Geology topics

Research about Kern County, San Bernardino County, California

Source-linked reports with geographic coverage including Kern County, San Bernardino County, California.

3 recordsLinked to original sources

USGS2023

Preliminary surficial geologic map of Leuhman Ridge and the surrounding area, Edwards Air Force Base and Air Force Research Laboratory, Kern and San Bernardino Counties, California

This preliminary geologic map presents mapping of the Leuhman Ridge area of Edwards Air Force Base, California, conducted between April 2020 and June 2021. The report focuses on surficial materials and bedrock to evaluate potential faults and other geologic features that may influence groundwater movement. The preliminary work confirms that the Spring Fault, previously mapped by Dibblee (1960, 1967), is a Quaternary-active fault but does not find convincing evidence to support the existence of the Leuhman Fault (Dibblee, 1960; 1967) within the map area. Several more possible and probable faults are identified by a combination of geomorphic lineaments and brecciated rock. Pleistocene and Holocene eolian deposits are widespread, manifesting as sand sheets, dunes, and admixtures into alluvial fans. Also, an incised pediment forms much of the upland south of Leuhman Ridge. In general, field observations indicate that Quaternary alluvial and eolian deposits are thin; this suggests that secondary bedrock porosity and permeability, defined by degree of weathering and fracture density that includes fault-related fracturing, are more important factors in the location and flow patterns of groundwater.

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USGS2012

Surficial geologic map of the Cuddeback Lake 30' x 60' quadrangle, San Bernardino and Kern Counties, California

The 1:100,000-scale Cuddeback Lake quadrangle is located in the western Mojave Desert north-northeast of Los Angeles, between the southern Sierra Nevada and San Bernardino Mountains, in Kern and San Bernardino Counties, California. Geomorphic features include high-relief mountains, small hills, volcanic domes, pediments, broad alluvial valleys, and dry lakes. It is one in a series of surficial geologic maps created to investigate landscape development and tectonic evolution of the northern Mojave Desert. The mapped area includes pre-Tertiary plutonic, metavolcanic, metasedimentary, and igneous rocks; Tertiary sedimentary and volcanic rocks; and Quaternary sediments and basalts. The map area includes the El Paso, Lockhart, Blackwater, and Muroc Faults, as well as the central segment of the Garlock Fault Zone. The tectonically active western Mojave Desert and the variety of surficial materials have resulted in distinctive geomorphic features and terrains. Geologic mapping shows that active faults are widespread and have diverted drainage patterns. The tectonically active area near the Garlock Fault Zone and the nearby El Paso Fault influenced development of drainage networks; base level is controlled by fault offset. Evidence of a late Tertiary drainage network is preserved in remnants of alluvial fans and paleodrainage deposits north of the El Paso Mountains, west of the Lava Mountains, and south and west of the Rand Mountains. Holocene fault activity for the Cantil Valley, Lockhart, Garlock, and Rand Mountain Faults is indicated by displaced stream channels, playa-filled depressions, scarps, and shutter ridges. Previously unmapped Holocene and Late Pleistocene fault strands identified near the Rand Mountains may represent a splay at the northwest termination of the Lockhart Fault. The Grass Valley Fault, northwest of Black Mountain, is a right-lateral, strike-slip fault that may be a splay of the Blackwater Fault. Holocene activity on the Grass Valley Fault is indicated by one displaced early Holocene stream terrace. Mapped faults in Fremont Valley are tentatively identified as surficial expressions of the buried Cantil Valley Fault.

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USGS2006

Surficial geologic map and geodatabase of the Cuddeback Lake 30' x 60' quadrangle, San Bernardino and Kern Counties, California

A USGS surficial geologic mapping project, focused on the arid Southwest USA, conducted mapping and process studies to investigate landscape development and tectonic evolution. This project included the Cuddeback Lake 1:100,000-scale quadrangle located in the western Mojave Desert north-northeast of Los Angeles, between the southern Sierra Nevada and San Bernardino Mountains, in Kern and San Bernardino Counties, California. Geomorphic features include high-relief mountains, small hills, volcanic domes, pediments, broad alluvial valleys, and dry lakes. The mapped area includes pre-Tertiary plutonic, metavolcanic, metasedimentary, and other metamorphic rocks; Tertiary sedimentary and volcanic rocks; and Quaternary sediments and basalts. Included in the area are the El Paso, Lockhart, Blackwater, and Muroc faults as well as the central segment of the Garlock fault zone. The tectonically active western Mojave Desert and the variety of surficial materials have resulted in distinctive geomorphic features and terrains. Mapping has shown that the tectonically active area near the Garlock fault zone and El Paso Fault influenced development of drainage networks; base level is controlled by fault offset. There is evidence of a late Tertiary drainage network preserved in remnants of alluvial fans and paleo-drainage deposits north of the El Paso Mountains, west of the Lava Mountains, and south and west of the Rand Mountains. Faults identified as being active in the Holocene based on displaced stream channels, scarps, and shutter ridges include the Cantil Valley, Lockhart, Garlock, and Rand Mountain faults. Previously unmapped Holocene and late Pleistocene fault strands identified near the Rand Mountains may represent a splay at the northwest termination of the Lockhart Fault. The informally named Grass Valley fault, NW of Black Mountain, is a right-lateral strike-slip fault that may be a splay of the Blackwater Fault. Holocene activity on the Grass Valley fault is indicated by one displaced early Holocene stream terrace. Mapped faults in Fremont Valley are tentatively identified as surficial expressions of the buried Cantil Valley fault.

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