Strontium (Sr) isotopes in the marine sediment record have the potential to shed light on past changes in the ocean-climate system. Although records of radiogenic Sr isotopes have been established, the analytical capabilities needed to measure stable Sr isotopes were developed only recently. The proposed work will take advantage of these analytical advances to measure stable Sr isotopes recorded in marine barite. The relationship between marine barite and stable Sr in seawater will be calibrated and used to reconstruct stable Sr in the global ocean for the past 130 million years. These data will be combined with an existing radiogenic Sr record to better understand global changes in seawater chemistry and biogeochemical cycles, and to determine their relationship to perturbations in tectonics and climate.
This work will help establish the utility of a relatively new tool in the study of past ocean and climate conditions. Training and mentoring will be provided for a graduate student and several undergraduate students, who will have the opportunity to present their research at scientific conferences. The PI will develop new curricula and continue ongoing outreach efforts. The project will facilitate collaboration between researchers at UCSC, Kent State University, the U.S. Geological Survey, and GEOMAR (Germany).