Showing papers in "Geochimica et Cosmochimica Acta in 2006"

TL;DR: Berner et al. as discussed by the authors presented a model for the combined long-term cycles of carbon and sulfur which combines all the factors modifying weathering and degassing of the GEOCARB III model.

TL;DR: In this article, the isotopic abundances of atmospheric Ar were determined using a dynamically operated isotope ratio mass spectrometer with minor modifications and special gas handling techniques to avoid fractionation.

TL;DR: In this paper, the authors proposed a carbonate-water paleothermometer, which is a thermodynamic-based approach to carbonate paleometric analysis. But it is not suitable for interpolation and even modest extrapolation, and it is rigorously independent of the d 18 O of water and d 13 C of DIC from which carbonate grew.

TL;DR: Refractory carboxyl-rich alicyclic molecules (CRAM) are characterized in marine dissolved organic matter (DOM) using nuclear magnetic resonance spectroscopy and ultra-high resolution mass spectrometry as discussed by the authors.

TL;DR: In this paper, the authors proposed a model for the near-coeval formation of the Archaean continental crust (dominantly tonalite-trondhjemite-granodiorite: TTG), which can be explained by melting the base of basaltic plateaux formed above mantle upwellings (plumes), leaving behind restites containing pyroxene, garnet, and rutile.

TL;DR: In this paper, a large red pegmatite sample from E. African pegmatites was used as a standard for U-Pb dating by laser ablation ICPMS.

TL;DR: In this paper, the authors show that high siliciclastic accumulation rates can swamp the enrichment mechanism, resulting in only intermediate DOP values for euxinic sediments and FeT/Al ratios that mimic the oxic shelf.

TL;DR: In this article, the authors used the HSE composition of fertile lherzolites to constrain the origin of the highly siderophile element (HSE) excess in Earth's mantle.

TL;DR: In this paper, the authors compare 490 published proxy records of CO2 spanning the Ordovician to Neogene with records of global cool events to evaluate the strength of CO 2-temperature coupling over the Phanerozoic (last 542my).

TL;DR: In this article, a thermodynamic model is presented to calculate methane solubility, liquid phase density and gas phase composition of the H2O-CH4 and H 2O−CH4-NaCl systems from 273 to 523 K (possibly up to 573 K), from 1 to 2000 K and from 0 to 6 kg−1 of NaCl with experimental accuracy.

TL;DR: Recrystallization of the more reactive iron oxides into more crystalline phases, induced by the appearance of Fe2+ in anoxic aquifers, may be an important trapping mechanism for arsenic.

TL;DR: In this paper, the U-Pb systematics of zircon and xenotime on the single-to sub-grain scale by high-precision ID-TIMS geochronology on 11 rock samples ranging from 0.1 to 3.3 Ga.

TL;DR: In this article, the authors used density functional perturbation theory (DFPT) with norm-conserving planewave pseudopotentials to determine the vibrational frequencies of isotopically substituted crystals.

TL;DR: In this paper, the apatite/melt trace element partition coefficients for a large number of trace elements (Cs, Rb, Ba, La, Ce, Pr, Sm, Gd, Lu, Y, Sr, Zr, Hf, Nb, Ta, U, Pb, and Th) were presented.

TL;DR: In this paper, the results from precipitation experiments carried out to investigate the partitioning of the alkaline earth cations Mg2+, Ca2+, Sr2+, and Ba2+ between abiogenic aragonite and seawater as a function of temperature were presented.

TL;DR: In this article, solid-phase Mo and U concentrations in marine sediments from the California, Mexico, Peru, and Chile margins were measured to ascertain the behavior of authigenic metal accumulation during early diagenesis in continental margin settings.

TL;DR: In this paper, the solubility data for amorphous ferric arsenate and scorodite have been reevaluated using the geochemical code PHREEQC with a modified thermodynamic database for the arsenic species.

TL;DR: In this paper, the authors measured hydrogen isotope compositions (δD) of high-molecular-weight n-alkanes (C27−C33) from grasses grown in greenhouses and collected from the US Great Plains.

TL;DR: Schwertmannite is a ubiquitous mineral formed from acid rock drainage (ARD), and plays a major role in controlling the water chemistry of many acid streams as mentioned in this paper, but it is not known how it is formed.

TL;DR: In this paper, an Inceptisol A-horizon from Hawaii was subjected to a series of reduction-oxidation cycles (14 d cycle length over a 56 d dura- tion)across the ''soil-Fe'' (Fe(OH)3.74) equilibrium in triplicate redox-stat reactors.

TL;DR: In this article, the authors used Synchrotron-based X-ray radiation microfluorescence (μ-SXRF) and micro-focused and powder extended Xray absorption fine structure (EXAFS) spectroscopy measurements, combined with desorption experiments and thermodynamic calculations, were used to evaluate the solubility of metal contaminants (Zn, Cu, Pb) and determine the nature and fractional amount of Zn species in a near neutral pH (6.5-7.0) truck-farming soil contaminated by sewage irrigation for

TL;DR: In this article, high-precision analyses of Δ33S and Δ36S values, defined as deviations of 33S and 36S from ideal mass-dependent relationships, for international reference materials and sedimentary sulfides of Phanerozoic age were performed using a fluorination technique with a dual-inlet isotope ratio mass spectrometer.

TL;DR: In this article, the authors investigate the responses of Mg-calcites to rising p CO 2 and ocean acidification by means of a simple numerical model based on the experimental range of biogenic Mgcalcite solubilities as a function of mg content in order to bracket the behavior of the most abundant Mg calcite phases in the natural environment.

TL;DR: In this paper, a view into both the Paleozoic and modern SCLM underlying the North China Craton (NCC) underlying the NCC was examined, and mantle xenoliths and xenocrystic chromites were extracted from three Pale-ozoic kimberlites (Tieling, Fuxian and Mengyin), and mantle Xenomorphs from one Cenozoic basaltic center (Kuandian).

TL;DR: In this paper, the maturity of the organic matter in matrix, determined by Raman spectroscopy, has been used as a powerful metamorphic tracer, independent of the mineralogical context and extent of aqueous alteration.

TL;DR: In this article, the Sb speciation in soil samples from Swiss shooting ranges was determined using Sb K-edge X-ray absorption spectroscopy (XAS) and advanced statistical data analysis methods (iterative transformation factor analysis, ITFA).

TL;DR: Charette et al. as discussed by the authors used pore water data from the Waquoit Bay coastal aquifer/subterranean estuary, along with Bay surface water data, to establish a more detailed view into the estuarine chemistry and the chemical diagenesis of Fe, Mn, U, Ba and Sr in coastal aquifers.

TL;DR: In this paper, the authors used Triton mass spectrometer to detect anomalous 142 Nd/ 144 Nd ratios of early Archean rocks. But their results were limited to the 3.6 to 3.8 Ga West Greenland craton.

TL;DR: In this article, the effect of Ca 2+ on U(VI) adsorption was investigated in NaNO3 solutions equilibrated with either ambient air (430 ppm CO2 )o r 2% CO 2 in the presence of 0, 1.8, or 8.9 mM Ca 2 +.

TL;DR: In this paper, large seasonal variations in the dissolved load of the headwater tributaries of the Marsyandi river (Nepal Himalaya) for major cations and 87Sr/86Sr ratios are interpreted to result from a greater dissolution of carbonate relative to silicate at high runoff.