Pegmatite Dikes

Quartz-albite-microcline-perthite-muscovite granite pegmatites associated with gneiss domes; age 425 +/- 20 m.y. * by radiogenic dating.
State Maryland
Name Pegmatite Dikes
Geologic age Silurian
Lithologic constituents
Major
Igneous > Plutonic > Granitic > Leucocratic-granitic > Pegmatite (Dike or sill)
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 Howard