Historical:Briar Hill Coal Member
Lithostratigraphy: Kewanee Group >>Carbondale Formation >>Briar Hill Coal Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Desmoinesian Series
Allostratigraphy: Absaroka Sequence
M. E. Hopkins and J. A. Simon
The Briar Hill (No. 5A) Coal Member of the Carbondale Formation (Glenn, 1912, p. 38) is named for Briar Hill, a hill near Dekoven Station, Union County, Kentucky. The name was adopted in Illinois (Cady, 1919a, p. 20; 1926, p. 255). In Kentucky, this coal is now referred to as the No. 10 coal.
A locality in Saline County (9S-7E) was designated as representative of this coal for Illinois (Wanless, 1956, p. 10).
Extent and Thickness
In Illinois, the Briar Hill is fairly continuous in southeastern Illinois and has been recognized as far as Clark County on the northeast and Mt. Vernon on the northwest. It is generally thin and has been mined only on a small scale in the state. It extends into southwestern Indiana.
The coal is overlain by a dark gray to black shale that is fissile in places and is seldom over 2 feet thick. It is underlain by a hard silty underclay.
CADY, G. H., 1919a, Coal resources of District V (Saline and Gallatin Counties): Illinois State Geological Survey Mining Investigations Bulletin 19, 135 p.
CADY, G. H., 1926, Areal geology of Saline County: Illinois Academy of Science Transactions, v. 19, p. 250-272.
GLENN, L. C., 1912, A geological reconnaissance of the Tradewater River region, with special reference to the coal beds: Kentucky Geological Survey Bulletin 17, 75 p.
WANLESS, H. R., 1956, Classification of the Pennsylvanian rocks of Illinois as of 1956: Illinois State Geological Survey Circular 217, 14 p.
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