U.S. Borax open pit (Boron pit), U.S. Borax Mine (Pacific West Coast Borax; Pacific Coast Borax Co.; Boron Mine; Boron open pit; U.S. Borax and Chemical Corporation Mine; Kramer Mine; Kramer pit; Baker Mine), Kramer Borate deposit, Boron, Kramer District (Kramer Borate District), Kern Co., California, USA
|Latitude & Longitude (WGS84):||35° 2' 40'' North , 117° 41' 40'' West|
|Latitude & Longitude (decimal):||35.04444,-117.69444|
|Köppen climate type:||BWk : Cold desert climate|
The primary mineralization is borax, precipitated in a permanent shallow lake, fed from thermal (volcanic) springs rich in sodium & boron. Kernite was formed later upon deep (+1500 ft.) burial and temperatures above 53 deg. C (Christ and Garrels, 1959). The sodium borates together with claystone are hosted as a core facies within the Middle Miocene (16 mybp) Kramer beds (Barnard & Kistler, 1967) and are completely enveloped by ulexite-bearing shales (Gale, 1946). Stratigraphic and structural studies indicate the Kramer borates were deposited in a small structural, nonmarine basin, elongated in an east-west direction and limited on the south by the Western Borax fault.
[Joe Siefke 2010]
The open pit mine of the U.S. Borax Mine located in secs. 14 & 23, T11N, R8W, SBM, N of the town of Boron. A borate mine removing 10,000 tons/day during 1984. Owned by U.S. Borax & Chemical Corp.
In 1913 a borate mining claim was registered by O. Suckow, following identification of colemanite nodules during well drilling in the Kramer area of Kern Co. California.
This discovery claim was later bought out by the Pacific Coast Borax Company, whose subsequent exploration drilling in the district discovered the Na-borate deposit in 1925.
Their first exploitation was underground, via the shaft known as the Baker mine, which lies near the eastern end of the Na-borate ore body. During 1926 & 1927, two other companies, Suckow Borax Mines and the Western Borax Co., began working further west in the deposit. Both of these operations were taken over within the next few years by Pacific Coast Borax [Western Borax in 1933].
In the late 1940's the former Western Borax property was bought by the California Borate Co. which since seems to have faded from the scene, although I can find no reference to it's demise. In 1956 Pacific Coast Borax merged with United States Potash Corporation, to become US Borax, and in 1957 changed from underground to opencast working.
The Jenifer Mine was a shaft located about halfway between the Western Borax and Suckow Borax mines, and is now included within the US Borax property. In 1968 US Borax became part of the Rio Tinto Group.
Zeolites occur in basalt underlaying the borate deposit.
28 valid minerals. 1 (TL) - type locality of 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
|Holocene - Pliocene|
0 - 5.333 Ma
|Quaternary alluvium and marine deposits|
Age: Cenozoic (0 - 5.333 Ma)
Stratigraphic Name: Temescal Formation; Modesto Formation; Victor Formation; Alameda Formation; Aromas Red Sands; Bautista Beds; Brawley Formation; Borrego Formation; Burnt Canyon Breccia; Cabezon Fanglomerate; Campus Formation; Casitas Formation; Chemehuevi Formation; Corcoran Clay; Cushenbury Springs Formation; Dos Picachos Gravels; Dripping Springs Formation; Frazier Mountain Formation; Friant Formation; Harold Formation; Heights Fanglomerate; Hookton Formation (part); Huichica Formation; La Habra Formation; Manix Lake Beds; Mohawk Lake Beds; Montezuma Formation; Nadeau Gravel; Ocotillo Conglomerate; Orcutt Formation; Pacoima Formation; Pauba Formation; Peckham Formation; Pinto Formation; Resting Springs Formation; Riverbank Formation; Rohnerville Formation; San Dimas Formation; Shoemaker Gravel; Temecula Arkose; Battery Formation; Bay Point Formation; Colma Formation; Lindavista Formation; Lomita Marl; Merritt Sand; Millerton Formation; Palos Verdes Sand; San Pedro Formation; Sweitzer Formation; Timms Point Silt
Description: Alluvium, lake, playa, and terrace deposits; unconsolidated and semi-consolidated. Mostly nonmarine, but includes marine deposits near the coast.
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. 
Erd, R.C., V. Morgan & J.R. Clark (1961), Tunellite, a new hydrous strontium borate from the Kramer borate district, California: USGS PP 424-C, article No. 255: 294-297.
Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 102, 221, 228, 265, 283.
Morgan, V. and Erd, R.C. (1969) Minerals of the Kramer borate district, California California Division of Mines and Geology Mineral Information Service: 22: 152.
Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 246, 255.
Mining Annual Review (1985): 127.
Wise, W. S., & Kleck, W. D. (1988). Sodic clay-zeolite assemblage in basalt at Boron, California. Clays and Clay Minerals, 36(2), 131-136.
Tschernich, R. (1992): Zeolites of the World: 64, 311.
American Mineralogist (2005): 90: 1186-1191.