| Publication Type: | Journal Article |
| Year of Publication: | 1920 |
| Authors: | T. Wayland Vaughan |
| Journal: | United States Geological Survey Professional Paper |
| Volume: | 128 |
| Pagination: | 61 - 66, pl. 10 |
| Date Published: | 1920/// |
| URL: | http://books.google.com/books?id=A0oRAAAAIAAJ |