Geologic map of the Cape Mendocino area showing the location of the San Andreas Fault zone, the Mendocino Fracture zone, and the Pacific, Gorda, and North American plates.
These geologic maps and accompanying structure sections depict the geology and structure of much of northwestern California and the adjacent continental margin. The map area includes the Mendocino triple junction, which is the juncture of the North American continental plate with two plates of the Pacific ocean basin. The map area also encompasses major geographic and geologic provinces of northwestern California. The maps incorporate much previously unpublished geologic mapping done between 1980 and 1995, as well as published mapping done between about 1950 and 1978. To construct structure sections to mid-crustal depths, we integrate the surface geology with interpretations of crustal structure based on seismicity, gravity and aeromagnetic data, offshore structure, and seismic reflection and refraction data.
In addition to describing major geologic and structural features of northwestern California, the geologic maps have the potential to address a number of societally relevant issues, including hazards from earthquakes, landslides, and floods and problems related to timber harvest, wildlife habitat, and changing land use. All of these topics will continue to be of interest in the region, as changing land uses and population density interact with natural conditions. In these interactions, it is critical that the policies and practices affecting man and the environment integrate an adequate understanding of the geology.
Index map showing 7.5-minute quadrangles (diagonal names) within 30 x 60 minute quadrangles of map area.
Files available for download:
As a package
mf2336ps.zip PostScript files of the map sheets and pamphlet (as a .zip compressed file) (62.2 MB).
mf2336pdf.zip PDF plotfiles of map sheets and pamphlet (as a .zip compressed file) (32.4 MB).
As Individual Files
euhamap.pdf PDF file of map sheet 1 containing image of the geologic map and base map of the Eureka and southwestern part of the Hayfork quadrangles and adjacent offshore area (3.7 MB).
cmmap.pdf PDF file of map sheet 2 containing image of the geologic map and base maps of the Cape Mendocino quadrangle and adjacent offshore area (3.3 MB).
gamap.pdf PDF file of map sheet 3 containing image of the geologic map and base maps of the Garberville quadrangle and adjacent offshore area (8.1 MB).
ceghmap.pdf PDF file of map sheet 4 containing image of the geologic map and base maps of the Cape Mendocino, Eureka, Garberville, and southwestern part of the Hayfork quadrangles, and adjacent offshore areas, northern California (12.5 MB).
ceghexpl.pdf PDF file containing image of map keys, index maps, and unit descriptions for the Cape Mendocino, Eureka, Garberville, and southwestern part of the Hayfork 30 x 60 minute quadrangles, and adjacent offshore areas, northern California (2.7 MB).
ceghexpl2.pdf PDF file of sheet 6 containing image of 2 cross sections, K-feldspar locality index map, and seismicity section for the Cape Mendocino, Eureka, Garberville, and southwestern part of the Hayfork 30 x 60 minute quadrangles, and adjacent offshore areas, northern California (1.5 MB).
ceghmf.pdf PDF file of the accompanying pamphlet to the geologic maps (256 kb).
Download the database
ceghmfdb.txt ASCII text file that describes the digital database (48 kb).
ceghmfdb.pdf PDF file describing the contents of the digital database (456 kb).
mf2336.met.txt ASCII text file, FGDC-compliant metadata (156 kb).
mf2336db.zip Arc Info Export (.e00) and supporting files (as a .zip compressed file) (4.2 MB).
Revision list (4 Kb)
For questions about the scientific content of this report, contact Bob McLaughlin
Download a free copy of Adobe Reader.
This report is available via print on demand.
| PDF help |
| Publications main page | Miscellaneous Field Studies Maps |
| Department of the Interior | U.S. Geological Survey |
| Geologic Division | Earth Surface Processes Team |
| Privacy Statement | Disclaimer | Accessibility |
URL of this page is:
Please send comments and suggestions, or report problems, to: Michael Diggles
Created: April 27, 2000 (cad)
Updated: May 8, 2008 (mfd)