Historical:Davenport Member
Lithostratigraphy: Hunton Limestone Megagroup >>Wapsipinicon Limestone >>Davenport Member
Chronostratigraphy: Paleozoic Erathem >>Devonian System >>Middle Devonian Series
Allostratigraphy: Kaskaskia Sequence
Authors
Charles Collinson and Elwood Atherton
Name Origin
The Davenport Member of the Wapsipinicon Limestone is named for Davenport, Scott County, Iowa, near which it is exposed.
Type Section
No type section has be designated for the Davenport Member of the Wapsipinicon Limestone.
Other Names
As originally used, the name "Davenport" was applied to a Lower Davenport Member and an Upper Davenport Member. However, the upper, fossiliferous member was later assigned to the Cedar Valley, and the lower member was renamed the Davenport Member (Stainbrook, 1935).
Extent and Thickness
The Davenport is 40-50 feet thick in subsurface, but is 30 feet thick where exposed in the quarries at Milan and Rock Island and only 18 feet thick across the river near Linwood, Iowa.
Stratigraphic Position
The Davenport Member of the Wapsipinicon Limestone (Norton, 1894, p. 24; Stainbrook, 1935, p. 252), the uppermost member, overlies the Spring Grove Member and is overlain by the Cedar Valley Limestone.
Description
The Davenport Member consists of pure, hard, light gray to brownish gray, fine-grained to lithographic limestone. It contains many beds of limestone breccia and, in subsurface, anhydrite and gypsum.
Fossils
No fossils have been found in the Davenport Member.
References
NORTON, W. H., 1894, Notes on the lower strata of the Devonian Series in eastern Iowa: Iowa Academy of Science Proceedings 1, part 4, p. 22-24.
STAINBROOK, M. A., 1935, Stratigraphy of the Devonian System of the Upper Mississippi Valley: Kansas Geological Society Guidebook, 9th Annual Field Conference, p. 248-260.
ISGS Codes
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