Exline Limestone Member

Lithostratigraphy: McLeansboro Group >>Modesto Formation >>Exline Limestone Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Desmoinesian 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 Exline Limestone Member of the Modesto Formation (Cline, 1941, p. 65-66).

Derivation

Named for Exline, Appanoose County, Iowa.

Type section

Type location

Exline is near the type section (SE 6, 67N-17W).

Stratigraphic relationships

In some places the Exline lies immediately on the Lonsdale Limestone, but in others it is as much as 30 feet above the Lonsdale.

Extent and thickness

The Exline occurs in western Illinois where it is dark gray to black, thin- and even-bedded limestone.

Lithology

In Illinois it usually is less than 3 feet thick, is underlain by black fissile shale, and is overlain by gray marine shale.

Fossils

It contains well preserved plant stems and leaves, the worm tube Spirorbis, and a few marine pelecypods (Wanless, 1957, p. 120). In Iowa, the Exline contains a normal marine fauna.

References

CLINE, L. M., 1941, Traverse of upper Des Moines and lower Missouri series from Jackson County, Missouri, to Appanoose County, Iowa: American Association of Petroleum Geologists Bulletin, v. 25, p. 23-72.
WANLESS, H. R., 1957, Geology and mineral resources of the Beardstown, Glasford, Havana, and Vermont Quadrangles: Illinois State Geological Survey Bulletin 82, 233 p.

ISGS Codes

Stratigraphic Code	Geo Unit Designation
2330	--