The Helderberg Group and the position of the Silurian-Devonian boundary in North America /
| Main Author: | |
|---|---|
| Format: | Book |
| Language: | English |
| Published: |
Washington, [D.C.] :
U.S. G.P.O.,
1964.
|
| Series: | Geological Survey bulletin ;
1180-B. Contributions to stratigraphic paleontology. |
| Subjects: |