Data release of Geologic data for the Aeromagnetic Map of Northeastern California

This digital data release contains geospatial geologic data compiled for northeastern California, a region predominantly covered by Quaternary and Neogene volcanic rocks. Geologic map data were compiled for the purposes of interpreting data from two aeromagnetic surveys that were flown for the area; geologic compilation focused on the existence and location of faults and volcanic features - those geologic elements considered most likely to produce a magnetic anomaly. Geologic data, compiled from published sources, include the location and characteristics of geologic contacts and faults, mapped geologic polygons, boundaries of volcanic edifices, and the location of volcanic vents. The digital geologic database presented here is a companion dataset to two data releases of geophysical data from the aeromagnetic surveys. Both the geologic and geophysical data are intended to support the eventual interpretive USGS publication "Aeromagnetic Map of Northeastern California ". The geologic database includes spatial feature classes that collectively contain the geologic information that will be presented in the published map plate. The spatial data are accompanied by non-spatial tables that describe the sources of geologic information, a description of geologic map units, a glossary of terms, and a Data Dictionary that duplicates the Entity and Attribute information contained in the metadata file. Spatial data are also released as shapefiles.