Chana Member

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Lithostratigraphy: Ottawa Limestone Megagroup >>Platteville Group >>Pecatonica Formation >>Chana Member
Chronostratigraphy: Paleozoic Erathem >>Ordovician System >>Champlainian Series >>Blackriveran Stage
Allostratigraphy: Tippecanoe 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)

H. B. Willman and T. C. Buschbach


Original description

The Chana Member of the Pecatonica Formation (Templeton and Willman, 1963, p. 76).


Named for Chana, Ogle County, 9 miles east of the type section.

Other names


Type section

Type location

The type section of the Chana Member is located in a ravine (W 1/2 SE SE NE 24, 23N-9E) where it is 6.2 feet thick.

Type author(s)

Type status

Reference section

Reference location

Reference author(s)

Reference status

Stratigraphic relationships

Extent and thickness

In the northern outcrop area the Chana Member is commonly less than 5 feet thick, but it reaches 20 feet in southern Illinois.


In the northern area the Chana Member is largely brown, thick-bedded, vuggy, pure dolomite that contains disseminated sand grains and, in places, thin beds of sandstone of the St. Peter texture. The basal part commonly has slightly argillaceous or shaly beds and phosphatic pebbles. In southern Illinois it is largely pure, thick-bedded limestone.




Well log characteristics


Age and correlation

Environments of deposition

Economic importance



TEMPLETON, J. S., and H. B. WILLMAN, 1963, Champlainian Series (Middle Ordovician) in Illinois: Illinois State Geological Survey Bulletin 89, 260 p.

ISGS Codes

Stratigraphic Code Geo Unit Designation