940 GEOLOGY OF OHIO. 
These statements complete the account of the Great Vein, in Mon- 
roe township, as far as present developments warrant. 
The Upper Freeport Coal (No. 7) of Monroe Township. 
This seam has been opened at several points by the Ohio Central 
Coal Company within the township, but the only mines now in opera- 
tion are the twin mines known as No. 12, and located near Middletown. 
They have been worked for 2 years. The coal in this neighborhood 
has long been mined for local supply, the seam having here acquired 
the name of the Norris coal by which it is quite widely known. Refer- 
ence has already been made to the seam on pages 105-6. The Norris 
coal is there shown to be identical with the Bayley’s Run seam. The 
Great Vein is wanting in this immediate neighborhood, and this fact 
has increased the difficulty of identification. 
The Norris coal has the usual character of the Upper Freeport 
seam for this district. It is a 6-foot seam, divided into two benches by 
a main parting, in addition to which there are frequent thin bands of 
shale that serve to break and weaken the coal. A thin streak of cannel 
often directly underlies the coal. 
The structure of the seam at the Twin mines is represented in 
Fig. XCII: 
PiGURE KELh 
STRUCTURE OF UPPER FREEPORT COAL 
AT MINE NSi2, OHIQ CENTRAL COAL Ca. 
Caumel Streak ov Slate = 
Vivecic Voce ee eee nt 
