D2, GEOLOGY OF OHIO. 
FIGURE XOX . 
STRUCTURE OF LIMESTONE COAL 
AT. GREENT OWN. yuo 
Putacarmn Wht Lumestone. ah 
5 65 a 
eiace cc, Sn 
Par ae ean ee ae 
Bone Coa 
ae ee ee ee 
Q Qu were em, eee cee ees Gen eee ni eT 
siderable amount of coal was mined, the monthly output reaching 150 
ears, but the mine has now been closed for some months on account of 
litigation within. the company. ‘The coal was largely used as a steam 
coal by the railroad. It is undoubtedly better adapted to steam genera- 
tion than to other uses. 
The roof of the coal is the Putnam Hill limestone, between which 
and the seam a few inches of protecting shale intervene. The roof is 
very firm and strong, and is easily held in place. 
The under clay is a plastic clay, quite white, and valuable for 
potters’ use. It would make a troublesome bottom, probably, in mines 
worked on a large scale. 
The seam is seen to be divided into two well-marked benches, an 
upper and a lower. Between them there is a marked difference in 
quality, the upper bench having in all respects a great advantage. 
The upper bench is 3 feet thick, and is an open-burning, bright 
and well-jointed coal. It mines in fairly large blocks, but breaks 
easily, and therefore does not bear handling as well as many seams. It 
is said to yield a light colored ash, but the composition would lead us 
to expect a reddish ash. The ash is not excessive in amount, and this 
bench is not given to troublesome “clinker.” Its average composition 
is shown in the following analysis: 
