- Usage in publication:
-
- Ranger marble
- Modifications:
-
- Named
- Dominant lithology:
-
- Marble
- AAPG geologic province:
-
- Northern Rocky Mountain region
Summary:
No type locality designated. Is present at Brooklyn Ranger Station (source of the name), T16N, R79W, Albany Co, WY in the Northern Rocky Mountain region. Is a massive light- to dark-gray, fine-grained marble. Some jasper and some schistose beds included. Is 2,395 ft thick in a section measured on divide between Libby and French Creeks. Is younger than Anderson phyllite (new) and older than Towner greenstone (new). Assigned to the pre-Cambrian, early Algonkian or Proterozoic.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Ranger Marble
- Modifications:
-
- Not used
Summary:
A three-fold unit consisting of Nash Marble (oldest), Anderson Phyllite, and Ranger Marble (youngest) of Blackwelder (1926) is combined into one map unit named the Nash Fork Formation of the Libby Creek Group. Anderson Phyllite is a lenticular unit and cannot be traced beyond the Anderson mining prospect on Libby Creek, Albany Co, WY. Phyllites, which were the only lithology used to separate Nash from Ranger, occur at different stratigraphic levels in the Nash of Blackwelder. Locally, where marble and phyllite can be distinguished on the geologic map of this report, phyllite is shown as separate lithology and as part of the Nash Fork. Blackwelder's Nash, Anderson, and Ranger not used.
Source: GNU records (USGS DDS-6; Denver 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 ([ ]).