Connotea
CiteULike
del.ico.us
BibSonomyAbstract
Tropical sea-surface temperature reconstruction for the early Paleogene using Mg/Ca ratios of planktonic foraminifera
Department of Earth Sciences/Godwin Laboratory, University of Cambridge, Cambridge, UK
Department of Ocean Sciences/Institute of Marine Sciences, University of California, Santa Cruz, California, USA
Department of Earth Sciences/Institute of Marine Sciences, University of California, Santa Cruz, California, USA
Department of Ocean Sciences, University of California, Santa Cruz, California, USA
Department of Geology and Geophysics, University of Wisconsin, Madison, Wisconsin, USA
Department of Earth Sciences, University of Cambridge, Cambridge, UK
To understand the climate dynamics of hypothesized past greenhouse intervals, it is essential to constrain tropical sea-surface temperatures (SST), yet existing proxy records give conflicting results. Here we present the first Mg/Ca-based study of pre-Quaternary SST and investigate early Paleogene (late Paleocene through late middle Eocene; 58.6–39.8 Ma) tropical temperatures, using planktonic foraminifera belonging to the genus Morozovella from Ocean Drilling Program Site 865 on Allison Guyot (western central equatorial Pacific Ocean). Calcification temperatures similar to or warmer than modern tropical SST are calculated using a range of assumptions regarding diagenesis, temperature calibration, and seawater Mg/Ca. Long-term warming is observed into the early Eocene (54.8–49.0 Ma), with peak SST between 51 and 48 Ma and rapid cooling of 4°C beginning at 48 Ma. These findings are inconsistent with the δ18O-based SST previously estimated for this site.
Received 8 June 2003; accepted 7 October 2003; published 26 December 2003.
Citation: (2003), Tropical sea-surface temperature reconstruction for the early Paleogene using Mg/Ca ratios of planktonic foraminifera, Paleoceanography, 18(4), 1101, doi:10.1029/2003PA000937.
Cited By