- Usage in publication:
-
- Iron King volcanics*
- Modifications:
-
- Named
- Dominant lithology:
-
- Basalt
- AAPG geologic province:
-
- Southwestern Basin-and-Range region
Summary:
Named as formation of Alder group of Yavapai series from exposures in Iron King Gulch, south of Humboldt, Yavapai Co, AZ, Southwestern Basin-and-Range region. No type locality designated. Crops out from southern boundary of map north for about 8,000 ft where it is covered by Cenozoic rocks. Are about 5,500 ft thick. The lower 4,500 to 5,000 ft is basalt and the upper part is andesitic tuffaceous sedimentary rock. Basalt is grayish green to greenish black; color dependent on whether mafic mineral is chlorite or actinolite hornblende, and on degree of foliation. Relict pillow structures. The andesitic tuffaceous rock is yellow to gray green, the texture is very fine to coarse grained, and has alternating fine-, medium-, and coarse-grained zones. Megascopic mineral content includes chlorite, sericite, epidote, quartz, and carbonate. Grades downward into the Spud Mountain volcanics (new) of Alder group. Are older Precambrian. Geologic map.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Iron King Volcanics*
- Modifications:
-
- Revised
- AAPG geologic province:
-
- Southwestern Basin-and-Range region
Summary:
Are removed from abandoned Alder Group of Yavapai Series. Is top formation of newly named Big Bug Group. Occurs in Mount Union and Mayer quads, Yavapai Co, AZ in the Southwestern Basin-and-Range region. Geologic map. Precambrian age.
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 ([ ]).