Theses and Dissertations from UMD

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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

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Author: search.filters.author.Brody, KristinaSubject: search.filters.subject.biomarkers

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    Isotope and Organic Geochemistry of a Unique Proterozoic, Postglacial Succession: The Lapa Formation, Vazante Group, Brazil
    (2007-05-09) Brody, Kristina; Kaufman, Alan J; Geology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    This study is the second to investigate biological characteristics associated with Proterozoic glaciation via molecular fossils from organic matter preserved in shale. In the Vazante Group, Minas Gerais, Brazil, the Serra da Lapa Formation unconformably overlies a formation recently dated to ca. 1.13 Ga. Lithologic and isotopic data suggest the Lapa represents deposition immediately after either an early Neoproterozoic "snowball Earth" ice age or a possible regional, but still low-latitude, late Mesoproterozoic ice age. The relative abundances of biomarkers and other organic molecules show variations that match lithologic and isotopic changes observed in 40 meters of exploration drill core studied. Inconsistencies among biomarker abundances as well as differences between the organic matter of the Lapa Formation and that of the underlying formation hint at heterogeneity among and within formations. A more complete picture of the Vazante Group is warranted before characteristics of preserved organic matter can be interpreted in the context of depositional environments or postdepositional processes.