Bailey Limestone

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Lithostratigraphy: Hunton Limestone Megagroup >>Bailey Limestone
Chronostratigraphy: Paleozoic Erathem >>Devonian System >>Lower Devonian Series
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)

Charles Collinson and Elwood Atherton


Original description

The Bailey Limestone (Ulrich, in Buckley and Buehler, 1904, p. 110).


Named for Bailey's Landing on the Mississippi River, Perry County, Missouri, a settlement long abandoned but thought to have been at or near the village of Grand Eddy.

Other names

The Bailey Limestone has been traced widely in subsurface and referred to as the "unnamed limestone" (Collinson et al., 1967a).


Type section

Type location

As the original type section of the Bailey Formation is not exposed, Croneis (1944) designated as a neotype the outcrops in the river bluffs at and north of Red Rock Landing, half a mile east of Grand Eddy (11, 35N-12E).

Type author(s)

Type status

Reference section

Reference location

Reference author(s)

Reference status

Stratigraphic relationships

The Bailey is overlain conformably by the Grassy Knob Chert and in many localities is not readily differentiated from it (Weller et al., 1952; Pryor and Ross, 1962).

Extent and thickness

The Bailey Limestone underlies much of the deep part of the Illinois Basin and it has a maximum thickness of as much as 500 feet. It is 200-300 feet thick in the Illinois outcrop area, which extends from the south line of Jackson County to Olive Branch, Alexander County. It is exposed in high cliffs in the Mississippi River bluffs, especially in the Pine Hills area in Union County about 5 miles southeast of Grand Tower, where about 400 feet of Bailey, Grassy Knob, and Backbone is exposed (fig. D-3B).


The Bailey is dominantly gray to greenish gray, silty, cherty, thin-bedded, very hard limestone. Some beds are argillaceous. The chert is black to dark gray and occurs in bands of nodules and in beds, some of which are 1-2 feet thick. Beds of calcareous and silicified siltstone occur in places. In the northern area, bordering the Silurian reefs, the Bailey is less cherty and is greenish gray, argillaceous dolomite. An upper zone, 0-100 feet thick, is pure, white, coarsely crystalline, only slightly cherty limestone similar to the Backbone Limestone, from which it is separated by the Grassy Knob Chert.




Well log characteristics


The sparse fauna of the Bailey includes Leptaena rhomboidalis, Dalmanites sp. (pygidia), several species of rhynchonellid brachiopods, crinoids, and conodonts. Most of the fauna occurs in the upper part. The presence of Scyphocrinus elegans low in the formation has been interpreted as indicating that the lower part is uppermost Silurian in age and that no break in sedimentation occurred between the Silurian and Devonian Systems in this region.

Age and correlation

Environments of deposition

Economic importance

“Flat Gap limestone” is an informal name applied to producing zones between the Grassy Knob Chert (above) and the Bailey Limestone (below).

“Beaucoup” is an informal name applied to producing zones in the Bailey Limestone. It has been described in Collinson et. al (1967a) as

Unnamed Limestone Member of the Bailey Limestone
Over most of the central and western parts of the Illinois basin a grey to white, pure non-cherty limestone 10 to 40 feet thick occurs at the top of the Bailey. Because the unit is distinctive and identifiable over a large area, we have indicated it on our cross sections and stratigraphic col­umns (Figs. 3 and 7). Swann believes it may be a north­ward extension of the Flat Gap Limestone of Tennessee. In Washington County, Illinois, where it is especially well developed, it has been referred to by the oil field term "Beaucoup."
The unit is well exposed in Quarry Hill near Ozora, Ste. Genevieve County, Missouri, where it consists of 5 to 10 feet of heavily bedded grey-white encrinital limestone (Croneis, 1944).



BUCKLEY, E. R., and H. A. BUEHLER, 1904, Quarrying industry in Missouri: Missouri Bureau of Geology and Mines, v. 2, 371 p.
COLLINSON, CHARLES, L. E. BECKER, G. W. JAMES, J. W. KOENIG, and D. H. SWANN, 1967a, Illinois Basin, in International symposium on the Devonian System: Alberta Society of Petroleum Geologists, v. 1, p. 940-962; Illinois State Geological Survey Reprint 1968-G.
CRONEIS, C. G., 1944, Devonian of southeastern Missouri: Illinois State Geological Survey Bulletin 68, p. 103-131.
PRYOR, W. A., and C. A. ROSS, 1962, Geology of the Illinois parts of the Cairo, La Center, and Thebes Quadrangles: Illinois State Geological Survey Circular 332, 39 p.
WELLER, J. M., R. M. GROGAN, and F. E. TIPPIE, 1952, Geology of the fluorspar deposits of Illinois: Illinois State Geological Survey Bulletin 76, 147 p.

ISGS Codes

Stratigraphic Code Geo Unit Designation