| State | Maryland |
|---|---|
| Name | Port Deposit Gneiss |
| Geologic age | Paleozoic |
| Lithologic constituents | Major
Igneous > Plutonic > Granitic > Granodiorite
Metamorphic > Gneissgranitic gneiss
Igneous > Plutonic > Dioritic > Quartz-diorite
|
| Comments | Radiogenic date from Wetherill et al., 1966 (ref. MD003) |
| References | Cleaves, E.T., Edwards, J., Jr., and Glaser, J.D., 1968, Geologic Map of Maryland: Maryland Geological Survey, Baltimore, Maryland, scale 1:250,000.In 1995 the Water Resources Division of the U.S. Geological Survey digitized the geologic map of Maryland from the 1968 paper map (Reference MD001). Information about products from the Maryland Geological Survey can be found at http://www.mgs.md.gov/.Wetherill, G.W., Tilton, G.R., Davis, G.L., Hart, S.R., and Hopson, C.A., 1966, Age measurements in the Maryland Piedmont: Journal of Geophysical Research, v. 71, p. 2139-2155. |
| NGMDB product | |
| Counties | Baltimore - Cecil - Harford - Baltimore |