Urbana Formation

Dark gray to green sericite-chlorite phyllite, metasiltstone, and quartzite; thin lenses of impure marble and calcareous phyllite occur locally.
State Maryland
Name Urbana Formation
Geologic age Late Precambrian (?)
Lithologic constituents
Major
Metamorphic > Metasedimentary > Metaclastic > Metasiltstonemeta-argillite
Metamorphic > Metasedimentary > Metaclastic > Phyllite
Minor
Metamorphic > Metasedimentary > Metaclastic > Quartzite
Metamorphic > Metasedimentary > Metacarbonate > Marble
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/.

NGMDB product
Counties Frederick - Montgomery