Sandstone from Maryland, USA
USA | |
| Pearre, Nancy (1961) Mineral deposits of Maryland excluding fuel, sand and gravel: U.S. Geological Survey Mineral Investigations Resources Map MR-12. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
William S. Cordua |
Seneca sandstone quarries, Seneca, Montgomery County, Maryland, USA