining the results of this investigation and it is constantly 
employed in determinations. The elevations given were ob- 
tained by level from elevations indicated in the field by the 
