- Usage in publication:
-
- Pence ferruginous slate member
- Modifications:
-
- Named
- Dominant lithology:
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- Slate
- AAPG geologic province:
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- Wisconsin arch
Summary:
Named the Pence ferruginous slate member of the Ironwood formation for Pence mine, Iron Co., WI. Consists of dominantly thin- and even-bedded ferruginous slate with a flatwise conglomerate at base of member. Thickness is 80 to 130 feet. Unit unconformably overlies the Norrie ferruginous chert member and underlies the Anvil ferruginous chert member, both of the Ironwood formation. The Pence is of Precambrian age.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Pence Member*
- Modifications:
-
- Revised
- AAPG geologic province:
-
- Wisconsin arch
Schmidt, R.G., and Hubbard, H.A., 1972, Penokean orogeny in the central and western Gogebic region, Michigan and Wisconsin: [unknown]
Summary:
Revised the Pence to the Pence Member of the Ironwood Iron-Formation. Consists mostly of thin-bedded cherty carbonate iron-formation. Unit overlies the Norrie Member and underlies the Anvil Member of the Ironwood Iron-Formation. The Pence is of Precambrian X age.
Source: GNU records (USGS DDS-6; Reston GNULEX).
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 ([ ]).