H. B. Willman and T. C. Buschbach
The Mincke Member of the Kings Lake Formation (Templeton and Willman, 1963, p. 111), the lower member, is named for Mincke Hollow, a small tributary of the Meramec Valley in St. Louis County, Missouri.
The mouth of Mincke Hollow is a quarter of a mile southwest of the Mincke Member type section, which is in a railroad cut in the Meramec Valley bluff (near cen. E1/2 SE SE 21, 44N-4E), where the member is 6.3 feet thick.
Extent and Thickness
In Illinois the Mincke Member is exposed only near West Point Landing, Calhoun County. The Mincke Member thins northward from the type section to 4.9 feet in the Kings Lake type section and 3.6 feet at New London, Missouri.
The Mincke Member consists of interbedded 1-5 inch beds of (1) silty argillaceous limestone that locally contains a small amount of fine sand, (2) very fossiliferous calcarenite, and (3) green to brown shale. A bed of yellow bentonite 0.5-2 inches thick is persistent in a bed of brown shale 1-1.5 feet below the top.
TEMPLETON, J. S., and H. B. WILLMAN, 1963, Champlainian Series (Middle Ordovician) in Illinois: Illinois State Geological Survey Bulletin 89, 260 p.
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