Steph, S et al. (2006): Stable carbon and oxygen isotopes and Mg/Ca ratios of foraminifers from ODP Site 202-1241 sediments. doi:10.1594/PANGAEA.774272, 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, doi:10.2973/odp.proc.sr.202.211.2006
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.
Minimum Age: 2116.000 ka BP * Maximum Age: 5766.000 ka BP
202-1241 * Latitude: 5.842833 * Longitude: -86.444683 * Date/Time: 2002-05-20T00:00:00 * Elevation: -2026.8 m * Recovery: 810.10 m * Penetration: 932.90 m * Location: North Pacific Ocean * Campaign: Leg202 * Basis: Joides Resolution * Device: Composite Core * Comment: 86 cores; 799 m cored; 133.9 m drilled; 101.4 % recovery
202-1241A * Latitude: 5.842830 * Longitude: -86.444500 * Date/Time Start: 2002-05-20T15:45:00 * Date/Time End: 2002-05-22T19:20:00 * Elevation: -2027.3 m * Recovery: 404.86 m * Penetration: 394.40 m * Location: North Pacific Ocean * Campaign: Leg202 * Basis: Joides Resolution * Device: Drilling * Comment: 43 cores; 394.4 m cored; 0 m drilled; 102.7 % recovery
202-1241B * Latitude: 5.842830 * Longitude: -86.444680 * Date/Time Start: 2002-05-22T19:20:00 * Date/Time End: 2002-05-24T15:10:00 * Elevation: -2025.8 m * Recovery: 302.23 m * Penetration: 395.00 m * Location: North Pacific Ocean * Campaign: Leg202 * Basis: Joides Resolution * Device: Drilling * Comment: 32 cores; 303.6 m cored; 91.4 m drilled; 99.5 % recovery
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.