Showing papers in "Chemical Geology in 2011"

TL;DR: In this article, the authors used a Thermo ElementXR single-collector ICPMS to determine the ages of seven well known apatite occurrences (Durango, Emerald Lake, Kovdor, Mineville, Mud Tank, Otter Lake and Slyudyanka).

TL;DR: In this paper, a nanoscale Fe(II)-Mo(VI) sulfide mineral is proposed to explain the Rogoznica lake's vertical mixing in autumn, but quickly restratifies and becomes intensely sulfidic during the succeeding 11 months.

TL;DR: Fluid-related coupled dissolution-reprecipitation processes can modify the composition of monazite and other orthophosphate minerals at temperatures well below diffusional closure temperatures as mentioned in this paper.

TL;DR: In this article, the carbonation rate of San Carlos olivine in batch experiments at 90 °C and pCO2 of 20 and 25 MPa was measured. And the results suggest that the formation of amorphous silica layers plays an important role in controlling the rate of olivines dissolution by passivating the surface of Olivine, an effect which has yet to be quantified and incorporated into standard reactivetransport codes.

TL;DR: A review of biogeochemical processes that operate on diel, or 24-hour, time scales in streams and the changes in aqueous chemistry that are associated with these processes can be found in this paper.

TL;DR: In this article, the authors reported new data on the geochemical and mineralogical compositions of tonsteins from the Songzao Coalfield, Chongqing, southwestern China, and provided new insights into the origin and distribution of the minerals and elements present.

TL;DR: Raman spectroscopy can be used for the rapid identification of a wide variety of minerals ranging from common iron oxy(hydroxides), such as ferrihydrite, to rare minerals, such as adelite.

TL;DR: In this article, the effect of acid treatment methods on the reliability of organic carbon [C] and nitrogen [N], and carbon isotope (δ13C) values on a range of terrestrial and aquatic, modern and geological environmental materials was investigated.

TL;DR: In this article, stable isotope data for vertical profiles of dissolved molybdenum of the modern euxinic water columns of the Black Sea and two deeps of the Baltic Sea were presented.

TL;DR: In this article, the authors provide geochemical and numerical analyses from the organic-rich Ecca Group in the Karoo Basin, South Africa, which was affected by contact metamorphism from multiple sill intrusions in the Early Jurassic.

TL;DR: In this paper, the concentrations of Rh, Au and other highly siderophile elements (HSE: Re, Os, Ir, Ru, Pt, Rh, Pd and Au), and 187Os/188Os isotope ratios have been determined for samples from peridotite massifs and xenoliths in order to further constrain HSE abundances in the Earth's mantle and to place constraints on the distributions processes accounting for observed HSE variations between fertile and depleted mantle lithologies.

TL;DR: The Zhongba ophiolite is located in the western part of the Yarlung Zangbo Suture Zone (YZSZ) separating Eurasia to the north from the Indian plate to the south as discussed by the authors.

TL;DR: In this article, the authors investigated isotope fractionation during reduction of stable chromium (Cr) isotopes by Fe(II)aq in batch experiments and showed that the reduction of Cr(VI) isotope composition of solids and solution displays Rayleigh distillation with α = 0.9985.

TL;DR: In this article, a series of flux-grown synthetic zircon crystals doped with Hf and selected rare earth elements (REE) were produced for use as a potential reference material for Lu-Hf isotopic analysis of Zircon by in situ laser ablation multi-collector inductively-coupled plasma mass spectrometry (LA-MC-ICPMS).

TL;DR: In this article, the accuracy and precision of micro-analysis of sulfur (S), chlorine (Cl) and bromine (Br) in quartz-hosted fluid inclusions by laser ablation (LA) inductively coupled plasma mass spectrometry (ICP-MS) were tested.

TL;DR: In this paper, the authors used chemical, isotopic and microbiologic techniques to evaluate the extent to which the addition of pyrite to groundwater and sediments from a nitrate-contaminated aquifer could stimulate denitrification by indigenous bacteria.

TL;DR: In this paper, the authors compare the ΣREE and shale-normalized (PAAS) REESN values of modern brachiopods (biogenic low-Mg calcite: bLMC) represented by several species from high- to low latitudes, from shallow- to deep waters and from warm- and cold-water environments, define three distinct average "seawater’ trends.

TL;DR: In this article, a case is emerging for fluid-induced nucleation of monazite, and accompanying apatite REE depletion, to be included as a typical but subtle paragenetic feature within the iron oxide-apatite deposit model.

TL;DR: In this paper, a combination of an inorganic and an organic geochemical approach is used to better assess the variability and diversity of past fluid and gas expulsion at seeps, and the results suggest that redox conditions at cold seeps are variable.

TL;DR: In this paper, the authors identify a significant, and previously unknown stage of subduction-related magmatism along the southern part of the eastern Qiangtang block, north of the Shuanghu suture, central Tibet.

TL;DR: In this paper, an internal standard-independent calibration strategy for LA-ICP-MS analysis of fifty-four major and trace elements in carbonate was described, based on the normalization strategy of bulk components as 100%, the MRM-NoIS (calibrated against multiple silicate reference materials without using internal standard) was used to correct the matrixdependent absolute amount of materials ablated during each run.

TL;DR: In this article, a model of both the structure and evolution of the Campi Flegrei caldera (CFc) magmatic feeding system, geochronological, geochemical and Sr, Nd, Pb and B isotopic data of representative volcanic products of the past 15-ka have been combined with geophysical and melt inclusion literature data, structural setting and dynamics of the resurgent calderas.

TL;DR: In this paper, a geochemical investigation of the Andean and Foreland basins of the Amazon River at high spatial and time resolution was carried out within the framework of the HYBAM research program (Hydro-geodynamics of Amazon Basin).

TL;DR: In this article, weight-loss experiments on synthetic single crystals of CePO4 and YPO4 were carried out using hydrothermal piston-cylinder methods at 800°C and 1.GPa, in H2O and H 2O-NaCl fluids.

TL;DR: In this paper, the solubility of synthetic magnesite was investigated from 50 to 200°C in NaCl solutions and in some cases under constant CO2 partial pressure (4-30 bars) both by means of a hydrogen electrode concentration cell (HECC) and a traditional batch Ti-reactor.

TL;DR: In this paper, the formation of Mg-rich carbonate in culture experiments using different aerobic bacterial strains and aqueous Mg/Ca ratios (2 to 11.5) at Earth surface conditions was studied.

TL;DR: In this article, the effects of tidal inundation on the geochemical zonation and cycling of Fe across a tidally inundated coastal acid sulfate soils (CASS) toposequence, by investigating topology, in situ porewater geochemistry, solid-phase Fe fractions and Fe mineralogy was examined.

TL;DR: This paper showed that apatites in ultramafic xenoliths from Hawaii, Kamchatka, Nunivak Island, Lunar Crater volcanic field and the Navajo volcanic field have variable volatile (F, Cl, OH) compositions that correlate with their petrogenesis.

TL;DR: In this article, the authors examined various chemical procedures for the analysis of rare earth element (REE) in authigenic carbonates, and presented a robust method using dilute acetic acid solution that allows the extraction of REE from carbonate phases with reduced contamination from Fe-Mn oxides and detrital minerals.

TL;DR: In this article, anoxic and oxic wetland soil incubation experiments, combined with analyses of soil solutions sampled from a natural wetland during a reduction event, are used to test the possibility that rare earth elements (REE) could be used as a tool to identify the soil phases contributing to trace metal solubilization.