The Ohio Naturalist. 
[Vol. X, No. 5, 
1 1 8 
measures 3 feet 6 inches. The rich bed of iron ore above it was 
formerly mined and used in the manufacture of paint. 
This limestone is being burned for fertilizer on the John Fitch 
farm near West Austintown. 
McMahon Outcrop. About 1J miles southeast of the Ripple 
outcrop an exposure of limestone occurs on McMahon Run and 
on the farm of Ambrose McMahon. The full thickness is not 
now exposed but reported to be 2 feet or more in a coal shaft at 
this point. Drillings close around gave a thickness of to 3 
feet. In one hole reported by Mr. McMahon a 2-foot coal was 
penetrated 10 feet above the limestone. As seen in the run the 
limestone lies at about 1040. The coal at the shaft lies 25 feet 
below the limestone or at 1015, but in one of the drill holes at 20 
feet below that stratum. The limestone is overlain by a rich 
bed of iron ore as at the Ripple outcrop and would seem from all 
the data to be the Lower Mercer although 12 feet higher than at 
previous outcrop. Undulation will easily account for this 
difference. The 2 foot coal above it would seem to be the coal 
belonging to the Upper Mercer but no trace of this limestone or 
its coal is seen in the run above the shaft where the next 35 feet 
of strata are exposed. 
Smith Corners. At Smith Corners about one mile a little 
south of east from the McMahon outcrop William Gardner pen- 
etrated a limestone of about 18 inches thickness at 1090 above 
sea. The dip toward the southeast in eastern Mahoning County 
is only about 5 feet per mile, the interval therefore of 55 feet 
indicates rather clearly that this is the Howenstein limestone. 
The McMahon outcrop, Smith Comers and Poland are nearly in 
line and the matter of dip in that direction will be considered 
further under Poland outcrops. 
MILL CREEK AND TRIBUTARIES. 
This stream empties into the Mahoning River at Youngstown 
after crossing the eastern end of Mahoning County from south 
to north. Its bed for more than 7 miles from its mouth lies 
below the horizon of the Lower Mercer limestone, and the scanty 
outcrops of the limestones, therefore, are found on its tributaries. 
Facodi Outcrop. In the first ravine to the east above the fall 
at the old Lanterman Mill on Mill Creek, the Lower Mercer is 
first seen on the land of Una Facodi at 1010 feet above sea. The 
exposure is poor and the thickness not seen. It is underlain by 
gray sandy shale and flaggy sandstone down to Mill Creek. This 
sandstone is the Upper Massillon and it constitutes the rock 
walls of Mill Creek gorge. 
Lanterman Outcrop. About one-fourth mile south of the 
Facodi outcrop and on the German Lanterman farm the Lower 
Mercer outcrops in a ravine which crosses the north and south 
