METHANE PRODUCTION IN SANTA-BARBARA BASIN SEDIMENTS

In vitro incubation of Santa Barbara Basin sediments indicated that methane production occurs at all depths sampled, including those in which sulfate reduction occurs. Methane production in the sulfate zone decreases with depth. U‐14C‐lactate is readily metabolized in the sulfate‐reducing zone, with 14CO2 production being greater than 14CH4 production. However, if sulfate is added to incubated sediments that have become depleted in sulfate, the 14CH4 production increases dramatically at the expense of 14CO2 production. Contrary to what has been observed in other ecosystems, sulfate stimulated methane production, especially from lactate. Experiments using 2‐14C‐acetate or H14CO3‐ have indicated that bicarbonate is the principal source of methane and acetate is oxidized to CO2 in sediments from the methane‐producing zone. © 1979 Taylor & Francis Group, LLC.