Wilcox Formation

Wilcox Formation
Stratigraphic range: Middle Proterozoic
TypeFormation
Unit ofMount Holly Complex
Thickness915 meters (3,002 ft)
Location
RegionVermont
Country United States
Type section
Named forWilcox Hill, Rutland County, Vermont[1]
Named byBrace (1953)[1]

The Wilcox Formation is a geologic formation in Vermont that is part of the Holly Mountain Complex. It is exposed within the western parts of Mendon and Shrewsbury, Vermont. The type locality of the Wilcox Formation lies on the slopes south of Cold River of the eponymous Wilcox Hill and on northwest slope of Mendon Peak.[1][2]

The Wilcox Formation consists primarily of dark-gray to brownish-gray, muscovite rich, chlorite-quartz schist. The schist is locally interbedded with either beds of chlorite-spotted, vitreous quartzite too small to map or prominent beds of vitreous quartzite as much as 10 meters (33 ft) thick. This formation has a distinctive shredded, schistose appearance because of closely-spaced foliation and rusty-weathering cleavage. Elsewhere within the Wilcox Formation, thin beds of white graphite-dolomite marble, and retrograded deep-orange-to tan-weathering dolomite are common. At the type locality on Wilcox Hill and on the slopes south of Cold River, the schist contains pods of aplitic gneiss and veins rich in tourmaline.[1][2][3]

  1. ^ a b c d Brace, W.F., 1953. The geology of the Rutland area, Vermont. Vermont Geological Survey Bulletin. 6, 120 pp. , 1 map, scale 1:62,500.
  2. ^ a b Ratcliffe, N.M., 1994. The Wilcox Formation of Vermont Assigned to the Mount Holly Complex. United States Geological Survey Bulletin, 2060, p.11-18.
  3. ^ Ratcliffe, N.M., 1998. Digital and preliminary bedrock geologic map of the Rutland quadrangle, Vermont. United States Geological Survey Open-File Report, 98-121-A, 1 plate, scale 1:24000.