Preliminary description and interpretation of cores and radiographs from Clear Lake, Lake County, California: Core 7

Open-File Report 75-144
By:  and 

Links

Abstract

Clear Lake, California is located in the California Coast Ranges about 120 km north of San Francisco and is the largest freshwater lake wholly within California. The lake basin is tectonically controlled (Anderson, 1936; Brice, 1953, Sims and Rymer, 1974) and the area seismically active (Coffman and von Hake, 1973).

Interest in this lake was stimulated by hypotheses developed from a study of sediments in Van Norman Reservoir after the 1971 San Fernando earthquake (Sims, 1973). During this study three zones of deformational structures were found in the 1 m-thick sequence of sediments exposed over about 2 km2 of the reservoir bottom. These zones were correlated with moderate earthquakes that shook the San Fernando area in 1930, 1952, and 1971. Results of this study, coupled with the experimental formation of deformational structures similar to those from Van Norman Reservoir, led to a search for similar structures in Pleistocene and Holocene lakes and lake sediments in other seismically active areas. Clear Lake, California was chosen specifically because of .:s location near the San Andreas fault and the San Francisco-Oakland urban complex, and the probability of obtaining an uninterrupted sediment record from the present into Pleistocene time. Eight 12 to 15 cm diameter continuous cores were taken from the lake sediments (fig. 1) as part of a study of earthquake induced structures in sediments and the tectonic framework of the Clear Lake basin. The eight cores range in length from 13.87 m to 133.09 m (Table 1).

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Preliminary description and interpretation of cores and radiographs from Clear Lake, Lake County, California: Core 7
Series title Open-File Report
Series number 75-144
DOI 10.3133/ofr75144
Year Published 1975
Language English
Publisher U.S. Geological Survey
Description 21 p.
Country United States
State California
County Lake County
Other Geospatial Clear Lake
Google Analytic Metrics Metrics page
Additional publication details