Showing papers in "Geochimica et Cosmochimica Acta in 1997"

TL;DR: A suite of divalent metal (Ca, Cd, Ba) carbonates was synthesized over the temperature range 10-40°C by the classical method of slowly bubbling N 2 through a bicarbonate solution.

TL;DR: Estimates of the speciation of major, minor, and trace elements in hydrothermal and metamorphic fluids throughout most of the crust of the Earth are facilitated by correlations among experimentally determined standard partial molal thermodynamic properties.

TL;DR: In this article, the major and minor elements, including C and S, were analyzed for the Ramah Group sedimentary rocks in northeastern Labrador, Canada, to elucidate weathering processes on the Earth's surface about 1.9 Ga ago.

TL;DR: In this article, the thermodynamic properties of supercritical aqueous metal complexes using the revised HKF (Helgeson et al., 1981) equations of state and correlations between them and standard partial molal properties at 25 degrees C and 1 bar were derived.

TL;DR: In this paper, the authors quantified metal adsorption onto cell wall surfaces of Bacillus subtilis by applying equilibrium thermodynamics to the specific chemical reactions that occur at the water-bacteria interface.

TL;DR: In this article, the stability of colloidal, iron monosulfide suspensions with ionic strengths typical of marine and lacustrine waters was evaluated using DLVO theory and a term was included to account for the ferrimagnetic properties of greigite.

TL;DR: In this paper, a transport-controlled reaction of Fe(II) monosulfide by H2S in aqueous solutions between 25 and 125°C was investigated and the mean Arrhenius energy was 33.7 kJ mol−1.

TL;DR: The role of water in the formation of bitumen is investigated in this paper, where the authors evaluate the role of liquid water in bitumen formation and demonstrate that it is essential to the generation of an expelled saturate-enriched oil that is similar to natural crude oil.

TL;DR: The Toorongo Granodiorite, Australia, is similar to the average upper continental crust (AUCC) and the weathering characteristics of the profile provide insight into large-scale chemical weathering of the upper crust as mentioned in this paper.

TL;DR: In this article, carbon isotope data from freshwater and terrestrial snails, ahermatypic corals, and chemoautotrophic and methanotrophic pelecypods are also considered.

TL;DR: The Kamchatka arc (Russia) is divided into three segments by major sub-latitudinal fault zones (crustal discontinuities) as mentioned in this paper, where the southern (SS) and central (CS) segments are associated with the subduction of old Pacific lithosphere, whereas the northern, inactive segment (NS) was formed during westward subduction in young (< 15 Ma) Komandorsky Basin oceanic crust.

TL;DR: In this article, the contribution of plants to the biogeochemical cycle of Si and related weathering processes was studied in an equatorial rainforest ecosystem (Congo) where the biologic turnover of Si is high (58 to 76 kg/ha/y).

TL;DR: The fluxes of individual carbohydrates, amino acids, lipids and pigments have been determined in net-plankton, particulate matter and sediments from three sites (9°N, 5°N and 0°N) in the central equatorial Pacific to evaluate sources and reactivities of organic compounds as mentioned in this paper.

TL;DR: In this paper, surface sediments from Little Bahama Bank (LBB), intersecting the subtropical thermocline, were used to assess the influence of temperature on the incorporation of Mg, Sr, F, and Cd into shells of benthic foraminifera.

TL;DR: The model indicates that mixing environments are favorable for oxidation of H2S, CH4, Fe2+ and Mn2+ only below approximately 38 degrees C, with methanogenesis and reduction of sulfate or S degrees favored at higher temperatures, suggesting that environments dominated by mixing provide habitats for mesophilic (but not thermophilic) aerobes and thermophile anaerobes.

TL;DR: It is suggested that isotope fractionation accompanying elemental sulfur disproportionation contributes to the 34S depletion of sedimentary sulfides at the study sites.

TL;DR: In this article, high precision TIMS uranium, thorium, strontium, neodymium, and lead isotopes, along with complete major and trace element data, have been obtained on an extensive sample set comprising fifty-eight lavas along the arc as well as nineteen samples of the subducting sediments at DSDP site 204 just to the east of the Tonga-Kermadec trench.

TL;DR: In this paper, the authors assessed organic matter dynamics in coupled river/delta systems using mineral surface area as a conservative tracer for discharged riverine particulate organic matter (POM).

TL;DR: In this article, the authors provided field and laboratory evidence that N2 can also be produced by the oxidation of NH3 and organic-N with MnO2 in air and showed that these two reactions are more favorable as a couple than the oxidization of organic matter by O2 alone.

TL;DR: In this article, transmission electron microscope analysis of the lunar soil grains from the fine size fraction of several lunar soils showed that most grains are surrounded by thin (60-200 nm thick) rims.

TL;DR: In this article, the adsorption of phosphate and sulfate on goethite was studied individually and in combination at solution concentrations of phosphate ranging from 10 −8 to 10 −4 M and of sulfate ranging from 0.5 to 1.3 M.

TL;DR: This article found evidence of a negative regression between 6 i3C carbonate-6 '3Cwate, (A13C) and temperature: A13C = -1.78 - 0.18 T"C However, this relationship was aliased to a degree by a positive correlation between Ai3C and somatic growth and otolith precipitation rates.

TL;DR: In this article, the fractionation of silicon isotopes by three species of marine diatoms, Skeletonema costatum, Thalassiosira weissflogii, and Thalassoia sp., grown in batch culture, is reported.

TL;DR: In this article, the authors show that organic productivity under the California Current upwelling system was highest during OIS-3 and the Holocene, and lowest during the last glacial interval (LGI, ca. 24-10 ka).

TL;DR: The bulk and isotopic exchanges of O2, N2, NO3, and NH4+ between sediments and the overlying water (benthic flux) were measured at three shallow locations in Puget Sound using a benthic tripod as mentioned in this paper.

TL;DR: In this article, the suspended loads of the main streams on the island of Reunion have been analyzed for their major and trace element contents in order to characterise both chemical and mechanical erosion products.

TL;DR: In this article, ion microprobe zircon geochronology for three samples from the late Archaean Lewisian gneiss complex at Gruinard Bay, northwestern Scotland, in an attempt to resolve the discrepancy between SmNd and Pb-Pb isochron ages for trondhjemite and hornblendite components.

TL;DR: In this article, a revised solubility function for the temperature range 0-300°C was proposed, which is based on a combination of new quartz measurements in pure water that approached equilibrium from under-saturation at 21, 50, 74, and 96°C.

TL;DR: In this article, the authors analyzed the strontium isotope ratios of aragonite and gypsum from the Lisan Formation in the Perazim Valley (near the SW shore of the Dead Sea).

TL;DR: In this article, isotopic data for pyrite within microlaminated muds from two localities in the deep basin show striking uniformity between sites and down core, with a mean δ34SCDT value of −37.2 ± 0.9