Geologic map of the Cape Mendocino, Eureka, Garberville, & southwestern part of the Hayfork 30 X 60 Quadrangles and Adjacent Offshore Area, Northern California

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (ceghmf.ps, ceghmf.pdf, ceghmf.txt), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey.

The scale of the source maps limits the spatial resolution (scale) of the database to 1:100,000 or smaller. This is the pre-release version of the report. The accompanying text file mf2336.rev contains version numbers for each part of the data set.

This report consists of a set of geologic map database files (Arc/ Info coverages) and supporting text and plotfiles. In addition, the report includes two sets of plotfiles (PostScript and PDF format) that will generate map sheets and pamphlets similar to a traditional USGS Miscellaneous Field Studies Report. These files are described in the explanatory pamphlets (ceghdesc and ceghdb).

The base map layer used in the preparation of the geologic map plotfiles was downloaded from the web (www.gisdatadepot.com) as Digital Raster Graphic files of scale-stable versions of the USGS 1:100,000 topographic maps and coverted to TIFF images which were then converted to GRIDs. These grids contain no database information other than position, and are included for reference only. The base maps used were the Cape Mendocino (1989 edition), Eureka (1987 edition), Garberville (1979 edition), Hayfork (1978 edition) 1:100,000 topographic maps, which all have a 50-meter contour interval.

The bathymetry maps were converted from the Coast and Geodetic Survey hydrographic chart 1308 N-12, 1969.