New Albany Shale
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The New Albany Shale is an organic-rich geologic formation of Devonian and Mississippian age in the Illinois Basin of the United States. It is a major source of hydrocarbons.
The New Albany formation consists of brown, black, and green shale with minor beds of dolomite and sandstone. It was deposited under anoxic marine conditions. Pyrite is a common accessory mineral, and parts of the shale have greater than 4% by weight of organic carbon. The black shale layers have anomalously high radioactivity (due to uranium), phosphorus, and heavy metals. The formation was named for outcrops near New Albany, Indiana. It is one of a number of organic-rich shales of upper Devonian and lower Mississippian age in North America. It is correlative with the Antrim Shale of the Michigan Basin, the Ohio Shale of Ohio and eastern Kentucky, and the Chattanooga Shale of Tennessee and central Kentucky.
The formation is composed of six members. These members in ascending stratigraphic order are the Blocher, the Selmier, the Morgan Trail, the Camp Run, the Clegg Creek and the Ellsworth. The Blocher consists of brownish-black to grayish-black, slightly calcareous pyritic shale. The Selmier is a greenish-gray to olive-gray shale. The Morgan Trail is a brownish-black to olive-black fissile siliceous pyritic shale. The Camp Run is a greenish-gray to olive-gray shale interbedded with brownish-black shale. The Clegg Creek is a brownish black pyritic shale that is rich in organic matter. The Ellsworth is composed of a lower part of interbedded brownish-black shale and an upper part of greenish-gray shale.
- ↑ Frank R. Ettensohn and Lance S. Barron, 1981, Depositional model for the Devonian-Mississippian black-shale sequence of North America: a tectono-climatic approach, US Dept. of Energy, DOE/METC/12040-2, PDF file.
- ↑ Indiana Geologic Survey, 1997, "New Albany Shale"