SGER:Geochronology of Ross Sea Carbonates: Collaborative participation with the Italian National Antarctic Research Program CARBONANT Cruise 2002

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

0202911 Hart This award, provided by the Office of Polar Programs, allows a US investigator to join a marine geological research cruise (the CARBONANT project) sponsored by the Italian National Antarctic Research Program and to begin a new collaborative research project with Italian scientists. The project is to study Quaternary to recent biogenic carbonate production and sedimentation in the Ross Sea. Sediment facies enriched in biogenic carbonate are known from several portions of the Ross Sea continental shelf and slope, however, the content and distribution of these facies are incompletely known. In addition, the accumulation rates for these facies have never been documented. Shipboard work will provide an initial assessment of carbonate preservation and faunal content. Marine biogenic carbonates (e.g. mollusc shells, foraminifera) are important vectors for paleoclimatic and geochronologic information. Collections made during this cruise are intended for use as baseline for Ross Sea biogenic carbonate stable isotope and geochronologic data. Following the shipboard work, samples will be analyzed in the Amino Acid Dating Laboratory at INSTAAR at the University of Colorado. This lab will perform amino acid analysis on carbonate shelly fossils isolated from sediment samples collected on the CARBONANT cruise. Amino acid analysis is a useful geochronologic tool that has received only limited use in previous Antarctic geologic studies. This analytical method can discern fossil ages between modern and 5 million years before present. Amino acid analysis is best applied to biogenic carbonate (e.g. mollusc shells). Paired geochronologic analyses will be performed on single shell specimens including AMS radiocarbon and amino acid analysis. The use of paired analyses will enable calibration of amino acid racemization rates in Ross Sea sediments and an initial assessment of Ross Sea bottom water temperatures. The data collected through this project will be interpreted jointly with Italian researchers.