Index Catalog // ScholarsArchive@OSU

Creator:: McManus, James
Abstract:: The exchange of waters between the Pacific and the Southern Oceans occurs along the eastern boundary of the South Pacific. Because water masses of the Antarctic provide a connection among the world's ocean basins, these water masses maintain the ability to influence changes in ocean circulation and climate (Lynch-Stieglitz et...
Resource Type:: Article

Creator:: Scholz, Florian, McManus, James, and Sommer, Stefan
Abstract:: A meaningful application of Mo as a paleo-redox proxy requires an understanding of Mo cycling in modern reducing environments. Stagnant euxinic basins such as the Black Sea are generally regarded as model systems for understanding euxinic systems during early Earth history. However, drawing direct parallels between the Black Sea and...
Resource Type:: Article

Creator:: Wheat, C. Geoffrey, McManus, James, Mottl, Michael J., and Giambalvo, Emily
Abstract:: We present a new estimate for the crustal phosphorous sink that results from reactions among seawater, basalt, and sediment blanketing low temperature mid-ocean ridge flank hydrothermal systems. New estimates for global hydrothermal power output, sediment thickness, and the dissolved phosphate concentrations in basement formation fluids indicate that fluid flow through...
Resource Type:: Article

Creator:: Abbott, April N., Haley, Brian A., and McManus, James
Abstract:: Because ocean circulation impacts global heat transport, understanding the relationship between deep ocean circulation and climate is important for predicting the ocean's role in climate change. A common approach to reconstruct ocean circulation patterns employs the neodymium isotope compositions of authigenic phases recovered from marine sediments. In this approach, mild...
Resource Type:: Article

Creator:: Abbott, April N., Haley, Brian A., and McManus, James
Abstract:: The ability to reconstruct past ocean currents is essential for determining ocean circulation’s role in global heat transport and climate change. Our understanding of the relationship between circulation and climate in the past allows us to predict the impact of future climate-driven circulation changes. One proposed tracer of past ocean...
Resource Type:: Article

Creator:: Abbott, April N., Haley, Brian A., McManus, James, and Reimers, Clare E.
Abstract:: We determined pore fluid rare earth element (REE) concentrations in near-surface sediments retrieved from the continental margin off Oregon and California (USA). These sites represent shelf-to-slope settings, which lie above, within, and below the oxygen minimum zone of the Northeast Pacific. The sediments are characterized by varying degrees of net...
Resource Type:: Article

Creator:: McManus, James, Nägler, Thomas F., Siebert, Christopher, Wheat, C. Geoffrey, and Hammond, Douglas E.
Abstract:: Isotopic analyses of dissolved molybdenum are presented for sediment pore waters from a reducing sedimentary basin and for fluids from a low-temperature ridge flank hydrothermal system. δ⁹⁸/⁹⁵Mo in these fluids range from 0.8 to 3.5%₀ (relative to a laboratory standard), demonstrating that marine sedimentary reactions significantly fractionate Mo isotopes. Within...
Resource Type:: Article

Creator:: McManus, James, Collier, Robert W., and Dymond, Jack
Abstract:: Subsurface hydrothermal activity dominates the heat and salt budgets of the deep water column in Crater Lake, Oregon. From a time series of conductivity-temperature-depth data and data from a thermistor chain mooring, we estimate that the net hydrothermal heat flow is ~1 W m⁻² and the corresponding salt flux is...
Resource Type:: Article

Creator:: McManus, James, Berelson, William M., Hammond, Douglas E., and Klinkhammer, Gary P.
Abstract:: Benthic incubation chambers have been deployed in a variety of geochemical environments that provide a comprehensive geochemical framework from which to address issues related to Ba geochemistry and the use of Ba as a paleoproxy. First order budgets for barium show that in the equatorial Pacific, present rates of Ba...
Resource Type:: Article

Creator:: Wheat, C. Geoffrey and McManus, James
Abstract:: We present concentrations of germanium and silicon in sediment pore waters, basaltic formation fluids, and bulk sediment from three ridge flank hydrothermal systems (RFHS). Basaltic formation fluids from warm (>30°C) RFHS have much higher Ge concentrations and Ge:Si molar ratios than overlying sediment pore waters, requiring seawater-basalt reactions to dominate...
Resource Type:: Article

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