Indian Run Formation

Indian Run Formation (Drake, 1985). Poorly- to well foliated metasedimentary melange consisting of a medium grained quartz-plagioclase-muscovite-biotite-chlorite-garnet matrix containing quartz "eyes" and a heterogeneous suite of olistoliths. These include: foliated Accotink Schist and Lake Barcroft Metasandstone, and foliated ultramafic, metagabbroic, and felsic and mafic metavolcanic rocks. The Indian Run predates Occoquan Granite.
State Virginia
Name Indian Run Formation
Geologic age Cambrian
Lithologic constituents
Tectonite > Melange
Comments Western Piedmont (Northern)

Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000.

Virginia Division of Mineral Resources, 2003, Digital Representation of the 1993 Geologic Map of Virginia, Publication 174, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, scale 1:500,000.

NGMDB product
Counties Arlington - Fairfax