Showing papers in "Chemical Geology in 2002"

TL;DR: In this article, the authors proposed a correction method that neither uses 204Pb nor assumes concordance, but uses a numeric solution to a set of equations relating the content of radiogenic lead in a zircon or other U/Th-enriched mineral to its total lead content.

TL;DR: In this article, the trace element distribution coefficients between zircon and garnet were analyzed for trace elements using LA-ICP-MS and SHRIMP ion microprobe.

TL;DR: A-type granites are widely distributed in northeastern China (NE China). They were emplaced during three major episodes (the Permian, late Triassic to early Jurassic, and early Cretaceous) and evolved in different tectonic regimes.

TL;DR: The discovery of the Rainbow hydrothermal field hosted in ultramafic rocks south of the Amar segment on the Mid-Atlantic ridge (MAR) was part of the MAST III-AMORES (1995-1998) program funded by the European Union.

TL;DR: In this paper, the most altered metavolcanic amphibolites (the Garbenschiefer unit) from the Central Tectonic Domain of the Isua greenstone belt are characterized by high Mg-number (060-080), MgO (7-18 wt%), Al2O3 (14-20 wt), Ni (60-645 ppm) and Cr (60−1920 ppm) contents, but low TiO2 (020-040 wt.), Zr (12-30 ppm), Y (6-14 ppm

TL;DR: In this paper, the authors collected from the Rainbow vent field (36°14′N) on the Mid-Atlantic Ridge (MAR) during the 1997 diving FLORES cruise, which is composed of ∼10 black smokers emitting acidic fluids at 365 °C.

TL;DR: In this article, sector-field inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the isotopic composition and concentration of uranium and thorium, focusing on the rare isotopes, 230Th and 234U.

TL;DR: In this paper, experiments were carried out to investigate the sorption of the complete lanthanide series (Ln or rare earth elements, REE) on a kaolinite and an a Na-montmorillonite at 22°C over a wide range of pH (3-9).

TL;DR: In this article, it was shown that the compositions of melt inclusions in early formed phenocrysts, often of most interest in petrological studies, can be affected by processes such as volatile dissociation, oxidation and/or partial re-equilibration with their host, both during natural cooling and during homogenisation experiments.

TL;DR: In this paper, the authors used solubility data for argon in hydrous fluids, melts and emerging data for minerals to understand the behaviour of excess argon, and provide valuable insights into the environment in which the samples cooled to their argon retention or closure temperature.

TL;DR: In this paper, the chemical status of major and trace elements (TE) in various boreal small rivers and watershed has been investigated along a 1500-km transect of NW Russia.

TL;DR: In this paper, major element and some trace element compositions (including the REE) of shales, carbonate-rich shales and limestones of Late Cretaceous age have been analyzed at two outcrops near Pueblo, CO.

TL;DR: In this paper, microprobe measurements of the concentrations of H2O, CO2, F, S and Cl and the isotopic composition of hydrogen are reported for populations of olivine-hosted melt inclusions from five lava samples from the Hawaiian volcanoes Loihi, Kilauea, Mauna Loa and Koolau.

TL;DR: In this article, secondary ion mass spectrometry (SIMS) is used to measure the abundances and isotopic compositions of hydrogen, carbon, fluorine, sulfur and chlorine in volcanic glasses.

TL;DR: In this paper, the authors investigated the properties of accessory allanite in the Dora-Maira massif and found that it is stabilised by the incorporation of light rare earth elements and was found up to temperatures of 1050 °C and to pressures of at least 4.5 GPa.

TL;DR: The chemistry of major elements (Ca, Mg, Na, K, HCO3, SO4, Cl, and Si) in the river water of the Changjiang (Yangtze River) was studied, based on continuously monitored data at 191 stations in the drainage basin for the period 1958-1990.

TL;DR: In this article, electron microprobe and laser ablation micro-probe (LAM) data for a range of high field strength (Zr, Nb, Mo, Sn, Sb, Hf, Ta, W) and other trace elements (Al, Si, Ca, V, Cr, Mn, Fe, Pb, Th, U) in rutile from eclogites and garnet mica schists from Trescolmen, Central Alps.

TL;DR: A comparison of oxygen isotope analyses of natural and synthetic phosphates using three methods in current use and Ag3PO4 as the analyte was made by as discussed by the authors, who concluded that conventional fluorination using BrF5 provides the most precise and accurate measurements.

TL;DR: In this article, the authors present a new assessment of the pre-anthropogenic U budget for the Holocene ocean and find that the gross input of U to the ocean lies in the range 53±17 Mmol/year, where the dominant source is river runoff (42.0±14.5 Mmol) and the direct discharge of groundwater could represent a significant additional input (9.3±8.7 Mmol).

TL;DR: In this article, a real-time mass bias correction is made by aspirating a Tl/U tracer at the same time as laser ablation, which is similar to that described in Horn et al. (2000), except that enriched 233U rather than 235U is used in the tracer solution Correction for laser-induced Pb/U elemental fractionation is based on a mathematical treatment of time-resolved data that is independent of laser-ablation characteristics.

TL;DR: In this paper, the mass bias for Tl is assumed to be similar to that of Pb, and the authors used a multicollector magnetic sector inductively coupled plasma mass spectrometers (ICP-MS) for Pb isotope analysis.

TL;DR: In this paper, the authors explore the effects of melt composition on activity coefficients of trace-element oxide components, and show no simple dependence on any particular major element oxide component, but show that the effect of melting composition can be largely eliminated if the ratios of two activity coefficients are taken, as for example, when two-element distribution coefficients are used.

TL;DR: In this article, abranched fragments (200-400 µm) of a large, chemically homogeneous, and non-metamict Brazilian monazite crystal, characterised by a concordant U-Pb ages of 474 +/- 1 Ma (208Pb/206Pb = 19.5), were hydrothermally treated at varying temperatures with solutions of different compositions.

TL;DR: In this paper, the authors investigated the influence of terrigenous sediments from the Yangtze River on the spatial variations of heavy metals and organic carbon on the East China Sea continental shelf.

TL;DR: In this paper, the radiogenic isotopic composition of both detrital and Fe-Mn fractions in marine sediments is used in paleoceanography to infer changes of bottom-water circulation.

TL;DR: In this article, the authors present Nd isotope data for standards and samples to obtain systematic information on the nature of the mass bias in inductively coupled mass spectrometers (ICPMS).

TL;DR: The Dabie Shan Ultrahigh-Pressure Metamorphic (UHPM) Belt has been used for dating of zircons and monazites in this paper.

TL;DR: In this paper, a multidisciplinary approach utilizing TIMS and laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) isotope data, quantitative and qualitative EMP chemical analyses of monazite, and textural studies, assess the significance of Pb loss, older components, and continuous and episodic monazites growth in the generation of dispersed age data.

TL;DR: The magnetite-apatite ores in the Kiruna area, northern Sweden, are generally considered to be of magmatic origin formed in a subvolcanic-volcanics environment during the early Proterozoic as mentioned in this paper.

TL;DR: In this paper, major, trace and rare earth element abundances were determined for the southwestern Japanese pelagic chert sequence from the early Late Permian to early Early Triassic to investigate a redox change in deep-sea pelagic environments before and at the Permo-Triassic boundary (PTB) (251 Ma).