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  • Usage in publication:
    • Perry Hall Gneiss
  • Modifications:
    • Named
  • Dominant lithology:
    • Gneiss
  • AAPG geologic province:
    • Piedmont-Blue Ridge province
Publication:

Crowley, W.P., 1976, The geology of the crystalline rocks near Baltimore and its bearing on the evolution of the eastern Maryland Piedmont: Maryland Geological Survey Report of Investigations, no. 27, 40 p.


Summary:

Biotite-quartz-plagioclase gneiss interlayered with hornblende-quartz-plagioclase gneiss that outcrops along Bel Air Road north of Perry Hall in Baltimore Co., MD, here named Perry Hall Gneiss. Overlies Bradshaw Layered Amphibolite and Raspeburg Amphibolite of Baltimore Mafic Complex in northeast-southwest syncline. Age of unit given as Cambrian-Ordovician(?).

Source: GNU records (USGS DDS-6; Reston GNULEX).


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).

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