Aeromagnetic Survey At Clear Lake Area (Skokan, 1993)

GEOTHERMAL ENERGY

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Exploration Activity: Aeromagnetic Survey At Clear Lake Area (Skokan, 1993)

Exploration Activity Details
Location	Clear Lake Area
Exploration Technique	Aeromagnetic Survey
Activity Date
Usefulness	not indicated
DOE-funding	Unknown

Notes

USGS aeromagnetic data (Rapolla and Keller, 1984) were acquired at an elevation of 4500 feet and flown with one-mile spacings. These data were dominated by patterns of highs that coincide with serpentinite outcrops. Serpentinite is one component of the complex Franciscan melange. Fracturing within the Franciscan provides the porosity needed for collection of hot water characteristic of the Geysers Field. The Clear Lake Volcanics overlie the Franciscan formation. These in turn, are overlain by the Great Valley Sequence. The susceptibilities of both the Clear Lake Volcanics and Great Valley sequence are very low compared to the Franciscan melange and therefore are unrecognizable magnetically.

References

• Catherine K. Skokan (1993) Overview Of Electromagnetic Methods Applied In Active Volcanic Areas Of Western United States