Collaborative Studies (USC and UM): Fractionation of Ge and Si during Diagenesis, and its Implications for Regulating the Oceanic Ge/Si Ratio

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

To understand how the earth's climate might change in response to anthropogenic influence, such as the burning of fossil fuel, it is necessary to understand the natural variability of climate over glacial/interglacial times. One method of studying this variability is through investigation of the deep-sea sedimentary record, which contains chemical, fossil and mineralogic evidence of past climatic conditions. A potentially important signal in the sediments is the ratio of Ge to Si in opal, which varies in response to changing ocean conditions. To derive the maximum use of this tool, its chemical behavior in the sea floor must be fully understood. Therefore, this work will study the fractionation of Ge and Si in ocean sediments by laboratory experiments that would create a controlled diagenetic setting to determine the incorporation of Ge and Si into iron oxyhydroxices and sulfides. Additionally, existing pore water samples will be analyzed to investigate the behavior of Ge in different ocean settings. Field Studies in the California borderland will be carried out to collect additional pore waters and to deploy in-situ benthic chambers to measure the fractionation Ge and Si in different environments.