Geologic Map Database of the Oakland Metropolitan Area

A 1:24,000 scale digital map database depicts the distribution of bedrock and surficial deposits across Alameda, Contra Costa, and San Francisco Counties. Compiled by the U.S. Geological Survey from published, unpublished, and new mapping data, it provides information on geologic structure, stratigraphy, and regional history. The data was digitized from original manuscripts at scales of 1:62,500 and 1:24,000.

Use Cases

• Analyze map_unit lithology and age to model regional seismic velocity variations for ground motion prediction.
• Assess landslide potential by correlating surficial_deposit types with slope stability models.
• Study earthquake_fault locations and structures to understand regional tectonic framework and seismic hazard.
• Evaluate mineral_hazard distribution using geologic material properties from the compiled database.

Strengths

• Regional coverage at a detailed 1:24,000 scale for three counties.
• Compiled from multiple data sources including new mapping, published, and unpublished work.

Limitations

• Spatial resolution is limited to 1:24,000 scale, insufficient for site-specific development analysis.
• The database cannot be used to identify or delineate individual landslides.
• Does not replace official fault-rupture hazard zones designated by the California State Geologist.

Provenance

Source

U.S. Geological Survey (implied by stratigraphic nomenclature).

Collection Method

Digitized from stable originals and author manuscripts, scanned, vectorized, and edited in ARC/INFO GIS.

Time Range

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Freshness

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Geography

Oakland metropolitan area, Alameda, Contra Costa, and San Francisco Counties, California.