Western Earth Surface Processes
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.
Geologic mapping has shown that active faults are widespread and have influenced 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. 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 during 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, 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.
Download the Readme file for this report as a PDF file (ReadMe_of06_1276.pdf; 24 KB)
Download the Readme file for this report as an ASCII file (ReadMe_of06_1276.txt; 16 KB)
Download the Pamphlet for this report as a PDF file. This file is to accompany the map and includes geologic interpretation, figures, and a description of map units (of06_1276_pamphlet.pdf; 128 KB)
Download the metadata for this report as ASCII. This is a text file of FGDC compliant metadata for this report (of06_1276_1a.txt; 40 KB)
Download the metadata for this report as HTML. This is an HTML file of FGDC compliant metadata for this report (of06_1276_1a.htm; 80 KB)
The database package includes the geologic map database files:
of06_1276_2a.mxd (520 KB)
of06_1276_2b.mdb (323.6 MB)
We have included a style file (of06_1276_2c.style; 792 KB) with embedded color and line types. The style contains a set of color fills with associated attributes used to assign the fills and line types in ArcMap to polygon and line features (arcs) by matching the attribute terminology. In ArcMap, styles are applied to features using the "Match to symbols in a style" choice under the "Categories" menu in Symbology tab. Note: consult the metadata or the Database Specifics section of this Report for details of the format and content of the digital database.
Download the Map as a ~70" x 36" PDF file (of06_1276_3a.pdf; 31.2 MB).
For questions about the content of this report, contact Lee Amoroso .
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Western Earth Surface Processes
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