Showing papers in "Chemical Geology in 2012"

TL;DR: In this paper, the authors proposed Kernel Density Estimation (KDE), a more robust alternative to the Probability Density Plot (PDP), which also involves summing a set of Gaussian distributions, but does not explicitly take into account the analytical uncertainties.

TL;DR: In this article, the authors present a discussion of the Mo geochemistry of non-euxinic sediments, where hydrogen sulfide is sometimes present yet always restricted to pore waters.

TL;DR: In this paper, a review of the geochemical properties of UHP terranes is presented, focusing on the following issues in continental subduction zones: the time and duration of uHP metamorphism, the origin and action of metamorphic fluid/melt inside UHP slices, the element and isotope mobilities under HP to UHP conditions during continental collision, the origins of premetamorphic protoliths and its bearing on continental collision types, and the crustal detachment and crust mantle interaction in subduction channels.

TL;DR: In this paper, the authors examined U-Mo covariation in organic-rich sediments deposited mostly in the western Tethyan region during oceanic anoxic events (OAEs) of Early Jurassic to Late Cretaceous age.

TL;DR: For example, trace-metal/TOC ratios can provide insight into the degree of watermass restriction and estimates of deepwater renewal times in restricted anoxic marine systems.

TL;DR: In this article, the authors show that a large amount of trace element and isotope data in ocean island basalts (OIB) can be used to trace the geologic reservoirs that exchange mass with the mantle and to identify the geological processes that introduce enriched material into the Earth's mantle.

TL;DR: In this article, a new analytical protocol is introduced for rapid measurement of rare-earth elements (REE), Sc and Y in meteoritic and geological materials by multi-collection inductively coupled plasma mass spectrometry (MC-ICP-MS).

TL;DR: In this paper, the authors reported new zircon LA-ICP-MS U-Pb age and Hf-isotope, whole-rock major and trace element, and Sr-Nd isotope data from Cambrian metavolcanic rocks in the central Lhasa subterrane.

TL;DR: In this article, the authors used high resolution and energy filtered transmission electron microscopy (HRTEM, EFTEM) to study mineral-fluid interfaces using TEM foils cut directly across the reaction boundaries, which allowed measurements to be made directly in cross section at nanometer to sub-nanometer resolution.

TL;DR: In this article, the results of monazite/melt partitioning experiments were conducted in the piston-cylinder apparatus at 10-50kbar and 750-1200°C, using a synthetic granite mix with approximately 10.5% H2O and doped with trace-elements in proportions corresponding to the composition of Monazite.

TL;DR: In this paper, a comparison of handheld energy-dispersive and wavelength-distpersive x-ray fluorescence (ED-XRF) results from pressed powder pellets of the Mississippian-age Barnett Shale of North-Central Texas, USA, is presented in order to evaluate the reliability of the reference calibration and the quantification of unknown samples using two different instrument platforms.

TL;DR: Zhang et al. as discussed by the authors integrated in situ U-Pb, Hf and O isotope analyses of detrital zircons from the Middle to Late Permian sediments in southeastern China, and use these data to decipher the sedimentary provenances, regional magmatic barcode and crustal evolution processes.

TL;DR: In this article, a protocol for precise and accurate LA-ICP-MS analysis of calcite and aragonite layers of a stalagmite and found large variations for Mg, Zn, Sr, and U in ostracod shells, indicating the potential for paleoclimate research.

TL;DR: In this paper, the authors used GIS-based models for estimating the concentration of radiogenic Sr isotopes in silicate and carbonate rocks, and applied these models to predict the contribution of different rock types to 87Sr/86Sr variations in water as a function of their weathering rates and strontium content.

TL;DR: In this article, the authors present data from two zircon populations with extremely high-uranium concentrations in an attempt to quantify effects related to the nature of the samples and instrumentally induced fractionation (instrument, analytical setup, and/or matrix effect).

TL;DR: In this article, several Late Yanshanian syenitic and gabbroic rocks from the coastal area of southeastern China have been studied to determine zircon U-Pb ages and Hf isotopic compositions.

TL;DR: In this article, the authors show that the Shuangliao basalts have the highest Fe 2 O 3 contents (13.4-14.6 W ) and lowest Fe 1 O 3 ratios (18.13-18.34 W ) expected for a HIMU basalt, in contrast to the majority of Chinese Cenozoic basalts, which plot above the NHRL.

TL;DR: A highly integrated geochemical program was conducted at the Cranfield CO2enhanced oil recovery (EOR) and sequestration site, Mississippi, U.S.A. as mentioned in this paper.

TL;DR: In this article, the effect of variable substructures on the sorption sites of hexagonal birnessites with various Mn average oxidation states (AOS) was investigated, and the results showed that a decrease in Mn AOS of a given birnessite decreased considerably the capacity for heavy metals, despite the fact that the specific surface area increased almost linearly.

TL;DR: In this paper, low-temperature alteration of monazite is documented in three centimeter-sized monazites from Norway (Arendal), Madagascar (Ambato), and Sri Lanka.

TL;DR: In this paper, the authors explore the possibility of tracing recycled carbonate by using Mg isotopes and evaluate the effects of the western Pacific oceanic subduction on the upper mantle evolution of the North China craton.

TL;DR: In this paper, an elastic recoil detection analysis (ERDA) was used to measure the H contents of 18 synthetic Fo90 olivines that had been hydrated to varying degrees in high pressure hydrothermal experiments.

TL;DR: In this article, a combined study of zircon U-Pb ages, Lu-Hf isotope, mineral O isotopes, whole-rock elements and Sr-Nd isotopes was carried out for alkaline intrusive rocks (including gabbro, syenite and granite) in the Sulu orogen.

TL;DR: In this article, the authors report a remarkable variation range in trace element, iron speciation and molybdenum isotope signatures of black shales from the Early Cambrian Dingtai profile (Guizhou province) and three synsedimentary polymetallic Ni-Mo-(PGE-Au) sulfide ore deposits (Dazhuliushui and Maluhe and Sancha in Hunan province) on the Yangtze Platform, South China.

TL;DR: In this article, the authors studied the interactions between Fe(III) and aquatic organic matter from the Suwannee River at a range of pH values and Fe concentrations (6489-55,659 μg g− 1 dry weight, pH 3.0-6.8) by means of extended X-ray absorption fine structure (EXAFS) and infrared (IR) spectroscopy.

TL;DR: Li et al. as discussed by the authors presented high-resolution carbon and sulfur isotopic data respectively for organic carbon and pyrite, and iron speciation data from the deep-water Liuchapo and Niutitang Formations on the Yangtze block, South China.

TL;DR: In this paper, the authors present a method to reconstruct the dehydration flux associated with garnet-forming reactions during subduction by using a test case of a mafic blueschist from the island of Sifnos, Greece, in the Attic Cycladic Blueschist Belt.

TL;DR: In this paper, a reaction path model was developed to simulate in situ CO2 mineralization through carbonation of fresh peridotite, with its composition based on that of mantle peridotsite in the Samail Ophiolite and including dissolution kinetics for primary minerals.

TL;DR: In this article, the authors report on improvements to the sulfur extraction method out of silicate glasses by the use of HF+CrCl2 solution for the precise determination of S multi-isotope compositions.