A syllabus of Pennsylvania geology and mineral resources,
Ashley, Geo. H. b. 1866.
A syllabus of Pennsylvania geology and mineral resources, by George H. Ashley. - Harrisburg, Pa., Topographic and Geologic Survey, 1931. - 160 p. illus., maps (1 fold. col.) 23 cm. - Pennsylvania Geological Survey. Bulletin G 1. . - General geology report ; G1. .
"Pennsylvania Geological Survey. 4th series."
gs 31000177
Geology--Pennsylvania.
Mines and mineral resources--Pennsylvania.
A syllabus of Pennsylvania geology and mineral resources, by George H. Ashley. - Harrisburg, Pa., Topographic and Geologic Survey, 1931. - 160 p. illus., maps (1 fold. col.) 23 cm. - Pennsylvania Geological Survey. Bulletin G 1. . - General geology report ; G1. .
"Pennsylvania Geological Survey. 4th series."
gs 31000177
Geology--Pennsylvania.
Mines and mineral resources--Pennsylvania.