Dykersburg Shale Member

Revision as of 22:28, 25 January 2017 by IlLex (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Lithostratigraphy: Kewanee Group >>Carbondale Formation >>Dykersburg Shale 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


Original description

The Dykersburg Shale Member of the Carbondale Formation (Hopkins, 1968, p. 4).


Named for Dykersburg (called Absher on some maps), Williamson County.

Other names


Type section

Type location

Dykersburg is near the type section which is in the highwall of an abandoned coal strip pit (SE SE NE 34, 9S-4E).

Type author(s)

Type status

Reference section

Reference location

Reference author(s)

Reference status

Stratigraphic relationships

Extent and thickness

The Dykersburg is confined to a belt 3-15 miles wide that extends southwestward from Wabash County to the outcrop in Saline County. The Dykersburg is as much as 100 feet thick in places.


Most of it is gray silty shale containing some sandstone, particularly one major channel sandstone that replaces the Harrisburg Coal along a narrow band. Where overlain by the Dykersburg Shale, the Harrisburg Coal is thicker, is commonly characterized by several shale splits, and contains much less sulfur (less pyrite) than in areas where it is overlain by black fissile shale or the St. David Limestone. The Dykersburg is also well developed in an adjacent area in western Indiana.




Well log characteristics


Age and correlation

Environments of deposition

Economic importance



HOPKINS, M. E., 1968, Harrisburg (No. 5) Coal reserves of southeastern Illinois: Illinois State Geological Survey Circular 431, 25 p.

ISGS Codes

Stratigraphic Code Geo Unit Designation