Grindstaff Sandstone Member
Lithostratigraphy: McCormick Group >>Abbott Formation >>Grindstaff Sandstone Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Atokan Series
Allostratigraphy: Absaroka Sequence
Primary source
Willman, H. B., Elwood Atherton, T. C. Buschbach, Charles Collinson, John C. Frye, M. E. Hopkins, Jerry A. Lineback, and Jack A. Simon, 1975, Handbook of Illinois Stratigraphy: Illinois State Geological Survey Bulletin 95, 261 p.
Contributing author(s)
M. E. Hopkins and J. A. Simon
Name
Original description
The Grindstaff Sandstone Member of the Abbott Formation (Butts, 1925, p. 44).
Derivation
Named for Grindstaff Hollow in Gallatin County.
Other names
History/background
Type section
Type location
Outcrops along Grindstaff Hollow (NE cor. 28, 10S-8E) are the type section.
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
Extent and thickness
The Grindstaff varies considerably in thickness up to 60 feet.
Lithology
The Grindstaff is similar in appearance and characteristics to the other two sandstones of the Abbott Formation in southern Illinois. It is best developed east of the Du Quoin Monocline. The Grindstaff is generally fine or medium grained, most of it is slightly micaceous. It sometimes contains quartz granules and pebbles in the western part of the southern Illinois outcrop belt but generally fewer than occur in the underlying Caseyville sandstones. The sandstone is thickest and coarsest where it was deposited in local distributary or fluvial channels. It grades laterally into and overlies gray, silty or sandy shale. In a few places a very impure, sandy, clastic limestone or calcareous sandstone, formerly called the Boskydell Marine Zone or Boskydell Sandstone, is found at or near the position of the Grindstaff Sandstone in southwestern Illinois.
Core(s)
Photograph(s)
Contacts
Well log characteristics
Fossils
Age and correlation
The Grindstaff Sandstone is correlated with the Babylon Sandstone of western Illinois.
Environments of deposition
Economic importance
Remarks
References
BUTTS, CHARLES, 1925, Geology and mineral resources of the Equality-Shawneetown area: Illinois State Geological Survey Bulletin 47, 76 p.
ISGS Codes
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