Popes Head Formation - Station Hills Phyllite Member. Phyllite. (VAOCAps;0)

State	Virginia
Name	Popes Head Formation - Station Hills Phyllite Member. Phyllite.
Geologic age	Cambrian-Ordovician
Original map label	O[ps
Comments	Station Hills Phyllite Member; Western Piedmont, Northern. From expanded explanation (ref. VA002): Station Hills Phyllite. Light-greenish-gray, dusky yellow-weathering phyllite and lesser amounts of very-fine grained metasiltstone. Beds are 2 to 12 cm thick; many have thin basal intervals of graded siltstone. Mineralogy: muscovite + quartz + biotite + chlorite + plagioclase + magnetite + epidote. The top of the unit is nowhere exposed; maximum known thickness is 300 m. Some chlorite-rich phyllite is probably mafic metatuff; unit grades down into Old Mill Branch Metasiltstone.
Primary rock type	phyllite
Secondary rock type
Other rock types
Lithologic constituents	Major Metamorphic > Metasedimentary > Metaclastic > Phyllite
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", 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	Fairfax - Fairfax