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Aeromagnetic survey map of the central California Coast Ranges

April 29, 2009

This aeromagnetic survey was flown as part of a Cooperative Research and Development Agreement (CRADA) with the Pacific Gas and Electric Company and is intended to promote further understanding of the geology and structure in the central California Coast Ranges by serving as a basis for geophysical interpretations and by supporting geological mapping, mineral and water resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on aeromagnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals can commonly mark lithologic or structural boundaries. Bodies of serpentinite and other mafic and ultramafic rocks tend to produce the most intense magnetic anomalies, but such generalizations must be applied with caution because rocks with more felsic compositions, such as the porphyritic granodiorite-granite of the La Panza Range, and even some sedimentary units, also can cause measurable magnetic anomalies.

Citation Information

Publication Year 2009
Title Aeromagnetic survey map of the central California Coast Ranges
DOI 10.3133/ofr20091044
Authors V. E. Langenheim, R. C. Jachens, K. Moussaoui
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Open-File Report
Series Number 2009-1044
Index ID ofr20091044
Record Source USGS Publications Warehouse
USGS Organization Geophysics Unit of Menlo Park, CA (GUMP)