Donate now to keep alive!Help|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on Mindat
What is a mineral?The most common minerals on earthMineral PhotographyThe Elements and their MineralsGeological TimeMineral Evolution
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Kofa Mts (S.H. Mts), Yuma Co., Arizona, USA

This page is currently not sponsored. Click here to sponsor this page.
Latitude & Longitude (WGS84): 33° 19' 48'' North , 113° 57' 10'' West
Latitude & Longitude (decimal): 33.33000,-113.95278
Other regions containing this locality:Sonoran Desert, North America
Köppen climate type:BWh : Hot deserts climate

A mountain range located 20 miles SE of Quartzsite and NE of the Castle Dome Moutnains. The alternate name of S.H. Mountains which allegedly stands for 'Stone House.'

This is an isolated mountainous area in the central part of Yuma County. They cover an area of approximately 200 square miles are are surrounded by broad, gently-aggraded plains that separate them from other detached mountains. The higher summits rise probably 2,000 feet above the surrounding plains.

These mountains are composed of extrusive igneous rocks which rest on an eroded surface of much older rocks. These older rocks are exposed in low foothills in the northern and southern parts of the mountainous area. The volcanic rocks are probably of tertiary and Quaternary age. The older rocks consist of metamorphosed sediments with associated pegmatites, thought to be of Precambrian age, intruded by granite and dike rocks of probable Mesozoic age. These rocks are intricated dissected into flat-topped mesas of small extent or into jagged spires and other fantastic erosional forms.

Mineralization is Au-Cu-Pb deposits that occur in certain fault zones. The bulk of these mountains consists of a gently Northward dipping block of Tertiary rhyolites, andesites and tuffs, capped by basalts, that rises to more than 4,000 feet above sea level, or 2,500 feet above the adjacent plains. Minor areas of schist, granite, and shales are exposed at the base of the volcanics. The granite is of interest since it contains copper deposits. Extensive faulting and fracturing have affected all of the rocks, particularly those of the pre-lava age.

Commodity List

This is a list of exploitable or exploited mineral commodities recorded from this region.

Mineral List

Mineral list contains entries from the region specified including sub-localities

27 valid minerals.

Rock Types Recorded

Note: this is a very new system on and data is currently VERY limited. Please bear with us while we work towards adding this information!

Rock list contains entries from the region specified including sub-localities

Select Rock List Type

Alphabetical List Tree Diagram

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on

Tortonian - Bartonian
7.246 - 41.3 Ma

ID: 2939106
Middle Miocene to Oligocene volcanic rocks

Age: Cenozoic (7.246 - 41.3 Ma)

Stratigraphic Name: Peach Springs Tuff; Apache Leap Tuff

Description: Lava, tuff, fine-grained intrusive rock, and diverse pyroclastic rocks. These compositionally variable volcanic rocks include basalt, andesite, dacite, and rhyolite. Thick felsic volcanic sequences form prominent cliffs and range fronts in the Black (Mohave County), Superstition, Kofa, Eagletail, Galiuro, and Chiricahua Mountains. This unit includes regionally extensive ash-flow tuffs, such as the Peach Springs tuff of northwestern Arizona and the Apache Leap tuff east of Phoenix. Most volcanic rocks are 20-30 Ma in southeastern Arizona and 15 to 25 Ma in central and western Arizona, but this unit includes some late Eocene rocks near the New Mexico border in east-central Arizona. (11-38 Ma)

Lithology: Major:{basalt,andesite,dacite}, Minor:{rhyolite}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]

Data and map coding provided by, used under Creative Commons Attribution 4.0 License

Localities in this Region

This page contains all mineral locality references listed on This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.


Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Jones, E.L., Jr. (1915), A Reconnaissance in the Kofa Mountains, Arizona, USGS Bull. 620: 151-164.
Wilson, E.D. (1933) Geology and Mineral Deposits of Southern Yuma County, Arizona. Arizona Bureau of Mines Bulletin 134: 106-109.
Walker, L.W. (1957), The geodes of Kofa, Nature: 50: 266-267.
Dale, V.B. (1959), Tungsten deposits of Yuma, Maricopa, Pinal, and Graham Counties, Arizona, U.S. Bureau of Mines Report of Investigation 5516.
Dahm, J.B., and Hankins, D.D. (1982) Preliminary geology of a portion of the southern Kofa Mountains, Yuma County, Arizona, in Frost, E.G., and Martin, D.L., eds., Mesozoic-Cenozoic tectonic evolution of the Colorado River region, California, Arizona, and Nevada - Anderson-Hamilton Volume: San Diego, Cordilleran Publishers, p. 459-469.
Hankins, D.D. (1984) Geologic map of a portion of the southern Kofa Mountains, Arizona: Arizona Bureau of Geology and Mineral Technology Miscellaneous Map MM-84-A, 1 sheet, scale 1:12,000.
Hankins, D.D. (1984) Geologic setting of precious metals mineralization, King of Arizona district, Kofa Mountains, Yuma County, Arizona: San Diego, San Diego State University, M.S. thesis, 135 p., 1 sheet, scale 1:12,000.
Charlton, D.W., Copeland, D.J., Reaugh, L.W., and Westall, N.D. (1985) Gold mineralization in low angle faults, Verdstone property, Kofa Mountains, Arizona [abs.]: Geological Society of America Abstracts with Programs: 17(6): 348.
Blair, Gerry (1992), The Rockhound's Guide to Arizona: Helena, MT, Falcon Press: 157.
Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 236, 349, 364.
Ferguson, C.A., and Skotnicki, S.J. (1996) Geology of the northern Kofa Mountains (Owl Head and northern third of the Kofa Butte 7.5' quadrangles), Yuma and La Paz Counties, Arizona: Arizona Geological Survey Open-File Report 96-03, 22 p., 2 sheets, scale 1:24,000.
Skotnicki, S.J., and Ferguson, C.A. (1996) Geology of the Cholla Tank and northern third of the Hoodoo Well quadrangles), northern Kofa Mountains, Yuma and La Paz Counties, Arizona: Arizona Geological Survey Open-File Report 96-24, 11 p., 1 sheets, scale 1:24,000.

Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © and the Hudson Institute of Mineralogy 1993-2018, except where stated. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: February 24, 2018 06:21:34 Page generated: January 27, 2018 21:55:09
Go to top of page