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  • Usage in publication:
    • Bradshaw Layered Amphibolite
  • Modifications:
    • Named
  • Dominant lithology:
    • Amphibolite
    • 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:

Bradshaw Layered Amphibolite here named for town on Little Gunpowder Falls and assigned to Baltimore Mafic Complex. Consists of interlayered amphibolite and hornblende-quartz-plagioclase gneiss, with zones of massive and laminated amphibolite. In thrust-fault contact with Oella Formation (new) of Wissahickon Group; underlies Franklinville Gneiss (new) or Perry Hall Gneiss (new) in northeast-southwest synclines; passes into Raspeburg Amphibolite (new) of Baltimore Mafic Complex on northwest limb of Perry Hall syncline. Age of entire Complex is shown as Cambrian(?). [Name in conflict with Art. 30(b) of the NACSN Code.]

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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