Howardton Limestone Member

From ILSTRAT
Revision as of 12:51, 11 January 2017 by IlLex (talk | contribs) (Name)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Lithostratigraphy: Hunton Limestone Megagroup >>Lingle Formation
Chronostratigraphy: Paleozoic Erathem >>Devonian System >>Middle Devonian Series
Allostratigraphy: Kaskaskia 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

Name

Original description

The Howardton Limestone Member of the Lingle Formation (North, 1969, p. 22-25).

Derivation

Named for Howardton, Jackson County, 2 miles east of the type section.

Other names

History/background

Type section

Type location

The type section of the Howardton Limestone Member is located in a quarry in the Backbone ridge north of Grand Tower (NE NE SE 23, 10S-4W), where it is 33 feet thick.

Type author(s)

Type status

Reference section

Reference location

Reference author(s)

Reference status

Stratigraphic relationships

The Howardton Limestone Member of the Lingle Formation (North, 1969, p. 22-25) is the basal member of the Lingle Formation.

Extent and thickness

The Howardton extends throughout much of the area of the Lingle, but it is overlapped by the Tripp Member in the northern part. It is as much as 110 feet thick in southeastern Illinois and generally thins northward and westward.

Lithology

The Howardton is gray, fine-grained, slightly silty, argillaceous limestone, most of which has thin, shaly partings. The base of the Howardton is the original Grand Tower-Lingle contact of Savage (1920). The top of the Howardton is charaterized by a thin intraformational microbreccia with light-colored limestone fragments in a dark matrix.

Core(s)

Photograph(s)

Contacts

Well log characteristics

Fossils

The basal few feet of the Howardton is characterized by a small, button-shaped coral, Microcyclus.

Age and correlation

Environments of deposition

Economic importance

Remarks

References

NORTH, W. G., 1969, Middle Devonian strata of southern Illinois: Illinois State Geological Survey Circular 441, 45 p.
SAVAGE, T. E., 1920, Devonian formations of Illinois: American Journal of Science, v. 49, p. 169-182.

ISGS Codes

Stratigraphic Code Geo Unit Designation
6070
--