Abstract

Please note different time and venue: Latimer Room, 4pm

In recent years, new geochemical proxies and emerging technologies have been combined to explore novel paleoclimatic questions that were only dreamed about a decade ago. In this presentation I will discuss how the application of new technologies such as laser ablation ICP -MS (e.g. Mg/Ca, Ba/Ca), SIMS (e.g. d18O, d13C) and nanoSIMS can be used to address old and new paleoceanographic problems. I will present data from laboratory experiments with living planktonic foraminifera that have allowed us to calibrate these proxies and reduce the spatial resolution of geochemical analyses to the micron and sub-micron level. These data confirm many of the fundamental geochemical relationships used by researchers to reconstruct ocean temperatures and water geochemistry from the fossil record. When individual foraminifera from a fossil assemblage are analyzed using LA-ICP-MS (Mg/Ca, Ba/Ca) and coupled to d18O measurements from standard isotope ratios mass spectrometry (IRMS), we may be able to extract novel information from the fossil record that was not previously possible. I will present data collected at the interface of these two geochemical technologies that has allowed us to calculate the oxygen isotopic composition of Laurentide Ice Sheet meltwater during the last deglaciation.