11. Pliocene Paleoclimatology at ODP Site 1115, Solomon Sea (Southwestern Pacific Ocean), Based on Calcareous Nannofossils1

William G. Siesser2

ABSTRACT

The relative abundance of warm-water Discoaster brouweri vs. cool-water Coccolithus pelagicus provides a useful proxy for interpreting Pliocene surface water temperature trends at Ocean Drilling Program Site 1115 (Solomon Sea). Surface waters were mostly warm during the early Pliocene with a slightly cooler interval centered on 4.5 Ma. A more pronounced cool interval occurred at ~3.2 Ma. The early and mid-Pliocene cool periods may reflect Antarctic glacial growth. A mid-Pliocene warm interval occurred from ~3.1 to 2.8 Ma. Temperature began to decline beginning ~2.7 Ma, marking the onset of Northern Hemisphere glaciation. This long-term decline in surface water temperature is interrupted by a brief warming event at ~2.3 Ma.

1Siesser, W.G., 2001. Pliocene paleoclimatology at ODP Site 1115, Solomon Sea (southwestern Pacific Ocean), based on calcareous nannofossils. In Huchon, P., Taylor, B., and Klaus, A. (Eds.), Proc. ODP, Sci. Results, 180 [Online]. Available from World Wide Web:
<http:// www-odp.tamu.edu/publications/180_SR/154/154.htm>. [Cited YYYY-MM-DD]

2Department of Geology, Vanderbilt University, Box 46, Station B, Nashville TN 37235, USA. siesser@ctrvax.vanderbilt.edu

Initial receipt: 6 November 2000
Acceptance: 10 June 2001
Web publication: 13 September 2001
Ms 180SR-154

NEXT