Historical:Walche Limestone Member
Lithostratigraphy: Pope Megagroup >>Menard Limestone >>Walche Limestone Member
Chronostratigraphy: Paleozoic Erathem >>Mississippian Subsystem >>Chesterian Series >>Elviran Stage
Allostratigraphy: Kaskaskia Sequence
Authors
Elwood Atherton, Charles Collinson, and Jerry A. Lineback
Name Origin
The Walche Limestone Member of the Menard Formation (Swann, 1963, p. 38-39) is named for Walche's cut on the Illinois Central Railroad in Caldwell County, Kentucky.
Type Section
The type section of the Walche Limestone Member is exposed at Walche's cut.
Other Names
Previously the Walche Limestone Member was called the "Little Menard."
Extent and Thickness
The Walche is 3-9 feet thick.
Stratigraphic Position
The Walche is overlapped by the Scottsburg Member, and it is not recognized north of a curve running approximately from northern Wabash County through Wayne County to southwestern Franklin County, beyond which it appears to grade laterally into siltstone that is included in the Waltersburg Formation.
Description
It is generally gray to dark gray limestone, typically silty or sandy, and pyritic in part.
References
SWANN, D. H., 1963, Classification of Genevievian and Chesterian (Late Mississippian) rocks of Illinois: Illinois State Geological Survey Report of Investigations 216, 91 p.
ISGS Codes
| Stratigraphic Code | Geo Unit Designation |
|---|---|