I 2 2 
The Ohio Naturalist. 
[Vol. X, No. 5, 
From Lower Outcrop nearly due east to Indian Creek the 
Upper Mercer dips 1 foot in b\ miles. The Howenstein dips in 
the same direction from Bingham Outcrop to Indian Creek 
8 feet in nearly 7 miles. The Lower Mercer rises from Club 
Lake to Neff Run in a direction 7h miles east and 1 mile north 
6 feet in 7h miles. It is seen at once that the strata lie almost 
horizontally from east to west in the center of the county. 
From Neff Run to Lanterman Outcrop more north than east 
the Lower Mercer falls 19 feet in 3 5 miles, whereas it would be 
expected to rise judging from its position to the west of Neff Run. 
From the same run to Davis well very nearly northeast the Upper 
Mercer lies horizontally having an elevation of 1050 at each place 
and miles between. From Neff Run to Greenhouse Hill 
exactly northeast the Howenstein falls 2 feet in 4 miles. The 
average for the three strata is seen to be about a 2 -foot fall per 
mile. In a direction so much north of east a rise of several feet 
per mile would be expected. 
From the Beardsley Outcrop to Neff Run in a direction l.V 
miles south of east the Lower Mercer rises 8 feet in 4 miles. 
Further comment on the dip and position of the strata in central 
Mahoning County will be made in connection with the Yellow 
Creek and Lowellville sections. 
YELLOW CREEK. 
This stream is a tributary of Mahoning River and flows north- 
ward nearly parallel to Mill Creek half way between the latter 
and the state line. It has a fall of about 210 feet in 5 miles and 
its rapid current has cut a deep gorge from the village of Poland 
to its mouth at Struthers. Accordingly unusually good expo- 
sures of the Potsville formation are afforded. 
Poland Outcrops. At the village of Poland two outcrops of 
limestone occur. The first is seen on the north side just below the 
cemetery forming a conspicuous ledge and water fall in Yellow 
Creek. It is the Lower Mercer and lies at 990 feet above sea. 
The stratum presents here that peculiarity of two layers noted 
elsewhere. The upper layer measures 2 feet, 3 inches and the 
lower 7 inches. Resting directly upon the heavy bed is a 2-inch 
very impure layer of limestone of cone-in-cone structure which 
breaks easily and shows this peculiar structure quite admirably. 
The heavy bed is bluish gray, tough, fossiliferous, and sparkles 
with crinoid stems and calcite crystals. The limestone is directly 
underlain by black carbonaceous shale which is extremely fossili- 
ferous. Seventeen feet of yellowish-gray flaggy sandstone over- 
lies this limestone at this point. 
One and one-half miles from the Mahoning River the City of 
Youngstown has built a dam on A^ellow Creek, the head water of 
which is found a few hundred yards below the above outcrop. 
