• Digital geologic map and map database of parts of Marin, San Francisco, Alameda, Contra Costa, and Sonoma Counties, California

    Metadata Updated: March 22, 2021

    This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area.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 (mageo.txt, mageo.pdf, or mageo.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 1:62,500 or smaller.

    Access & Use Information

    License: No license information was provided.

    Downloads & Resources


    Metadata Date June 13, 2016
    Metadata Created Date March 22, 2021
    Metadata Updated Date March 22, 2021
    Reference Date(s) January 1, 1999 (publication)
    Frequency Of Update asNeeded

    Metadata Source

    Harvested from USGS-Harvest

    Graphic Preview

    Image of entire map

    Additional Metadata

    Resource Type Dataset
    Metadata Date June 13, 2016
    Metadata Created Date March 22, 2021
    Metadata Updated Date March 22, 2021
    Reference Date(s) January 1, 1999 (publication)
    Responsible Party USGS Western Geologic Mapping Team (Point of Contact)
    Contact Email
    Access Constraints Use Constraints: Uses of this digital geologic map should not violate the spatial resolution of the data. Although the digital form of the data removes the constraint imposed by the scale of a paper map, the detail and accuracy inherent in map scale are also present in the digital data. The fact that this database was edited for a scale of 1:62,500 means that higher resolution information is not present in the dataset. Plotting at scales larger than 1:62,500 will not yield greater real detail, although it may reveal fine-scale irregularities below the intended resolution of the database. Similarly, where this database is used in combination with other data of higher resolution, the resolution of the combined output will be limited by the lower resolution of these data., Access Constraints: None
    Bbox East Long -122.24855051
    Bbox North Lat 38.2626288
    Bbox South Lat 37.73826442
    Bbox West Long -122.9902372
    Coupled Resource
    Frequency Of Update asNeeded
    Graphic Preview Description Image of entire map
    Graphic Preview File http://pubs.usgs.gov/mf/2000/2337/images/mf2337h.jpg
    Graphic Preview Type JPEG
    Licence Mention of commercial products or organizations is descriptive and does not constitute an endorsement by the government of those products or organizations.
    Metadata Language eng; USA
    Metadata Type geospatial
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True

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