LAUSR

Abstract The Ixtoc-1 oil spill (1979–80) released 475 million liters of petroleum into the Southern Gulf of Mexico (sGoM) likely causing Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA) to occur. A multiproxy approach including short-lived radioisotopes (210Pbxs), benthic foraminifera stable isotopes (δ13CCaCO3), and volcanic sediment grains was used to investigate regional events (e.g. oil spills and volcanic eruptions) recorded in sedimentary records. Depleted δ13CCaCO3 from 1979 to 80 outside of natural variability most likely results from petrogenic carbon deposition 100–250 km west of Ixtoc-1, possibly associated with MOSSFA. An event, characterized by increased volcanic input, depleted δ13CCaCO3, and increased mass accumulation rates was consistent with the El Chichon eruption (1982) 80–100 km north of Ixtoc-1. Many factors confound the uniform distribution and preservation of these events in the sGoM. However, a multiproxy approach may aid to distinguish multiple events in the sGoM sedimentary record.