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Coring the Hayward-Rodgers Creek fault zone in San Pablo Bay, California, to unravel the history of faulting beneath the bay

News from USGS Pacific Coastal and Marine Science Center

From October 17-21, 2016, USGS scientists collected 20 core samples of bayfloor sediment along the Hayward-Rodgers Creek fault zone in San Pablo Bay, a northern extension of San Francisco Bay, California. The longest core measures nearly 4 meters. Detailed radiocarbon dating of benthic forams (one-celled microorganisms) in the core samples will aid in unraveling the history of faulting in the bay and constraining the age of the most recent surface-rupturing earthquake along this part of the fault zone. Recent high-resolution acoustic imaging revealed a direct link between the Hayward and Rodgers Creek faults and provided a framework for targeted sampling of offset sediment layers, unconformities, and peculiar gas pockets.

A woman stands near muddy sediment cores standing upright in a cage, and she is on a boat wearing a hard hat and life jacket.
On research vessel Retriever, in October of 2016, USGS scientists led by Janet Watt collected core samples of bayfloor sediment along the Hayward-Rodgers Creek fault zone in San Pablo Bay, California, to investigate the history of faulting beneath the bay.
B-roll: Sampling and Coring in San Pablo Bay

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