- Usage in publication:
-
- Duppa Member*
- Modifications:
-
- First used
- AAPG geologic province:
-
- Plateau sedimentary province
Summary:
First use of the Duppa Member of the Galeros Formation of the Chuar Group. Marks a return to the argillaceous character of the of the Galeros, with only a few thin scattered limestone beds over a thickness of 570 ft. Siltstone beds up to 3 ft thick are scattered throughout, and toward the top there are thin hematite-cemented sandstones, with well-rounded grains. The rest is shale, generally micaceous, grading into red mudstones toward the top. Age is late Precambrian.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Duppa Member
- Modifications:
-
- Named
- Dominant lithology:
-
- Shale
- Limestone
- Siltstone
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
Named as the upper member of Galeros Formation of Chuar Group for Chuar Butte, west side Colorado River, Coconino Co, AZ in Southern Rocky Mountain region. Type section is below Duppa Butte in Kwagunt Canyon. Overlies Carbon Canyon Member (new) of Galeros. Base of Duppa placed at highest limestone more than 3 ft thick. Underlies Carbon Butte Member (new) of Kwagunt Formation (new) of Chuar. Composed of purple to gray micaceous shale, thin beds of limestone, and calcareous siltstone. No complete section measured. Is 570 ft thick at type, 532 ft thick on west slope Carbon Butte, and about 460 ft thick south of campsite in Nankoweap Canyon. Probably was the Divisions 1 and 2 of Walcott (1899) and Hinds (1935) Division 5. Of late Precambrian age. Geologic map.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Duppa Member*
- Modifications:
-
- Adopted
- AAPG geologic province:
-
- Plateau sedimentary province
Summary:
Duppa Member of the Galeros Formation of the Chuar Group of Ford and Breed (1973) is adopted as the Duppa Member of the Galeros Formation of the Chuar Group of the Grand Canyon Supergroup. Age is late Precambrian.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Duppa Member*
- Modifications:
-
- Age modified
- AAPG geologic province:
-
- Plateau sedimentary province
Summary:
Age of the Duppa Member of the Galeros Formation is modified from late Precambrian to: Proterozoic Y.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Duppa Member*
- Modifications:
-
- Age modified
- AAPG geologic province:
-
- Southern Rocky Mountain region
Summary:
Is the upper member of Galeros Formation of Chuar Group of Grand Canyon Supergroup. Underlies Carbon Butte Member of Kwagunt. Age designation of Proterozoic Y changed to Late Proterozoic, the age term applied to rocks younger than 900 Ma and older than 570 Ma. Change in age designation made to Galeros and its Tanner (base), Jupiter, Carbon Canyon, and Duppa Members in the Southern Rocky Mountain region of northern AZ. Is 104 m thick. Columnar section.
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 ([ ]).