Kern County Regions

Kern County has many geological regions with much of the land finding its origins deep within the Pacific Ocean. The coast of California 200 million years ago was near the Nevada border. The current coast ranges are mostly uplifted from the ocean floor and consist mostly of sedimentary rock.

The rise of ocean sediments created the original Sierra Nevada. These sediments eventually eroded away and the parent rock changed from sedimentary material to become metamorphosed sedimentary rock. The tombstone rocks along the western Sierran foothills and the highly fractured reddish rocks found occasionally throughout the mountains are these metasediments. The Farallon Plate was a huge oceanic plate between the Pacific and North American Plates hundreds of millions of years ago. It was subducted under the North American plate between 30 million years ago  reducing the plate to liquid magma that hardened over millions of years to the granite now exposed all through the Sierra. There is a small remnant of the Farallon Plate now called the Juan de Fuca Plate that continues to be subducted along the coast of Northern California. Two other remnant sections, the Rivera and Cocos Plates, are found south of Baja California

At the junction of the Farallon and the North American Plates was the San Joaquin trench. This was the continental shelf before the breakup of Pangaea and sat where the western Sierra Nevada is today. The central valley is this deep trench that has been filled in with sediment from the Sierra Nevada, Transverse, and Coastal ranges.

LEGEND

Qa - Quaternary Alluvium - present to 1.8 mya (million years ago)

QPc - Quaternary Pliocene continental volcanic deposits - 1.8-5 mya

QPv - Quaternary Pliocene volcanic - 1.8-5 mya

Mm - Miocene marine - 5-24 mya

Em - Eocene marine - 34-56 mya

K _ Cretaceous marine - 65-145 mya

Ji - Jurassic intrusive rocks - 145-200 mya

Tv - Triassic volcanic - 200-250 mya

pf - Franciscan sedimentary and igneous rocks - 90-189 mya

pfi - Franciscan granite and intrusive rocks - 90-189 mya

MINING IN KERN COUNTY

Kern County's only major producing gold mine in 2002 was Glamis Rand Mining Company’s Rand Mine.

Rio Tinto’s Borax Mine and plant at Boron underwent a 12% increase in boron production in 2002. The overall price for all boron produced in California decreased by about 25% from 2001.

SOME RARE MINERALS OF KERN COUNTY

ALUNITE - Willow Springs, near Mojave

ANTIMONY (native) - Tom Moore Mine, Erskine Creek Mining District & near Kernville

CERVANTITE - Tom Moore Mine, Erskine Creek Mining District

GERSTLEYITE - Baker Mine, Boron & Western Mine, Kramer Borate District

HYDROBORACITE - Boron Mine, Boron

INDERITE - Boron Mine, Boron

INYOITE - Haulage Tunnel, Ryan & West Wall, Boron Mine, Boron

KERMESITE - Tom Moore Mine, Erskine Creek Mining District

KERNITE - B-Level Mudd Mine, Western Mine & Boron Mine, Boron

KURNAKOVITE - Boron Mine, Boron

MEYERHOFFERITE - Boron Mine, Boron

PARAREALGAR - Boron Mine, Boron

PROBERTITE - Western Mine, Boron, Kramer District

SASSOLITE - Mudd Mine, Boron

SENARMONTITE - Tom Moore Mine, Erskine Creek Mining District

SMYTHITE - Saddleback Basalt, Boron Mine, Boron

TUNELLITE (Barian) - Boron Open Pit & Boron Mine, Boron

VALENTINITE - Tom Moore Mine, Erskine Creek Mining District

Basic Geology       Kern County Biogeography       Indigenous Peoples of Kern County

Interior chaparral and woodlands     Great Valley Grassland     Great Basin Desert     Mojave Desert     Sierran Forest

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