94 GEOLOGY OF OHIO. 
well exposed in the cut of the Cleveland and Pittsburgh Railroad, lying 
for some distance just in the grade. | 
About fifty or sixty feet above the Strip Vein, at this point, occurs 
another seam, which is here thin, but higher up in the valley it attains 
a thickness of from three to three and a half feet, and is known as the 
Roger Vein. 
At a variable distance above the Roger Vena Yellow Creek 
Station it is said to vary from sixteen to forty feet—occurs what is known 
as the Big Vein, in dimensions the most important seam in the valley. 
At Linton this is from seven to seven and a half feet in thickness, the 
lower four or five inches being cannel, and containing great numbers of 
fossil fishes and amphibians. The Big Vein is here, as higher up the 
creek, a typical caking coal, of which the value is somewhat impaired 
by the quantity of sulphur it contains. 
About sixty feet above the Big Vein—the interval being filled with 
black and gray shale, sandstone, and a bed of limestone—occurs a coal 
seam, known here as the Groff Vein, from four to five feet in thickness, of 
very good quality. Above the Groff Vein is a great mass of red, gray, 
and green shales, with some red sandstone, two small seams of coal, and 
one or more irregular beds of limestone—a characteristic mass of the 
Barren Measures. 
The coal seams enumerated in the above sketch are supposed to be 
_Nos. 3 (Creek), 4 (Strip), 5 (Roger), 6 (Big), and 7 (Groff) of our lower 
group of coals. 
Borings made in the valley of the Ohio, below the mouth of Yellow 
Creek, all seemed to indicate the presence of a thick seam of coal ata 
distance of eighty or one hundred and forty feet below No. 3; but the re- 
sult of recent explorations has proved that it consists largely of black 
shale, and is practically worthless. Whether it represents Coal No. 1 of 
our series is not yet fully determined, but this seems probable from the 
fact that no coal has been found below it. 
In passing up the Yellow Creek Valley, the coal seams I have enumera- 
ted are all opened, and well known at Collinwood, Hammondsville, Iron- 
dale, and New Salisbury, and no one of the many miners in the valley 
questions their identity and connection. To the latter point the dip of 
_ the strata nearly coincides with the fall of the stream, the coal beds are 
all exposed, and with the exception that some diversity is visible in the 
intervals which separate them, the structure of the valley is uniform 
and regular. Above New Salisbury, however, the stream rises more rap- 
idly than the coal seams, and there is here a slight arch in the strata. 
This carries Coals Nos. 3, 4, and 5 beneath the bottom of the valley, just 
