Historical:Pokeberry Limestone Member

Lithostratigraphy: Kewanee Group >>Carbondale Formation >>Pokeberry Limestone Member
Chronostratigraphy: Paleozoic Erathem >>Pennsylvanian Subsystem >>Desmoinesian Series
Allostratigraphy: Absaroka Sequence

Authors

M. E. Hopkins and J. A. Simon

Name Origin

The Pokeberry Limestone Member of the Carbondale Formation (Wanless, 1939, p. 17, 98) is named for Pokeberry School, Schuyler County.

Type Section

Pokeberry School is near the type locality (NW 26, 2N-1W) (Wanless, 1956, p. 11; 1957, p. 113, 188).

Correlation

It was correlated by Wanless (1957, p. 113) with the Conant Limestone, but its position and correlation are uncertain. It may correlate with the Bankston Fork Limestone.

Extent and Thickness

The limestone is known only in the type area.

Stratigraphic Position

Where it is found, it is 15 feet above the Herrin Coal and 9 feet below the Danville (No. 7) Coal.

Description

It is a gray, dense, locally conglomeratic or brecciated limestone containing large fossils, most of them brachiopods. It has a very knobby upper surface. The Pokeberry Limestone is not shown on the geologic column (fig. P-2).

Fig. P-2 -- Classification of the Pennsylvanian System. In the graphic column, blank space indicates gray shale. Named members are listed to the right of the graphic column.

References

WANLESS, H. R., 1939, Pennsylvanian correlations in the Eastern Interior and Appalachian coal fields: Geological Society of America Special Paper 17, 130 p.
WANLESS, H. R., 1956, Classification of the Pennsylvanian rocks of Illinois as of 1956: Illinois State Geological Survey Circular 217, 14 p.
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
2590	--