Jessica Garvin

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High-resolution chemostratigraphy reveals an episode of enrichment of the redox-sensitive transition metals molybdenum and rhenium in the late Archean Mount McRae Shale in Western Australia. Correlations with organic carbon indicate that these metals were derived from contemporaneous seawater. Rhenium/osmium geochronology demonstrates that the enrichment is(More)
High-resolution geochemical analyses of organic-rich shale and carbonate through the 2500 million-year-old Mount McRae Shale in the Hamersley Basin of northwestern Australia record changes in both the oxidation state of the surface ocean and the atmospheric composition. The Mount McRae record of sulfur isotopes captures the widespread and possibly permanent(More)
The nitrogen cycle provides essential nutrients to the biosphere, but its antiquity in modern form is unclear. In a drill core though homogeneous organic-rich shale in the 2.5-billion-year-old Mount McRae Shale, Australia, nitrogen isotope values vary from +1.0 to +7.5 per mil (per thousand) and back to +2.5 per thousand over approximately 30 meters. These(More)
The speech of 17 Parkinsonian patients was evaluated before and after the administration of L-DOPA therapy. A significant difference was demonstrated after treatment for voice quality, articulation, and pitch variation, but not for rate of speech. Amount of speech improvement correlated significantly with amount of physical improvement. Although age and(More)
14 ________________________________________________________________________ 15 The ca. 1.8 Ga Duck Creek Formation, Western Australia, preserves 1000 m of 16 carbonates and minor iron formation that accumulated along a late Paleoproterozoic 17 ocean margin. Two upward-deepening stratigraphic packages are preserved, each 18 characterized by peritidal(More)