Showing papers in "Geochimica et Cosmochimica Acta in 1974"

TL;DR: The tracer diffusion coefficients of ions in deep-sea sediments, Dj,sed., can be related to Dj∗ by as mentioned in this paper, where θ is the tortuosity of the bulk sediment and a constant close to one.

TL;DR: In this paper, the exact determination of REE and Ba abundances in three carbonaceous (Orgueil Cl, Murchison C2 and Allende C3) and seven olivine-bronzite chondrites were carried out by mass spectrometric isotope dilution technique.

TL;DR: In this paper, the chemical and stable isotope compositions of unpolluted ground waters in carbonate terranes are a function of the pH, PCO2, 13C content of the ground water recharge, the 13C contents of the carbonate rock, and the manner in which the rock is dissolved or precipitated.

TL;DR: The mineralogy of Iherzolite inclusions in Victorian basanites indicates an upper mantle origin, but a range of temperatures from igneous to metamorphic (subsolidus) is indicated by the mineral compositions as discussed by the authors.

TL;DR: In this paper, a general model for mixing processes between river and ocean water is presented, in which established criteria for the identification of any non-conservative behavior of the dissolved constituents involved.

TL;DR: In this paper, the lowest 87Sr/86Sr observed for any suite of carbonates is taken as the best approximation to the value in well-mixed contemporary seawater.

TL;DR: The concentrations of rare-earth elements (REE) have been measured in 31 ferromanganese nodules from the Pacific and Indian Oceans and vary by almost a factor of 5.

TL;DR: In this article, the distribution of Au and Re between nickel-iron and basaltic melts was studied at 1400-1600°C, using radioactive tracers, and the results showed that gold abundances in lunar basalts are roughly consistent with the measured DAu, but those in terrestrial basalts were two orders of magnitude too high.

TL;DR: In a comprehensive study of the distribution of organic and inorganic constituents in natural waters, the chemical compositions of several rivers flowing through the Coastal Plain of southeast Georgia (the Satilla River, in particular) have been investigated as discussed by the authors.

TL;DR: In this paper, a logarithmic model for trace element partitioning was further developed for use in describing the behavior of the elements during solidification of the Skaergaard intrusion in order to optimize within limits of uncertainty of measured values, such as bulk composition, zone size, relative proportions of cumulus plus adcumulus minerals, zone mineralogy, and distribution coefficients.

TL;DR: In this article, experimental and predicted thermochemical constants are used to assess the formation and stability of lead phosphates in soil and sedimentary environments, and theoretical phase relationships together with several field observations are used as the basis for suggesting that the interaction of lead and phosphorus (to form pyromorphites and plumbogummite in particular) is an important buffer mechanism controlling the migration and fixation of lead in the environment.

TL;DR: In this paper, the authors used incremental heating for 11 terrestrial rocks and minerals whose geology indicates that they represent essentially undisturbed systems, including muscovite, biotite, hornblende, sanidine, plagioclase, dacite, diabase and basalt.

TL;DR: In this article, the Gibbs energies of formation of layer and fibrous silicates were estimated within the limits of uncertainty of the values obtained by current experimental techniques, based on the assumption that each silicate can be represented by oxide and hydroxide components possessing Gibbs energies within the silicate structures.

TL;DR: In this article, extreme pure samples of clinopyroxene phenocrysts from two volcanic rocks have been analyzed for K, Rb, Cs, Sr and Ba and partition coefficients are obtained which are in the range 0.001-0.004 for K. These results are lower than those in the literature by factors of 6-100 but are in good agreement with values determined experimentally at pressures of 15-30 kb by Shimizu (Geochim.

TL;DR: In this article, the authors found that the orange glass droplets from Apollo 11 and 17 sites and the green glasses from the Apollo 15 site may have formed in lava fountains of low-viscosity lunar basaltic magmas.

TL;DR: In this article, the negative logarithm of the dissociation constant of the CaHCO 3+ ion pair, p K ( CaCO 3 + ), is computed from conductance measurements.

TL;DR: In this article, high-molecular-weight constituents of the branched and cyclic hydrocarbon fraction of the Messel oil shale (Eocene) have been examined by high-resolution gas chromatography and combined GC/mass spectrometry.

TL;DR: The coarse-grained fraction of C2 chondrites is composed mostly of single crystals and aggregates of crystals of Mg-rich olivine and pyroxene as discussed by the authors.

TL;DR: The most abundant and most frequently found minerals are: sulfur, hematite, halite, sylvite, gypsum, ralstonite, anhydrite, thenardite and langbeinite.

TL;DR: In this article, the authors analyzed sediment cores of the western Baltic Sea for heavy metal and carbon isotope contents and determined the sedimentation rate was determined from radiocarbon dates to be 1.4 mm/yr.

TL;DR: In this paper, the authors determined the solubility of sulfur in volcanic rock melts (tholeiite basalt, hawaiite and rhyodacite from Hawaii) at various gas compositions and at 1250 and 1300°C and 1 atm total pressure.

TL;DR: In this paper, a natural, nonperthitic orthoclase has been studied isothermal heating experiments between 500° and 800°C under both vacuum and hydrothermal (2 kbar) conditions.

TL;DR: In this paper, the authors explain the lack of equilibrium between dissolved and reactive O2 and the presence of ionic Mn species on seafloor sediments by using surface adsorption and cation substitution within disordered birnessite-todorokite structure.

TL;DR: The volcanic rocks of Iceland are anomalous in their oxygen isotope content. as mentioned in this paper showed that the Icelandic basalts that resemble ridge basalts in δO18 also resemble them in major element chemistry.

TL;DR: The distribution coefficients of Eu and Sr for plagioclase-liquid and clinopyroxene-liquid pairs as a function of temperature and oxygen fugacity were experimentally investigated using an oceanic ridge basalt enriched with EU and Sr as the starting material.

TL;DR: The partition coefficients of K, Rb, Cs, Sr and Ba between clinopyroxene and liquid were experimentally determined in the system diopside-albite-anorthite-water at 15-30 kb and 1100-1200°C as discussed by the authors.

TL;DR: The isotopic composition of the elemental, sulfate, pyritic and organic sulfur in a wide range of Australian coals has been determined as discussed by the authors, and the S34 contents of the organic sulfate in coals containing more than 1 per cent total sulfur vary widely (dS34 + 2·9 to +24.4·) and contrast sharply with the narrow range of values found for the organic sulfur for coals of low total sulfur content.

TL;DR: In this article, a detailed study of the petrographic and chemical properties of carbonaceous chondrites was performed and it was shown that the four distinct chondrite subtypes may be related to one of two distinct chemical subdivisions.

TL;DR: The isotopic composition of groundwater sources of the Sinai Desert was surveyed in this article, characterized by a large spread in the oxygen-18 and deuterium abundances, compared to equivalent systems from less arid climates.