Named for Collierstown, 8 mi west of Lexington, Rockbridge Co., western VA. In Shenandoah Valley, occurs in westernmost belt of Middle Ordovician limestone, along foot of Little North Mountain; is thicker and more widespread in middle and western belts of James River district. Consists of shell limestone and medium-grained calcarenite with intercalated buff argillaceous limestones and buff shales, some of which are probably metabentonites. Thickness mostly less than 75 ft; is 58 ft at type locality. Overlies Edinburg formation (new); underlies Martinsburg formation. Age is Middle Ordovician.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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