Cold seeps in Monterey Bay, California: Geochemistry of pore waters and relationship to benthic foraminiferal calcite

► We describe the geochemistry of pore waters in the Clam Flats area of Monterey Bay. ► The geochemical data are compared with the δ13C chemistry of benthic foraminifera. ► Living foraminifera indicate little effects of pore water low δ13C (DIC) in the clam bed. ► This phenomenon and its implications are discussed in detail. ► Implications with regards to paleo-methane seepage are discussed.