Benthic foraminiferal assemblages in ODP Hole 167-1017E

DOI

A strong oxygen-minimum zone (OMZ) currently exists along the California margin because of a combination of high surface-water productivity and poor intermediate-water ventilation. However, the strength of this OMZ may have been sensitive to late Quaternary ocean-circulation and productivity changes along the margin. Although sediment-lamination strength has been used to trace ocean-oxygenation changes in the past, oxygen levels on the open margin are not sufficiently low for laminations to form. In these regions, benthic foraminifera are highly sensitive monitors of OMZ strength, and their fossil assemblages can be used to reconstruct past fluctuations. Benthic foraminiferal assemblages from Ocean Drilling Program Site 1017, off Point Conception, exhibit major and rapid faunal oscillations in response to late Quaternary millennial-scale climate change (Dansgaard-Oeschger cycles) on the open central California margin. These faunal oscillations can be correlated to and are apparently synchronous with those reported from Santa Barbara Basin. Together they represent major fluctuations in the strength of the OMZ which were intimately associated with global climate change-weakening, perhaps disappearing, during cool periods and strengthening during warm periods. These rapid, major OMZ strength fluctuations were apparently widespread on the Northeast Pacific margin and must have influenced the evolution of margin biota and altered biogeochemical cycles with potential feedbacks to global climate change.

Dominant benthic foraminiferal species within the assemblages are as followed:Dysoxic (O2 = 0.1-0.3 ml/l) - Bolivina argentea, Boliminella tenuata, Chilostomella ovoideaSuboxic I (O2 = 0.3-1.5 ml/l) - Bolivina spissa, Uvigerina peregrina curticostaSuboxic II (O2 = 0.3-1.5 ml/l) - Bulimina mexicana, Cassidulina crassipunctata, Nonionella globosa, Valvulinaria araucunaOxic (O2 > 1.5 ml/l) - Cibicides mckannai, Epistominella pacifica, Epistominella smithi

Supplement to: Cannariato, Kevin G; Kennett, James P (1999): Climatically related millennial-scale fluctuations in strength of California margin oxygen-minimum zone during the past 60 k.y. Geology, 27(11), 975-978

Identifier
DOI https://doi.org/10.1594/PANGAEA.712956
Related Identifier https://doi.org/10.1130/0091-7613(1999)027<0975:CRMSFI>2.3.CO
Related Identifier ftp://rock.geosociety.org/pub/reposit/1999/9984.pdf
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.712956
Provenance
Creator Cannariato, Kevin G; Kennett, James P
Publisher PANGAEA
Publication Year 1999
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 2127 data points
Discipline Earth System Research
Spatial Coverage (-121.107 LON, 34.535 LAT); North Pacific Ocean
Temporal Coverage Begin 1996-05-28T02:00:00Z
Temporal Coverage End 1996-05-28T06:30:00Z