- Usage in publication:
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- River Falls Formation
- Modifications:
-
- Principal reference
- Dominant lithology:
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- Till
- Sand
- AAPG geologic province:
-
- Wisconsin arch
Summary:
Pg. 4 (table 1); App., p. A5-1 to A5-4. River Falls Formation. Previously called informal Baldwin till (Baker and Simpson, 1981, GSA Abs. w/ Prog., v. 13, no. 6, p. 270). Occurs in the Superior Lobe in Pierce, St. Croix, and Dunn Counties, western Wisconsin. Till is yellowish red to reddish brown, structureless sandy clay loam; locally in St. Croix County, upper part weakly stratified, containing lenses of fine sand. Thickness <1 to 10+ m. Overlies Hersey Member or Kinnickinnic Member of Pierce Formation (all new). Underlies till, sand, and gravel of the late Wisconsinan St. Croix moraine, or is exposed at the surface. Age is Pleistocene (Illinoian or early Wisconsinan).
Type section: south side of abandoned gravel quarry, 300 m south of County Trunk Highway E., about 2.5 mi (4 km) northeast of Baldwin, in SE/4 NE/4 NE/4 sec. 18, T. 29 N., R. 16 W., [approx. Lat. 45 deg. 00 min. 12 sec. N., Long. 92 deg. 21 min. 40 sec. W.], southern edge Emerald 7.5-min quadrangle, St. Croix Co., western WI.
Named from River Falls, River Falls West 7.5-min quadrangle, Pierce Co., western WI.
Reference section: west side of abandoned gravel pit, about 50 m south of Pleasant Valley Road, about 5 mi (8 km) southeast of River Falls, in SW/4 SW/4 NE/4 sec. 28, T. 27 N., R. 18 W., [approx. Lat. 44 deg. 47 min. 52 sec. N., Long. 92 deg. 34 min. 05 sec. W.], River Falls East 7.5-min quadrangle, Pierce Co., western WI.
[Additional locality information from Syverson and others, 2011, Wisconsin lexicon of Pleistocene units, Wisconsin Geol. Nat. Hist. Survey Tech. Rpt., no. 1; supplemented from USGS historical topographic map collection TopoView and Wisconsin Highways www.wisconsinhighways.org, accessed on June 9, 2018.]
Source: US geologic names lexicon (USGS Bull. 1565, p. 269).
- Usage in publication:
-
- River Falls Formation
- Modifications:
-
- Revised
- AAPG geologic province:
-
- Wisconsin arch
Summary:
Pg. vi (chart), 14-18. River Falls Formation. In western Wisconsin, River Falls Formation is revised to include Prairie Farm Member, a yellowish red to dark-brown till, <2 to 10 m thick. Age is considered Pleistocene (pre-Wisconsinan or early Wisconsinan).
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 ([ ]).