USGS

Metabasalt of the Catoctin Formation
Figure 9. A, Metabasalt of the Catoctin Formation (Zcm) showing flows interpreted to be overturned, with epidosite bodies that are separated from schistose metabasalt by tuffaceous phyllite and mud-lump breccia (Zct) in recessive interval. Outcrop is along Potomac River at Short Hill Mountain (pl. 1). Stick just right of center is 1 m long. B, Clast of metabasalt and beds of tuffaceous metarhyolite interbedded with tuffaceous phyllite and metabasalt of the Catoctin Formation along the Loudoun Heights trail on the Blue Ridge (p1. 1). Rock hammer is 28 cm long.
U.S. Geological Survey, U.S. Department of the Interior
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Contact: Scott Southworth
Last modified 08.29.00