- Usage in publication:
-
- Roosevelt member [formation]
- Modifications:
-
- Original reference
- Dominant lithology:
-
- Shale
- Chert
- AAPG geologic province:
-
- Southwestern Basin-and-Range region
Summary:
Pg. 32. Roosevelt member [formation] of Apache group. Seventh [upper] member of group. Chert and dark-reddish and purplish siliceous shales. Maximum thickness 30 feet. Underlies Troy quartzite and overlies a vesicular basalt flow south of Roosevelt Dam. Age is Precambrian (Algonkian).
[Present locally at and near Roosevelt Dam, Gila Co., south-central AZ.]
Source: US geologic names lexicon (USGS Bull. 1200, p. 3336); GNC index card files (USGS-Reston).
- Usage in publication:
-
- Roosevelt Member [Formation]†
- Modifications:
-
- Abandoned
- AAPG geologic province:
-
- Southwestern Basin-and-Range region
Summary:
Pg. 8-9 (table 1), 42. †Roosevelt Member [Formation] of Apache Group of Hinds (1935) abandoned. Rocks included in unnamed argillite member at top of Mescal Limestone of Apache Group.
[Author states Hinds used the term "member" in a formational sense.]
Source: Publication; GNC index card files (USGS-Reston).
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 ([ ]).