272 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull. ^13. 
and it is possible that a new field may be developed at this point. 
From a structural standpoint it seems to be a verj^ promising field, 
and it is to be hoped that before long the drill will be put down in 
this region. 
The quadrangles surveyed in this part of the field are the Union- 
town, Masontown, Brownsville, Connellsville, Latrobe, and Waynes- 
burg. The work on the first two quadrangles has been completed, 
and the results are published in the Masontown-Uniontown folio. 
The Brownsville and Connellsville will likewise be published together, 
and will soon be ready for distribution. The reports on the Waynes- 
burg and Latrobe have not yet been submitted, and it will be some 
time before they are published. 
ALLEGHENY VALLEY. 
Regular areal surveys have also been carried on in the Allegheny 
Valley and in territory adjacent on the east. This includes the Kit- 
tanning, Rural Valley, Eldersridge, and Indiana quadrangles, and is 
located mainly in Armstrong and Indiana counties, but includes also 
a narrow strip of the eastern part of Butler County. 
So far as the stratigraphy is concerned the work is almost identical 
with that of previous surveys. No marked differences occur, except 
that in places extensive developments have taken place in late years, 
and some of the coal beds may be traced beneath the surface with 
much more certainty than was possible at the time of the other sur- 
veys of the region. From an economic standpoint the Upper Freeport 
and the Lower Kittanning coal beds are the most important strati- 
graphic features, and their underlying fire clays are also of great 
value. They have a wide distribution over this territory, and they 
are worked along the Allegheny River, Redbank and Cowanshannock 
creeks, and on the Kiskiminitas River. 
The key rocks in this part of the basin are not so good as they are 
in the Monongahela Valley, and consequently folds have not been so 
definitely located as in the Monongahela Valley. The principal work 
of the present survey is the determination of the structure, and the 
results are very different from those contained in the published 
reports. 
The opinion is prevalent among oil men in this region that the pools 
of oil bear no definite relation to the geologic structure. As deter- 
mined by the second geological survey, the structures in the vicinity 
of Bradys Bend trend regularly about 35° E,, while the oil pools gen- 
erally extend either in an east- west direction, or nearly at right angles 
to this, in a north-south direction. It is manifest that it is impossible 
to harmonize these supposed facts, and consequently it was natural 
for the oil men to arrive at their conclusion that the accumulations of 
oil bear little or no relation to the geologic structure. 
Oil does not occur in the eastern part of the territory, but the prin- 
