Mulberry Grove Silt Member

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Lithostratigraphy: Glasford Formation >>Mulberry Grove Silt Member
Chronostratigraphy: Cenozoic Erathem >>Quaternary System >>Pleistocene Series

Primary source

Willman, H. B., and John C. Frye, 1970, Pleistocene Stratigraphy of Illinois: Illinois State Geological Survey Bulletin 94, 204 p.

Contributing author(s)

H. B. Willman and John C. Frye


Original description

The Mulberry Grove Silt Member of the Glasford Formation was informally named the Mulberry Grove silt by Jacobs and Lineback (1969, p. 12) in the south-central Illinois region.


The Mulberry Grove Silt Member was named for Mulberry Grove, Bond County.

Other names


Type section

Type location

The type locality is the Mulberry Grove Section (Jacobs and Lineback, 1969, p. 21) in borrow pits just east of Mulberry Grove along Interstate Highway 70, SW SW Sec. 31, T. 6 N., R. 1 W., Fayette County.

Type author(s)

Type status

Reference section

Reference location

Reference author(s)

Reference status

Stratigraphic relationships

The Mulberry Grove Member is overlain by the Vandalia Till and underlain by the Smithboro Till Member. It appears to occur at approximately the same stratigraphic position as the Duncan Mills Member of central western Illinois.

Extent and thickness

The unit is generally less than 1.5 feet thick.


It is a thin, lenticular unit consisting mostly of calcareous silt, and locally contains a few fossil snail shells and lenses of sand and gravel.




Well log characteristics


Age and correlation

The Mulberry Grove Silt probably is within the early part of the Monican Substage of the Illinoian Stage.

Environments of deposition

Economic importance



JACOBS, A. M., and J. A. LINEBACK, 1969, Glacial geology of the Vandalia, Illinois, region: Illinois State Geological Survey Circular 442, 24 p.

ISGS Codes

Stratigraphic Code Geo Unit Designation