W. M. Fontaine— Great Conglomerate” on New River. 577 
In the Lower Coals at Westernport, Wm. B. Rogers gives 
four coal beds, averaging in the aggregate about 15 ft. One of 
these is very insignificant (15 in.), and variable. If now we com- 
pare the Lower Coal series at this point with the thickness of 
the fragmental rocks and coals shown over the conglomeritic 
portion of the anthracite fields of Pennsylvania, we see that 
the series has expanded to the northeast no less than to the 
southwest. 
While the above facts indicate that the Lower Barren measures 
thin out to the east, we do not find that they obey the same law of 
diminution with the older formations, at least to such an extent 
as the latter. Still, we find that the increased rate of deposition 
of sediment to the northeast and southwest of the northern 
se of West Virginia is not entirely changed. Selecting 
organtown for our point of comparison, since we have no 
measurements for places farther east, we tind the Lower Barren 
measures here 450 ft. To the northeast, in Pennsylvania, on 
Bennett's Branch, we find them 500 ft. ; while below Charleston, 
on the Kanawha, we have,as I have shown, good reason to 
think them over 500 ft. thick. This comparative uniformity of 
thickness leads us to think that we have, in these rocks, no 
onger formations fringing a continental mass, as would seem 
to be the case with the older formations. 
We can, I think, detect, in some of the formations underly- 
ing the Great Conglomerate, a similar mode of expansion. 
rom what has already been said in connection with the 
eastern limit of the Conglomerate on New River, it would seem 
that the formation cropping out from under it. the Subcarbon- 
iferous, has also in that region a great expansion. This is 
proved by the measurements of Prof. Rogers. He states that 
a triple structure marks the formation everywhere in the State. 
t the top, we find brownish and greenish sandstones, with 
interstratifications of shales; in the middle, red and green, soft, 
decomposing shales; at bottom, limestones. Measured on the 
Potomac, near Westernport, we have, for the whole formation, 
918 ft. with 80 ft. of limestone. In Greenbrier County we have, 
for the entire thickness, 2,132 ft. and 822 ft. of limestone, with 
hardly any shaly seams. To the northeast in Pennsylvania, 
we have, in the anthracite region, a thickness of 2,500 to 3,000 
ft., almost entirely red shale. As usual, the expansion to the 
southwest is attended with a great increase of coal. There 
would seem to have been two eras of coal-making. In the top of 
Little Sewell Mountain, Rogers found a bed of coal close under 
the Conglomerate. This seems to be the equivalent of the 
Sharon coal of Pennsylvania, and if so, indicates a remarkable 
persistence for this slightly developed series. oe 
_ Lower down in the sandstones and shales, a much more 
important formation of coal took place, giving rise in the vicin- 
