Keil (OCE-9711792) ABSTRACT Keil OCE-9711792 Geochemists have long recognized the potential importance of mineral surfaces in protecting and preserving marine organic matter (OM) in aquatic sediments. This proposal seeks to further out understanding of OM preservation by evaluating in more detail the organic mineral to mineral surface area ratio (OM:SA) which has recently been shown by this PI and others to be useful for evaluating OM preservation in marine sediments. The proposed measurements are aimed at answering fundamental questions in marine geochemistry about the factors and processes that form and mold the OM:SA relationship. A wide range of approaches will be used to evaluate marine sediments, including: a combination of probing techniques (X-ray photoelectron spectroscopy (XPS), UV photooxidation, density fractionation); adsorbing extracted organic matter to know mineral phases; and, conducting microbial degradation experiments. The PI will conduct these experiments on samples collected from contrasting redox environments and OM:SA settings. The proposed studies build on successful experiments previously conducted by the PI and should lead to a significant advancement in our understanding of OM preservation in ocean sediments.
