Historical:Nutwood Shale Member
Elwood Atherton, Charles Collinson, and Jerry A. Lineback
Nutwood Shale Member of the Hannibal Shale (Workman and Gillette, 1956, p. 27) is named for Nutwood, Jersey County.
The type section of the Nutwood Shale Member is exposed along a creek through "The Narrows," just northeast of the village (SE NW 34, 8N-13W), where the Nutwood is 13 feet thick.
Extent and Thickness
The Nutwood occurs in a limited area from Calhoun County east to Christian County and south to Bond and northern St. Clair Counties. It is as much as 40 feet thick but is less than 20 feet thick within most of its extent.
The Nutwood is commonly in the lower part of the Hannibal, but in places it is at the base and rests on the "Glen Park" Formation or on Devonian strata.
The Nutwood is a silty, slightly calcareous or noncalcareous, dark brown to black, spore-bearing (Tasmanites) shale that grades laterally and vertically into gray Hannibal Shale.
WORKMAN, L. E., and TRACEY GILLETTE, 1956, Subsurface stratigraphy of the Kinderhook Series in Illinois: Illinois State Geological Survey Report of Investigations 189, 46 p.
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