Sorento Limestone Member

Lithostratigraphy: McLeansboro Group >>Bond Formation >>Sorento Limestone Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Missourian 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 Sorento Limestone Member of the Bond Formation (Simon, in Wanless, 1955, p. 1764).

Derivation

Named for Sorento, Bond County.

Type section

Type location

The type section consists of outcrops along the south-flowing tributary of Dry Fork just southwest of Sorento (NE NE 6, 6N-4W) (Kosanke et al., 1960, p. 39).

Stratigraphic relationships

In southwestern Illinois the Sorento generally lies 15-20 feet above the Shoal Creek Limestone. In the deeper part of the Illinois Basin the interval is usually 20-40 feet, but locally it may be as much as 100 feet.

Extent and thickness

The Sorento Limestone and the underlying unnamed coal have been recognized throughout much of the Illinois Basin. The Sorento is less than 2 feet thick.

Lithology

The limestone is generally fine grained and medium gray.

Fossils

It contains an open-marine fauna composed primarily of brachiopods, crinoids, and gastropods.

Age and correlation

The Sorento is tentatively correlated with the Little Vermilion Limestone of northern Illinois.

References

KOSANKE, R. M., J. A. SIMON, H. R. WANLESS, and H. B. WILLMAN, 1960, Classification of the Pennsylvanian strata of Illinois: Illinois State Geological Survey Report of Investigations 214, 84 p.
WANLESS, H. R., 1955, Pennsylvanian rocks of Eastern Interior Basin: American Association of Petroleum Geologists Bulletin, v. 39, p. 1753-1820 (see 1962).

ISGS Codes

Stratigraphic Code	Geo Unit Designation
2050	--