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GIS data for the geologic map of the central Mayacmas Mountains and The Geysers steam field, Sonoma, Lake, and Mendocino counties, California

April 14, 2026

This file geodatabase contains a GeMS-compliant 1:24,000-scale digital geologic map of The Geysers geothermal field and surrounding region in the northern California Coast Ranges and the Mayacamas Mountains. The database includes geologic map unit polygons, contacts, faults, geologic linework, structural orientation data, overlays, and supporting tables such as DataSources, DescriptionOfMapUnits, GeoMaterialDict, and Glossary. This dataset is part of a digital GeMS-compliant geologic map database for The Geysers geothermal field and surrounding region, derived from the original printed geologic map by Robert J. McLaughlin (1978, USGS Open-File Report 78-389).

Publication Year 2026
Title GIS data for the geologic map of the central Mayacmas Mountains and The Geysers steam field, Sonoma, Lake, and Mendocino counties, California
DOI 10.5066/P13KBJ8H
Authors Alyssa (Contractor) K Hachmann, Benjamin L Melosh, Zenon C Valin, Robert J McLaughlin
Product Type Data Release
Record Source USGS Asset Identifier Service (AIS)
USGS Organization National Cooperative Geologic Mapping Program
Rights This work is marked with CC0 1.0 Universal
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