266 
The American Geologist. 
April, 1896 
In folded regions such conditions of deposition as have just been des¬ 
cribed determine the position of synclines of the greatest magnitude, 
the synclines of deposition. Such folds are further characterized by a 
very steep dip on the shoreward side and by the stratigraphy, which 
should include a massive bed of shale. When sufficiently characteristic 
to be recognized, the syncline of deposition thus becomes an evidence 
of proximation to shore, with axis parallel to its general trend ; the 
infolded strata may also indicate the prolonged duration of the neigh¬ 
boring shore line. 
Thus the causal relation which exists between sedimentation and 
folding is appealed to to aid in the determination of ancient shore lines. 
Mr. David White communicated informally some preliminary results 
of his recent work under instructions from the director of the U. S. 
Geol. Survey in the stratigraphic paleontology of the lower portion of 
the Carboniferous proper (Mesocarboniferous) and of the Pottsville 
series in particular. The speaker exhibited columnar sections of the 
series near Coxton, Pottsville and Tremont, Pa.; Piedmont, the New 
river and the Tug river, W. Va.; Soddy, Tenn. : and in the Warrior 
coalfield, Ala., on which were indicated, the stratigraphic position and 
vertical extent of the paleontologic divisions of the Pottsville series. 
Although the plant collections are often fragmentary or represent, in 
some regions, only one or more levels in some of the sections, the indi¬ 
vidual collections are generally clearly referable to one of the floral 
divisions,—viz., Pocahontas, Horsepen, and Sewanee, in ascending 
order,—suggested in the author’s preliminary paper on the New River 
section at the Baltimore meeting of the Geological Society of America, 
while the approximate level in that division is also frequently indicated 
with considerable reliability, as is shown by stratigraphic verification. 
The limits of these floral divisions, now fairly well determined in the 
New River section, have been traced somewhat precisely through the 
Plat Top-Tug River section, where the total thickness is seen to expand 
far beyond the 1700 feet of the New River section, while material from 
two localities in the Big Stone Gap, Va., region shows the presence of a 
flora belonging to the Sewanee division, at a probable hight of 2300 
feet above the base of the series, denoting, perhaps, the maximum 
thickness of the series near this point in the central Appalachian trough. 
Special importance attaches to the author’s conclusions that the in¬ 
clusion of the lower part of the “ Walden sandstone” of Hayes, repre¬ 
sented by the “ Second series” of Safford, in the upper or Sewanee di¬ 
vision of the Pottsville series is fully demonstrated by the fossils of the 
West Virginia and the type (Pottsville) sections, while the underlying 
terranes, including the “ Millstone grit” and upper part, at least, of the 
“ Sub-conglomerate” of Safford or the “ Lookout sandstone” of Hayes 
are referable to the Horsepen division. Such scanty fossil material from 
Alabama as is available indicates that in the Warrior coalfield the War¬ 
rior and Black Creek seams belong in the Horsepen division, while the 
Newcastle and Pratt seams appear to fall within, certainly not above, 
the Sewanee division, though the Pratt Seam is said to be about 1800 
feet above the base of the series. Such a correlation necessitates placing 
the boundary of the lower productive Coal Measures many hundreds of 
feet higher in Tennessee and Alabama than has yet been done by the 
geologists in those states. It also follows that the Lykens Valley coals 
in Pennsylvania, the New River and Pocahontas coals of West Virginia, 
as well as the valuable coking coals of Tennessee and Alabama, all seem 
to fall within the limits of the Pottsville series. 
Attention was also called to the absence of the Pocahontas and even 
the Horsepen division floras in some of the thin sections of the series in 
this basin, apparently disproving the generally accepted view that the 
difference between the thick and the thin sections is wholly a question 
of expansion. w. F. Morsell. 
