288 =F. B. Andrews— Comparison between the Ohio and 
down in the geosynclinal, but remained on the higher margin 
as in Ohio, and the original trough by which connection was 
had with the sea lay probably to the east. 
id the same geosynclinal trough extend in the opposite 
direction from the Kanawha valley, i. e., to the northeast through 
Pennsylvania? Ifthe equivalency of the Pittsburgh seam has 
been rightly determined in the Cumberland and Broad Top 
coal-fields, we have in the former, according to Mr. Tyson, 
1,100 feet of productive measures below that seam, and in the 
latter about 700, according to Prof. Lesley. .Prof. Lesley has 
recently reported finding in the Broad Top field thin coals in 
the lower Carboniferous, in strata which he regards as equiva- 
lents of the Waverly Berea grit of Ohio. This is a discovery 
of the highest interest, but it will not effect this discussion, 
since I confine myself to what we term the Productive coal- 
measures. The geological interval between the middle of the 
Waverly, with the Chester limestone above, and these measures 
is a very great one. It may be remarked in this connection 
measures contain no register of themselves in seams of coal, the 
they were formed. Prof. Lesquereux, in his chart of grouped 
sections in the fourth volume of the Kentucky Survey, places 
all the coal-seams of Wilkesbarre, Pittston, Scranton and Car- 
bondale below the horizon of the Pittsburgh seam. In the 
Pottsville region Mr. Daddow claims that seam G. of his series, 
is the equivalent of the Pittsburgh seam. The seam G. 1s 
feet above the lowest seam in the series, one imbedded in con- 
glomerate. If we accept this equivalency we find no proof 0 
the existence of the deep geosynclinal trough in that direction. 
, again, the conglomerate under the anthracite basins 1s the 
equivalent of the conglomerate of Western Pennsylvania and 
Ohio, and they were once one and continuous as the Pennsy L- 
-vania geologists affirm, then, since to the west, the ge ee? 
ate was not deposited until after the great West Virginie 
trough was filled and the waters in the general subsidence 
