campbell.] BITUMINOUS COAL FIELD OF PENNSYLVANIA. 275 
BEAVER VALLEY. 
Only a small territory has been surveyed in Beaver Valley. This 
territory is included in the Beaver quadrangle, which lies mainly in 
Beaver County. The structure and stratigraphie results differ very 
little from those obtained in previous surveys. The principal point 
of improvement is in the excellent topographic map upon which the 
material will be shown and in the great detail with which the stratig- 
raphy was worked. The Upper Freeport and Lower Kittanning coal 
beds are the principal sources of fuel in this region, but the most 
valuable deposits are probably the fire clays which are associated 
with the Kittanning group of coals. These are widely developed 
geographically and have been worked for a great many years. They 
have given the region prominence in the manufacture of clay pro- 
ducts, but not all of the raw material has been derived from the local 
beds. Some oil and gas occurs in this region, but the fields are not 
large and the wells are generally small producers. 
