The Chilhowee Group is a
sedimentary body composed of early
Cambrian
The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...
siliciclastic sedimentary rocks which crop out along the eastern margin of the
Blue Ridge province in
Alabama,
Maryland,
Tennessee,
North Carolina,
Virginia, and
West Virginia. They represent a
rift to
passive margin sequence, with mostly coarse,
feldspathic sandstones and
conglomerates in the lower member and
shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...
s and
phyllite in the upper members. The Chilhowee Group contains four formations; the Loudoun Formation,
Weverton Formation,
Harpers Formation
The Harpers Formation is a geologic formation in Maryland, Pennsylvania, Virginia, and West Virginia, consisting of schist, phyllite, and shale. It dates back to the early Cambrian period. It is considered part of the Chilhowee Group.
Notable ex ...
and
Antietam Formation. Another name for the Harpers formations is the Hampton formation, and the Antietam Formation is also known as the Erwin Formation. The Hampton Formation has minor economic importance in the area near the James River Face Wilderness. As of 1982 there were three quarries operating near the James River Face Wilderness. Those quarries produced roofing shale, light weight aggregate, and various materials for brick making. The Antietam Formation also had a minor economic importance, particularly from 1945 up until 1966. There were three quarries producing crushed quartzite, which was used to produce concrete aggregates, road metal and railroad ballast.
References
Cambrian System of North America
Blue Ridge Mountains
Cambrian West Virginia
{{US-geologic-formation-stub