242 Scientifie Intelligence. 
ples,” the latter only occasionally taking the form of a tro 
The strata are a continuation of those of the Appalachian region 
to the southeast, but all the formations are greatly reduc ed in 
Welow: They belong to the following groups, commencing 
belo 
NtAN.—(1) The ae’, sandstones and_ shales 
(vit) nck include the productive “ oil-sands” of the Brad- 
ford district ;* (2) the Catskill adieu (IX), 250 feet thick at 
Bradford (while 2560 feet in Blair County, just southeast of the 
center of Pennsylvania, and 5000 to 6000 ih at the extreme 
eastern outcrops on the Lehigh and Susqueha Rivers). 
B ARBONIFEROUS.—(3) The Pocono sandstone Aba 250 
thi ou 
f=) 
the Sharon sppptorierats of We stern 1 Pennsylvania and the con- 
glomerate of the Ohio geologists), and, above this, of two sand- 
stone strata with the Alton Coal-bed between. N ext (6) bebe 
coal-bed of Western Pennsylvania, and the Dagus, situated 
rah the “Clermont ferriferous limestone (4 to 8 8 sare an 
of the ruthie area is about sixteen miles (the northern wo to 
three miles of it in the State of New York), and the greatest 
breadth is nearly eight miles. In its line, six miles to the south- 
west, lies the small Kinzua oil district, and half way betwee? the 
two the “ Big Shanty” er and toward the southern ss 
ary of the county there are a few wells near orgie? an 
_* The “oil-sands” (or casita of Western Lecce be a, vn a 
oil-district—are beds in the Catskill sandstone (IX) an cee 8 uve a highe 
position “ea sage than those o: ord oil-di 
Ashburner states dae a 000 feet, 
sive” in view of the fact that a poate from the the ay Productive 
of 
rag to And e base (?) of the Trenton, carefully measured po him, anieed a thickness 
