U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Loch Raven Schist
  • Modifications:
    • Named
  • Dominant lithology:
    • Schist
  • 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:

Loch Raven Schist of Wissahickon Group here named for Loch Raven Reservoir, Baltimore Co., MD. Unit is predominantly a medium-grained biotite-plagioclase-muscovite-quartz schist with pods of vein quartz. Subdivided into (ascending) Rush Brook and Hydes Marble Members. Thickness ranges to more than 600 m. Overlies Cockeysville Marble; underlies Oella or Piney Run Formations of Wissahickon Group. Age is Cambrian-Ordovician(?).

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


Map showing publication footprint
  • Usage in publication:
    • Loch Raven Schist*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Piedmont-Blue Ridge province
Publication:

Drake, A.A., Jr., Sinha, A.K., Laird, J., and Guy, R.E., 1989, The Taconic orogen, IN Hatcher, R.D., Jr., and others, eds., The Appalachian-Ouachita Orogen in the United States: Geological Society of America, The Geology of North America, The Decade of North American Geology (DNAG), v. F-2, p. 101-177.


Summary:

Following Drake (1986, Geological Society of America, Abstracts with Programs, v. 17, no. 7, p. 566), Glenarm Group consists of Setters Formation, Cockeysville Marble, and Loch Raven Schist. The Oella Formation is part of an overlying thrust stack and not part of the Glenarm. Glenarm Group was deposited over Baltimore Gneiss.

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


Map showing publication footprint
  • Usage in publication:
    • Loch Raven Schist
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Piedmont-Blue Ridge province
Publication:

Muller, P.D., Candela, P.A., and Wylie, A.G., 1989, Liberty Complex; polygenetic melange in the central Maryland Piedmont, IN Horton, J.W., Jr., and Rast, Nicholas, eds., Melanges and olistostromes of the U.S. Appalachians: Geological Society of America Special Paper, 228, p. 113-134.


Summary:

Field and map relations suggest that Loch Raven Schist and Oella Formation are different lithofacies within same stratigraphic interval rather than two distinct stratigraphic units.

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


Map showing publication footprint
  • Usage in publication:
    • Loch Raven Formation
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Piedmont-Blue Ridge province
Publication:

Gates, A.E., Muller, P.D., and Valentino, D.W., 1991, Terranes and tectonics of the Maryland and southeast Pennsylvania Piedmont, IN Schultz, Art, and Compton-Gooding, Ellen, eds., Geologic evolution of the eastern United States; Field trip guidebook NE-SE GSA 1991: Virginia Museum of Natural History Guidebook, Joint meeting of Geological Society of America, Northeastern Section and Southeastern Section, no. 2, p. 1-27.


Summary:

Use of terms Wissahickon Group and Glenarm Supergroup discontinued in MD. Baltimore terrane cover sequence is described using individual formation names. Loch Raven Formation consists of two dominant lithologies: 1) medium to coarse-grained mica schist, interpreted as metapelite and 2) medium-grained gneiss, interpreted as metagraywacke (Oella Formation of Crowley, 1976). Minor amphibolite, micaceous quartzite, and marble also occur locally.

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


Map showing publication footprint
  • Usage in publication:
    • Loch Raven Schist*
  • Modifications:
    • Revised
    • Age modified
  • AAPG geologic province:
    • Piedmont-Blue Ridge province
Publication:

Drake, A.A., Jr., 1994, The Soldiers Delight Ultramafite in the Maryland Piedmont, IN Drake, A.A., Jr., and Pavlides, Louis, Stratigraphic notes, 1993: U.S. Geological Survey Bulletin, 2076-A, 14 p.


Summary:

Loch Raven Schist is here removed from Glenarm Group because current work shows that Loch Raven Schist is thrust over either Cockeysville Marble, Setters Formation, Baltimore Gneiss, or Laurel Formation. Soldiers Delight Ultramafite (new) lies tectonically between Loch Raven Schist and Sykesville Formation. Age of Loch Raven is here changed to Late Proterozoic and (or) Early Cambrian.

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


Search archives

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 ([ ]).

Accessibility FOIA Privacy Policies and Notices

USA Gov U.S. Department of the Interior | U.S. Geological Survey
Supported by the National Cooperative Geologic Mapping Program
Page Contact Information: Personnel
Page Last Modified: Thu 04 Apr 2024 03:24:49 PM MDT