Greenbrier Formation is here revised in western MD to include (ascending) Loyalhanna, Deer Valley, Savage Dam (new name), and Wymps Gap Members. In study area, typically characterized by high quartz sand content (locally >50%) and medium- to large-scale festoon cross-bedding. Thickness ranges from <20 to >30 ft. Lithology ranges from a sandy lime grainstone to a calcareous sandstone, green-gray to red-brown in color, and locally a gray marlstone. Commonly contains lower percentage of terrigenous quartz in western MD than in PA. Uppermost layer is tan argillaceous dolomitic siltstone or a red calcareous siltstone that allows easy recognition of contact with Deer Valley Member. Unconformably(?) overlies Purslane Formation. Age is Meramecian.
Source: GNU records (USGS DDS-6; Reston GNULEX).
Conodonts indicative of Chesterian faunas were recovered from the Loyalhanna Limestone Member of the Greenbrier Limestone in the Winchester 30 X 60 minute quadrangle.
Source: GNU records (USGS DDS-6; Reston GNULEX).
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