Shawangunk Formation

Shawangunk Formation

Stratigraphic range: Lower Silurian
Exposure of the Shawangunk at Lehigh Gap in Pennsylvania
TypeGeological formation
UnderliesBloomsburg Formation
OverliesMartinsburg Formation
Thicknessapprox. 1400 ft[1]
Lithology
Primaryquartzarenite (sandstone), conglomerate
Location
RegionAppalachian Mountains
ExtentPennsylvania, New Jersey, New York
Type section
Named forShawangunk Ridge
Named byW. W. Mather, 1840[2]
Cliff shaped by glacial movement surrounding the Mohonk Lake at Mohonk Mountain House on Shawangunk Ridge
Hand sample of the Shawangunk conglomerate from Blue Mountain, near New Tripoli, Pennsylvania

The Silurian Shawangunk Formation is a mapped bedrock unit in eastern Pennsylvania, New Jersey, and New York. It is named for the Shawangunk Ridge for which it is the dominant rock type. The division of the Shawangunk between the Tuscarora Formation and Clinton Group has not been conclusively determined. The shift of nomenclature currently has the divide between Hawk Mountain and Lehigh Gap.

  1. ^ Epstein, J.B., and Epstein, A.G., 1972, The Shawangunk Formation (Upper Ordovician (?) to Middle Silurian) in eastern Pennsylvania: U.S. Geological Survey Professional Paper 744, 45 p. [1]
  2. ^ Mather, W.W., 1840, Fourth annual report of the first geological district of the State of New York: New York Geological Survey Annual Report, no. 4, p. 209-258.