Delta 44/40 Ca, Mg/Ca and Sr/Ca record of Globigerinoides sacculifer and calculated temperatures and salinity changes of ODP Hole 165-999A, supplement to: Gussone, Nikolaus; Eisenhauer, Anton; Tiedemann, Ralf; Haug, Gerald H; Heuser, Alexander; Bock, Barbara; Nägler, Thomas F; Müller, A (2004): Reconstruction of Caribbean Sea surface temperature and salinity fluctuations in response to the Pliocene closure of the Central American gateway and radiative forcing, using d44/40Ca, d18O and Mg/Ca ratios. Earth and Planetary Science Letters, 227(3-4), 201-214


The delta18O values of planktonic foraminifera increased in the Caribbean by about 0.5‰ relative to the equatorial East Pacific values between 4.6 and 4.2 Ma as a consequence of the closure of the Central American Gateway (CAG). This increase in delta18O can be interpreted either as an increase in Caribbean sea surface (mixed layer) salinity (SSS) or as a decrease in sea surface temperatures (SST). This problem represents an ideal situation to apply the recently developed paleotemperature proxy delta44/40Ca together with Mg/Ca and d18O on the planktic foraminifer Globigerinoides sacculifer from ODP Site 999. Although differences in absolute temperature calibration of delta44/40Ca and Mg/Ca exist, the general pattern is similar indicating a SST decrease of about 2-3 8C between 4.4 and 4.3 Ma followed by an increase in the same order of magnitude between 4.3 and 4.0 Ma. Correcting the delta18O record for this temperature change and assuming that changes in global ice volume are negligible, the salinity-induced planktonic delta18O signal decreased by about 0.4‰ between 4.4 and 4.3 Ma and increased by about 0.9‰ between 4.3 and 4.0 Ma in the Caribbean. The observed temperature and salinity trends are interpreted to reflect the restricted exchange of surface water between the Caribbean and the Pacific in response to the shoaling of the Panamanian Seaway, possibly accompanied by a southward shift of the Intertropical Convergence Zone (ITCZ) between 4.4 and 4.3 Ma. Differences in Mg/Ca- and delta44/40Ca-derived temperatures can be reconciled by corrections for secular variations of the marine Mg/Ca[sw] and delta44/40Ca, a salinity effect on the Mg/Ca ratio and a constant temperature offset of ~2.5 °C between both SST proxy calibrations.

Related Identifier
Related Identifier<0207:ROPUOO>2.0.CO
Metadata Access
Creator Gussone, Nikolaus
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2004
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Language English
Resource Type Supplementary Dataset
Format text/tab-separated-values
Size 332 data points
Discipline Earth System Research
Spatial Coverage (-78.739 LON, 12.744 LAT); Caribbean Sea
Temporal Coverage Begin 1996-01-10T19:30:00Z
Temporal Coverage End 1996-01-14T23:15:00Z