Howardton Limestone Member
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
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