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Map showing publication footprint
  • Usage in publication:
    • Middlesex black shale
  • Modifications:
    • Named
  • Dominant lithology:
    • Shale
  • AAPG geologic province:
    • Appalachian basin
Publication:

Clarke, J.M., 1903, Classification of New York series of geologic formations: New York State Museum Handbook, no. 19, 28 p.


Summary:

Named Middlesex black shale for town of Middlesex, Middlesex Valley, Yates Co., NY. Unit is basal part of Naples beds in Ontario Co. It is overlain by Cashaqua shale and rests on Genesee shale and is considered of Late Devonian age.

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Middlesex Shale Member*
  • Modifications:
    • Areal extent
  • AAPG geologic province:
    • Appalachian basin
Publication:

de Witt, Wallace, Jr., and Roen, J.B., 1985, Correlation and geographic extent of some Middle and Upper Devonian and Lower Mississippian black shales in the Appalachian basin, IN Stratigraphic notes, 1984: U.S. Geological Survey Bulletin, 1605-A, p. A45-A57.


Summary:

Middlesex Shale Member of Sonyea Formation extended from southwestern NY into western PA and into subsurface in eastern OH, WV, and western MD.

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Middlesex Shale Member*
  • Modifications:
    • Overview
  • AAPG geologic province:
    • Appalachian basin
Publication:

de Witt, Wallace, Jr., Roen, J.B., and Wallace, L.G., 1993, Stratigraphy of Devonian black shales and associated rocks in the Appalachian basin, IN Roen, J.B., and Kepferle, R.C., eds., Petroleum geology of the Devonian and Mississippian black shale of eastern North America: U.S. Geological Survey Bulletin, 1909-B, p. B1-B57.


Summary:

In outcrop in western NY, the Sonyea consists of a basal black shale, the Middlesex Shale Member, and an upper gray shale with limestone nodules, the Cashaqua Shale Member. Members grade eastward into sequence of siltstone and silty shale, which is part of the general turbidite facies of the Catskill delta. The Middlesex is about 65 ft thick in the reference section 0.8 mi south of the village of Middlesex, Yates Co., NY. Thickens eastward to 75 ft at Chidsey Point Gully. Thins westward to 6 ft in Erie Co. Occurs in subsurface of PA, OH, WV, and MD, but apparently is not present in VA. Makes up most of the Sonyea in the subsurface. Age is Late Devonian.

Source: GNU records (USGS DDS-6; Reston GNULEX).


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For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates usage by the U.S. Geological Survey. Other usages by state geological surveys.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

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