Gila Bend Mts, Maricopa Co., Arizona, USA
|Latitude & Longitude (WGS84):||33° 13' 21'' North , 113° 2' 14'' West|
|Latitude & Longitude (decimal):||33.22250,-113.03722|
|Other regions containing this locality:||Sonoran Desert, North America|
|Köppen climate type:||BWh : Hot deserts climate|
Ref.: Lopez, Robert, and Cameron, K. L. (1997) High-Mg andesites from the Gila Bend Mountains, southwestern Arizona; evidence for hydrous melting of lithosphere during Miocene extension. Geological Society of America Bulletin, July 1997: 109(7): 900-914.
Garvie, L.A.J. (2003) Decay-induced biomineralization of the saguaro cactus (Carnegiea gigantean). American Mineralogist: 88: 1879-1888.
Grant, Raymond W., Bideaux, R.A., and Williams, S.A. (2006) Minerals Added to the Arizona List 1995-2005: 4, 5, 6.
The Gila Bend Mountains are a mountain range with a maximum altitude of 1,581 feet (481.89 meters) above sea level.
Miocene andesites and basaltic andesites from the eastern Gila Bend Mountains have high Mg# values (most 66-72), high concentrations of Ni and Cr, and olivine phenocrysts as Mg rich as Fo90. The high-Mg andesites erupted near the end of Miocene extension in the Gila Bend region. The high-Mg andesites are interpreted to reflect hydrous melting of harzburgite near the base of mantle lithosphere at unusually low pressure. The low pressure was the result of tectonic thinning of the lithosphere during extension, and the source of the volatiles was most likely contemporaneous subduction. Although the Nd isotopic composition of the Gila Bend lavas originated from Proterozoic mantle lithosphere, the Pb isotope ratios mainly reflect the influence of Mesozoic and Cenozoic subduction. (This record excerpt provided courtesy of AGI/GeoRef).
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded from this region.
Mineral ListMineral list contains entries from the region specified including sub-localities
12 valid minerals.
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 Macrostrat.org
|Tortonian - Bartonian|
7.246 - 41.3 Ma
|Middle Miocene to Oligocene volcanic rocks|
Age: Cenozoic (7.246 - 41.3 Ma)
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)
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.