- Usage in publication:
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- Peddicord Formation
- Modifications:
-
- Original reference
- Dominant lithology:
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- Silt
- AAPG geologic province:
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- Wisconsin arch
Summary:
Pg. 4. Peddicord Formation. Gray and pinkish tan, calcareous, lacustrine silts. Thickness 8 m. Recognized only in upper Illinois Valley. Overlies Sangamon Soil, Illinoian drift, or St. Peter Sandstone; underlies Robein Silt or Lee Center Till Member of Wedron Formation. Fossils. Age is Pleistocene (Wisconsinan Age; Farmdalian Subage).
Type section (see also Willman and Frye, 1970, p. 190): Wedron section, at the silica sand pit of Wedron Silica Company in Wedron, in SE/4 SW/4 sec. 9, T. 34 N., R. 4 E., Fox River valley, La Salle Co., northeastern IL. Named from Peddicord School, 1 mi east.
Source: Hdbk Illinois stratigraphy (Illinois Geol. Survey Bull. 95, p. 227); US geologic names lexicon (USGS Bull. 1520, p. 234-235).
- Usage in publication:
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- Peddicord Tongue*
- Modifications:
-
- Principal reference
- Revised
Summary:
Pg. 16-18, 32 (fig. 15), 53 (fig. 32), 57, 58. Peddicord Tongue of Equality Formation of Mason Group. A discontinuous subsurface unit of mostly silt and clay that extends beneath the Tiskilwa Formation of Wedron Group, the Ashmore Tongue of Henry Formation, or Morton Tongue of Peoria Silt. Peddicord Formation of Willman and others (1971) reallocated to Ashmore (coarse-grained) and Peddicord (fine-grained) Tongues.
Source: Publication.
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).