Stable carbon and oxygen isotopes and Mg/Ca ratios of foraminifers from ODP Site 202-1241 sediments

DOI

A combination of stable isotope records and Mg/Ca temperature estimates of four different planktonic foraminiferal species from Ocean Drilling Program Site 1241 allows differentiation between temperature and salinity changes in the tropical east Pacific (TEP) upper water column during the Pliocene (~5.7-2.1 Ma). The deviation of d18O records and Mg/Ca temperature estimates from thermocline-dwelling planktonic foraminifers suggests that local changes in salinity exerted a much stronger control on Pliocene TEP upper ocean water mass signatures than previously assumed. The most pronounced Pliocene change in TEP upper ocean stratification was the shoaling of the thermocline from ~4.8 to 4.0 Ma that was possibly triggered by changes in the configuration of low-latitude ocean gateways. During this time interval, mixed-layer temperatures and salinities remained relatively constant in contrast to a pronounced temperature (~6°C) and salinity decrease at the bottom of the photic zone. This change led to a new state in the thermal structure of the TEP, as the thermocline remained relatively shallow until ~2.1 Ma.

The age model of ODP Site 202-1241 is based on orbital tuning (Tiedemann et al., 2007, doi:10.2973/odp.proc.sr.202.210.2007). G. sacculifer, G. limbata and G. tumida were picked from the 355-400 µm fraction. G. dutertrei were picked from the 250-355 µm fraction.

Supplement to: Steph, Silke; Tiedemann, Ralf; Groeneveld, Jeroen; Sturm, Arne; Nürnberg, Dirk (2006): Pliocene changes in tropical east Pacific upper ocean stratification: Response to tropical gateways? In: Tiedemann, R; Mix, AC; Richter, C; Ruddiman, WF (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 202, 1-51

Identifier
DOI https://doi.org/10.1594/PANGAEA.774272
Related Identifier IsSupplementTo https://doi.org/10.2973/odp.proc.sr.202.211.2006
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.774272
Provenance
Creator Steph, Silke; Tiedemann, Ralf ORCID logo; Groeneveld, Jeroen ORCID logo; Sturm, Arne; Nürnberg, Dirk
Publisher PANGAEA
Publication Year 2006
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 3 datasets
Discipline Earth System Research
Spatial Coverage (-86.445W, 5.843S, -86.445E, 5.843N); North Pacific Ocean
Temporal Coverage Begin 2002-05-20T00:00:00Z
Temporal Coverage End 2002-05-24T15:10:00Z