The Devonian of Pennsylvania : Middle and upper Devonian /
The Devonian of Pennsylvania : Middle and upper Devonian /
by Bradford Willard; Keyser limestone and Helderberg group, by Frank M. Swartz; Oriskany group, by Arthur B. Cleaves.
- Harrisburg, Pa. : Dept. of internatl affairs, Topographic and geologic survey, 1939.
- xii, 481 p. : ill. ; 24 cm.
- Bulletin G ; 19 .
At head of title: Pennsylvania Geological Survey, Fourth series.
Bibliography: p. 434-445.
gs 39000291
Geology, Stratigraphic--Devonian.
Geology--Pennsylvania.
Paleontology--Devonian.
QE665 / .P42 1939
At head of title: Pennsylvania Geological Survey, Fourth series.
Bibliography: p. 434-445.
gs 39000291
Geology, Stratigraphic--Devonian.
Geology--Pennsylvania.
Paleontology--Devonian.
QE665 / .P42 1939