Collaborative Research: Paleoceanography of Eocene Decapod-Rich Rocks in Antarctica and Southern South America

Kent State University, Kent OH

Investigators

Abstract

Feldmann: OPP 9909184 Bice: OPP 9909719 Abstract This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a paleoceanographic investigation of Eocene rocks from the Antarctic Peninsula region. In order to evaluate the question of whether intervals of relative warmth in polar latitudes were seasonal or year-round, to determine seasonal temperature estimates for near-shore marine habitats, and to refine global paleoceanographic models, fossil mollusks will be collected from Eocene rocks in Antarctica and southern South America that are known to contain decapod crustaceans (crabs and lobsters). The sites at which decapod-rich rocks occur are targeted because the decapods provide a unique, diverse database on biogeographic distribution throughout the high southern latitudes. Collection of mollusks intimately associated with the decapods will permit determination of oxygen isotopic compositions (del-18-O values) necessary to provide proxy seasonal temperature estimates at the time and in the precise habitat that the decapods lived. Concomitant with that work, a series of oceanic and atmospheric circulation models will be run in which boundary conditions of atmospheric carbon dioxide and mean heat transport in climate model simulations of water circulation will be adjusted, using the GENESIS v. 2.0 atmospheric and GFDL MOM v. 2.0 ocean models. The water temperature data derived from analysis of fossil material will be used to select the most reasonable atmospheric and oceanic circulation models and to evaluate the effects of various gateways to circulation in the Antarctic region. The work will provide detailed information on seasonal variation in water temperature in near-shore environments of the high southern latitudes and will result in refined paleoecological interpretations for the decapods that will be essential to make comparisons between related fossil and extant species. The study provides a unique opportunity for paleontologists and modelers to work together in developing efficient ways to utilize specified seasonal sea surface temperature data when models are constructed. This program is collaborative between Kent State University, the lead institution, and the Woods Hole Oceanographic Institution. Furthermore, the work is collaborative with scientists from the Instituto Antartico Argentino.