Jersey County, Illinois, United States, North America
Accession Date:
29 Dec 2016
Collection Date:
19 Jul 1990
Notes:
L-118 (Chouteau Chert): Collection from a momdern quarry; Collection includes raw material, outer surface and surrounding matrix.
L-118 (Chouteau Chert)
Chouteau Chert, also known as Calhoun County Gray, is a course to fine grain and glossy chert. It has mottling of light and dark blues, resulting in mottled bluish gray, bluish black, and gray. When weathered it has a thick, white cortex. It has fossiliferous inclusions of crinoids, bryzoas, and brachiopods. Uniformly small crinoids, 2-3 mm, appear as white specks within the bluish, gray matrix. Deposits include lenticular, sub rectangular, or tabular module deposits.
Location remarks: Coon Creek, southeast of Rosedale, Jersey Co., Il; Truman Reservoir area southwest central Missouri along the edge of the Springfield Plateau, and along the Ozark Dome periphery in west central Missouri; southern Illinois River Valley; Chautauqua West, IL.
