Geologic map and map database of the Spreckels 7.5-minute quadrangle, Monterey County, California

This database and accompanying plot files depict the distribution of geologic
materials and structures at a scale of 1:24,000. The report is intended to
provide geologic information for the regional study of materials properties,
earthquake shaking, landslide potential, mineral hazards, seismic velocity, and
earthquake faults. In addition, the report contains new information and
interpretations about the regional geologic history and framework. However,
the regional scale of this report does not provide sufficient detail for site
development purposes. In addition, this map does not take the place of
fault-rupture hazard zones designated by the California State Geologist (Hart
and Bryant, 1997). Similarly, the database cannot be used to accurately
identify or delineate landslides in the region.

This digital map database, compiled from previously published and unpublished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 (skmf.txt, skmf.pdf, or skmf.ps), 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 1:24,000 or smaller.

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 below:

>ARC/INFO Resultant Description of Coverage
>export file Coverage
>----------- ----------- --------------------------------
>sk-geol.e00 sk-geol/ Polygon and line coverage showing
> faults, depositional contacts, and
> rock units in the map area.
>
>sk-strc.e00 sk-strc/ Point and line coverage showing
> strike and dip information and fold axes.
>
>sk-lnds.e00 sk-lnds/ Point and line coverage showing arrows
> indicating landslide directions as well
> as the locations of wells and springs
> not included in the topographic base map.

ASCII text files, including explanatory text, ARC/INFO key files, PostScript
and PDF plot files, and a ARC Macro Language file for conversion of ARC export
files into ARC coverages:

>skmf.ps A PostScript plot file of the pamphlet
> containing detailed unit descriptions
> and geological information, a description
> of the digital files associated with the
> publication, plus references cited.
>
>skmf.pdf A PDF version of mamf.ps.
>
>skmf.txt A text-only file containing an unformatted
> version of skmf.ps.
>
>import.aml ASCII text file in ARC Macro Language to
> convert ARC export files to ARC coverages
> in ARC/INFO.
>
>skmap.ps A PostScript plottable file containing
> an image of the geologic map and base
> maps at a scale of 1:24,000, along with
> a simple map key.
>
>skmap.pdf A PDF file containing an image of the
> geologic map and base maps at a scale
> of 1:24,000, along with a simple map key.

Base maps

Base Map layers used in the preparation of the geologic map plotfiles were
derived from published digital maps (Aitken, 1997) obtained from the U.S.
Geological Survey Geologic Division Website for the Western Region
(http://wrgis.wr.usgs.gov). Please see the website for more detailed
information about the original databases. Because the base map digital files
are already available at the website mentioned above, they are not included in
the digital database package.