Indian Run Formation (VACAi;0)

State	Virginia
Name	Indian Run Formation
Geologic age	Cambrian
Original map label	[i
Comments	Western Piedmont, Northern. From expanded explanation (ref. VA002): 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.
Primary rock type	melange
Secondary rock type
Other rock types
Lithologic constituents	Major Tectonite > Melange
Map references	Digital Representation of the 1993 Geologic Map of Virginia", 2003, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, viewing software not included. This is a digital version of "Geologic Map of Virginia" published in 1993. Available from: https://www.dmme.virginia.gov/commerce/ [https://www.dmme.virginia.gov/commerce/]
Unit references	Virginia Division of Mineral Resources, 1993, Geologic Map of Virginia: Virginia Division of Mineral Resources, scale 1:500,000 Digital Representation of the 1993 Geologic Map of Virginia - expanded explanation: 2003, Commonwealth of Virginia, Department of Mines, Minerals, and Energy, Divsion of Mineral Resources, Publication 147, 85 pp Digital Representation of the 1993 Geologic Map of Virginia", 2003, CD ROM (ISO-9660) contains image file, expanded explanation in pdf, and ESRI shapefiles, viewing software not included. This is a digital version of "Geologic Map of Virginia" published in 1993. Available from: https://www.dmme.virginia.gov/commerce/ [https://www.dmme.virginia.gov/commerce/]
Geographic coverage	Arlington - Fairfax