Purcell Knob
Encyclopedia
Purcell Knob is a spur of the Blue Ridge Mountain
in Loudoun County, Virginia
. The 1207 feet (367.9 m) peak is just northeast of the main ridge at Keyes Gap
and southeast of the village of Neersville
.
Purcell Knob is notable for exposure of the sericitic phyllite
base of the paleozoic
Loudoun Formation
in its antiformal syncline
Blue Ridge Mountain
Blue Ridge Mountain, also known as Blue Mountain, is the colloquial name of the western most ridge of the Blue Ridge Mountains in northern Virginia and the Eastern Panhandle of West Virginia...
in Loudoun County, Virginia
Loudoun County, Virginia
Loudoun County is a county located in the Commonwealth of Virginia, and is part of the Washington Metropolitan Area. As of the 2010 U.S. Census, the county is estimated to be home to 312,311 people, an 84 percent increase over the 2000 figure of 169,599. That increase makes the county the fourth...
. The 1207 feet (367.9 m) peak is just northeast of the main ridge at Keyes Gap
Keyes Gap
Keyes Gap or Keyes' Gap is a wind gap in the Blue Ridge Mountain on the border of Loudoun County, Virginia and Jefferson County, West Virginia. The gap is traversed by Virginia State Route 9/West Virginia State Route 9. The Appalachian Trail also crosses the gap.-History:Originally known as...
and southeast of the village of Neersville
Neersville, Virginia
Neersville is an unincorporated community in northwestern Loudoun County, Virginia, USA. It is located in the Between the Hills area of the Loudoun Valley on Harpers Ferry Road at the foot of Short Hill Mountain...
.
Purcell Knob is notable for exposure of the sericitic phyllite
Phyllite
Phyllite is a type of foliated metamorphic rock primarily composed of quartz, sericite mica, and chlorite; the rock represents a gradation in the degree of metamorphism between slate and mica schist. Minute crystals of graphite, sericite, or chlorite impart a silky, sometimes golden sheen to the...
base of the paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
Loudoun Formation
Chilhowee formation
The Chilhowee Group is a sedimentary body composed of early Cambrian siliciclastic sedimentary rocks which crop out along the eastern margin of the Blue Ridge province in Maryland and Virginia...
in its antiformal syncline