TY  - BOOK
AU  - Bascom,F.
TI  - The ancient volcanic rocks of South mountain, Pennsylvania
T2  - U.S. Geological survey. Bulletin
AV  - QE75 .B9 no. 136
PY  - 1896///
CY  - Washington
PB  - Govt. Print. Off.
KW  - Petrology
KW  - Pennsylvania
KW  - Igneous rocks
N1  - "Literature" : p. 87-91; Bibliography : p. 19
ER  -