Sylamore Sandstone
Lithostratigraphy: Knobs Megagroup >>New Albany Shale Group >>Sylamore Sandstone
Chronostratigraphy: Paleozoic Erathem >>Devonian System >>Upper 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 Sylamore Sandstone (Penrose, 1891b, p. 113, 114).
Derivation
Named for Sylamore Creek, Stone County, central northern Arkansas.
Other names
History/background
Type section
Type location
Type author(s)
Type status
Reference section
Reference location
Reference author(s)
Reference status
Stratigraphic relationships
The Sylamore Sandstone is the basal formation of the Upper Devonian Series in central and western Illinois (Workman and Gillette, 1956). In the western part of Illinois, it rests unconformably on the Middle Devonian Cedar Valley Formation or Wapsipinicon Limestone, on Silurian dolomite, or locally on Ordovician limestone. In eastern Illinois it probably is equivalent to thin sandy beds in the upper part of the Blocher Shale and the lower part of the Sweetland Creek Shale.
Extent and thickness
The Sylamore Sandstone is widely but sporadically present in Illinois, is rarely more than 5 feet thick, and generally varies from a few inches to a mere thin layer of sand embedded in the base of the Sweetland Creek Shale or the Grassy Creek Shale.
Lithology
The Sylamore Sandstone consists of well rounded, fine to medium, quartz sand grains, like those in the older Paleozoic sandstones. It varies from friable sandstone to grains cemented with pyrite, calcite, or dolomite.
Core(s)
Photograph(s)
Contacts
Well log characteristics
Fossils
Age and correlation
The Sylamore Sandstone is more or less continuous through Missouri, north and west of the Ozark Uplift, to the type locality, and it is correlated with the Hardin Sandstone east of the Ozarks in Kentucky and Tennessee.
Environments of deposition
Economic importance
Remarks
References
PENROSE, R. A. F., JR., 1891b, Manganese, its uses, ores, and deposits: Arkansas Geological Survey Annual Report 1890, 642 p.
WORKMAN, L. E., and TRACEY GILLETTE, 1956, Subsurface stratigraphy of the Kinderhook Series in Illinois: Illinois State Geological Survey Report of Investigations 189, 46 p.
ISGS Codes
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