CHEMICAL GEOLOGY化学地质学
CHEMICAL GEOLOGY(英文缩写 CHEM GEOL),ISSN 0009-2541,eISSN 1872-6836,中文译名:化学地质学 是一本学术期刊。本页汇总该期刊的最新影响因子、分区信息以及最新收录于 PubMed 的文献,帮助您快速了解期刊全貌。
发文量统计区间：2025-11-01 至 2026-10-31，按本站收录文献的发表日期统计。
期刊介绍
历年影响因子趋势
| JCR 数据年份 | 影响因子 | JCR 分区 |
|---|---|---|
| 2021 | 4.685 | Q1 |
| 2022 | 3.900 | Q1 |
| 2023 | 3.600 | Q1 |
| 2024 | 3.600 | Q1 |
| 2025 | 3.600 | Q1 |
CHEMICAL GEOLOGY 最新收录文献
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1. The preservation of francolite-associated sulfate in lingulid brachiopods.
PMID:日期:2026-06-28Lingulid brachiopods - the namesake "living fossils" of Darwin - have a continuous record from the Cambrian to the present and possess phosphatic valves, rendering them largely unique among extant invertebrates. Due to their poorly understood vital effects and susceptibility to taphonomic breakdown, they have not been widely adopted as geochemical archives. However, inorganic sulfate is abundant in lingulid bioapatite, which may be more resistant to diagenetic alteration than carbonate-based minerals. As such, it is possible that lingulid shells may provide an alternative, independent archive of Phanerozoic sulfate seawater chemistry, provided that the distribution and preservation of sulfur within lingulid shells can be identified. Here, we leverage sulfur K-edge micro X-ray Fluorescence (μ-XRF) imaging, X-ray Absorption Near Edge Structure (XANES) spectroscopy, and petrography to characterize sulfur speciation and distribution within extant and fossil lingulid brachiopods. In modern , inorganic sulfate is dominant along francolite-rich laminae, whereas organic sulfur species are mostly observed in non-mineralized laminae and the periostracum. In the Cambrian fossil , inorganic sulfate is generally dominant in regions with the lowest sulfur abundances, with higher sulfate abundances along compact laminae than on baculate laminae. In contrast, the distribution of diagenetic pyrite is heterogenous, although largely concentrated along shell edges and particular laminae. Notably, the XANES spectrum of francolite-associated sulfate is characterized by a unique post-edge feature at 2494.0 eV. Collectively, these results suggest that carefully selected lingulid specimens - and from intra-valve laminae with minimal diagenetic phases - have the potential to be insightful for reconstructing Phanerozoic sulfate seawater chemistry.
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2. Kinetics of Na- and K- uranyl arsenate dissolution.
PMID:日期:2023-07-26We integrated aqueous chemistry analyses with geochemical modeling to determine the kinetics of the dissolution of Na and K uranyl arsenate solids (UAs) at acidic pH. Improving our understanding of how UAs dissolve is essential to predict transport of U and As, such as in acid mine drainage. At pH 2, NaH(UO)(AsO)(HO) (NaUAs) and KH(UO)(AsO)(HO) (KUAs) both dissolve with a rate constant of 3.2 × 10 mol m s, which is faster than analogous uranyl phosphate solids. At pH 3, NaUAs (6.3 × 10 mol m s) and KUAs (2.0 × 10 mol m s) have smaller rate constants. Steady-state aqueous concentrations of U and As are similarly reached within the first several hours of reaction progress. This study provides dissolution rate constants for UAs, which may be integrated into reactive transport models for risk assessment and remediation of U and As contaminated waters.
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3. Magnesium isotope analysis of olivine and pyroxene by SIMS: Evaluation of matrix effects.
PMID:日期:2020-01-31The performance of multi-collector secondary ion mass spectrometry (MC-SIMS) for Mg isotope ratio analysis was evaluated using 17 olivine and 5 pyroxene reference materials (RMs). The Mg isotope composition of these RMs was accurately and precisely determined by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), and these measured isotope ratios were used to evaluate SIMS instrumental mass bias as a function of the forsterite (Fo) content of olivine. The magnitude of the Mg isotope matrix effects were ~3‰ in δMg, and are a complex function of olivine Fo content, that ranged from Fo to Fo. In addition to these Mg isotope matrix effects, Si ion yields and Mg/Si ion ratios varied as a complex function of the Fo content of the olivine RMs. For example, Si ion yields varied by ~33%. Based on the observations, we propose instrumental bias correction procedures for SIMS Mg isotope analysis of olivine using a combination of Mg/Si ratios and Fo content of olivine. Using this correction method, the accuracy of δMg analyses is 0.3‰, except for analysis of olivine with Fo where instrumental biases and Mg/Si ratios change dramatically with Fo content, making it more difficult to assess the accuracy of Mg isotope ratio measurements by SIMS over this narrow range of Fo content. Five pyroxene RMs (3 orthopyroxenes and 2 clinopyroxenes) show smaller ranges of instrumental bias (~1.4‰ in δMg) as compared to the olivine RMs. The instrumental bias for the 3 orthopyroxene RMs do not define a linear relationship with respect to enstatite (En) content, that ranged from En. The clinopyroxene RMs have similar En and wollastonite (Wo) contents but have δMg values that differ by 0.5‰ relative to their δMg values determined by MC-ICP-MS. These results indicate that additional factors (e.g., minor element abundances) likely contribute to SIMS instrumental mass fractionation. In order to better correct for these SIMS matrix effects, additional pyroxene RMs with various chemical compositions and known Mg isotope ratios are needed.
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4. Effect of Bicarbonate and Oxidizing Conditions on U(IV) and U(VI) Reactivity in Mineralized Deposits of New Mexico.
PMID:日期:2019-07-08We investigated the effect of bicarbonate and oxidizing agents on uranium (U) reactivity and subsequent dissolution of U(IV) and U(VI) mineral phases in the mineralized deposits from Jackpile mine, Laguna Pueblo, New Mexico, by integrating laboratory experiments with spectroscopy, microscopy and diffraction techniques. Uranium concentration in solid samples from mineralized deposit obtained for this study exceeded 7000 mg kg, as determined by X-ray fluorescence (XRF). Results from X-ray photoelectron spectroscopy (XPS) suggest the coexistence of U(VI) and U(IV) at a ratio of 19:1 at the near surface region of unreacted solid samples. Analyses made using X-ray diffraction (XRD) and electron microprobe detected the presence of coffinite (USiO) and uranium-phosphorous-potassium (U-P-K) mineral phases. Imaging, mapping and spectroscopy results from scanning transmission electron microscopy (STEM) indicate that the U-P-K phases were encapsulated by carbon. Despite exposing the solid samples to strong oxidizing conditions, the highest aqueous U concentrations were measured from samples reacted with 100% air saturated 10 mM NaHCO solution, at pH 7.5. Analyses using X-ray absorption spectroscopy (XAS) indicate that all the U(IV) in these solid samples were oxidized to U(VI) after reaction with dissolved oxygen and hypochlorite (OCl) in the presence of bicarbonate (HCO ). The reaction between these organic rich deposits, and 100% air saturated bicarbonate solution (containing dissolved oxygen), can result in considerable mobilization of U in water, which has relevance to the U concentrations observed at the Rio Paguate across the Jackpile mine. Results from this investigation provide insights on the reactivity of carbon encapsulated U-phases under mild and strong oxidizing conditions that have important implication in U recovery, remediation and risk exposure assessment of sites.
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5. Reactivity of As and U co-occurring in Mine Wastes in northeastern Arizona.
PMID:日期:2019-05-20The reactivity of co-occurring arsenic (As) and uranium (U) in mine wastes was investigated using batch reactors, microscopy, spectroscopy, and aqueous chemistry. Analyses of field samples collected in proximity to mine wastes in northeastern Arizona confirm the presence of As and U in soils and surrounding waters, as reported in a previous study from our research group. In this study, we measured As (< 0.500 to 7.77 μg/L) and U (0.950 to 165 μg/L) in waters, as well as mine wastes (< 20.0 to 40.0 mg/kg As and < 60.0 to 110 mg/kg U) and background solids (< 20.0 mg/kg As and < 60.0 mg/kg U). Analysis with X-ray fluorescence (XRF) and electron microprobe show the co-occurrence of As and U with iron (Fe) and vanadium (V). These field conditions served as a foundation for additional laboratory experiments to assess the reactivity of metals in these mine wastes. Results from laboratory experiments indicate that labile and exchangeable As(V) was released to solution when solids were sequentially reacted with water and magnesium chloride (MgCl), while limited U was released to solution with the same reactants. The predominance of As(V) in mine waste solids was confirmed by X-ray absorption near edge (XANES) analysis. Both As and U were released to solution after reaction of solids in batch experiments with HCO . Both X-ray photoelectron spectroscopy (XPS) and XANES analysis determined the predominance of Fe(III) in the solids. Mössbauer spectroscopy detected the presence of nano-crystalline goethite, Fe(II) and Fe(III) in (phyllo)silicates, and an unidentified mineral with parameters consistent with arsenopyrite or jarosite in the mine waste solids. Our results suggest that As and U can be released under environmentally relevant conditions in mine waste, which is applicable to risk and exposure assessment.
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6. {"_":"Determinants of blood water O variation in a population of experimental sheep: implications for paleoclimate reconstruction.","i":["δ"],"sup":["18"]}
PMID:日期:2018-03-26Mammalian body, blood and hard tissue oxygen isotope compositions ( O values) reflect environmental water and food sources, climate, and physiological processes. For this reason, fossil and archaeological hard tissues, which originally formed in equilibrium with body chemistry, are a valuable record of past climate, landscape paleoecology, and animal physiology and behavior. However, the environmental and physiological determinants of blood oxygen isotope composition have not been determined experimentally from large herbivores. This class of fauna is abundant in Cenozoic terrestrial fossil assemblages, and the isotopic composition of large herbivore teeth has been central to a number of climate and ecological reconstructions. Furthermore, existing models predict blood water, or nearly equivalently body water, O values based on environmental water sources. These have been evaluated on gross timescales, but have not been employed to track seasonal variation. Here we report how water, food, and physiology determine blood water O values in experimental sheep () subjected to controlled water switches. We find that blood water O values rapidly reach steady state with environmental drinking water and reflect transient events including weaning, seasons, and snowstorms. Behavioral and physiological variation within a single genetically homogenous population of herbivores results in significant inter-animal variation in blood water O values at single collection times (1 s.d. = 0.1-1.4 ‰, range = 3.5 ‰) and reveals a range of water flux rates ( = 2.2-2.9 days) within the population. We find that extant models can predict average observed sheep blood O values with striking fidelity, but predict a pattern of seasonal variation exactly opposite of that observed in our population for which water input variation was controlled and the effect of physiology was more directly observed. We introduce to these models an evaporative loss term that is a function of environmental temperatures. The inclusion of this function produces model predictions that mimic the observed seasonal fluctuations and match observations to within 1.0 ‰. These results increase the applicability of available physiological models for paleoseasonality reconstructions from stable isotope measurements in fossil or archaeological enamel, the composition of which is determined in equilibrium with blood values. However, significant blood O variation in this experimentally controlled population should promote caution when interpreting isotopic variation in the archaeological and paleontological record.
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7. Determination of Cr(III) solids formed by reduction of Cr(VI) in a contaminated fractured bedrock aquifer: Evidence for natural attenuation of Cr(VI).
PMID:日期:2017-12-10Hexavalent chromium Cr(VI) is toxic and can be highly mobile in many aquifer systems. Redox reactions with naturally occurring minerals and organic compounds can reduce Cr(VI) to Cr(III), forming labile Cr(III) oxyhydroxide precipitates, which is a natural attenuation process. In fractured bedrock aquifers, reduction of Cr(VI) in the rock matrix can enhance attenuation beyond that from matrix diffusion only, and potentially reduce back diffusion if concentrations in fractures decline following source reduction via natural processes or engineered remediation. In this study, we develop an extraction method for labile Cr(III) precipitates from Cr(VI) reduction using 5% hydrogen peroxide (HO). Combining Cr(III) extractions with an established sodium hydroxide (NaOH) method for determination of Cr(VI) concentrations in rock porewater, a measure of the labile Cr(III) and Cr(VI) fractions in geologic samples is achieved. The methods were applied to cores from a contaminated groundwater system in fractured porous bedrock in order to assess the effectiveness of natural attenuation and whether Cr(VI) mass that diffused into the bedrock matrix was undergoing reduction. Detailed vertical distributions display two depth intervals with corresponding elevated concentrations of Cr(VI) in the porewater and extractable total Cr. The correspondence of Cr(VI) and labile Cr(III) provides evidence for reduction of Cr(VI) contamination in the bedrock matrix. Mineralogical analysis suggests that Fe(II)-bearing minerals, chlorite and biotite are the most likely candidates for natural reductants. This study provides evidence for the natural attenuation of anthropogenic Cr(VI) contamination in the porewater of a fractured bedrock aquifer, and it outlines a quantitative method for evaluating the effectiveness of natural attenuation in groundwater systems.
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8. Simultaneously Quantifying Ferrihydrite and Goethite in Natural Sediments Using the Method of Standard Additions with X-ray Absorption Spectroscopy.
PMID:日期:2017-11-21The presence of ferrihydrite in sediments/soils is critical to the cycling of iron (Fe) and many other elements but difficult to quantify. Extended X-ray absorption fine structure (EXAFS) spectroscopy has been used to speciate Fe in the solid phase, but this method is thought to have difficulties in distinguishing ferrihydrite from goethite and other minerals. In this study, both conventional EXAFS linear combination fitting (LCF) and the method of standard-additions are applied to the same samples in attempt to quantify ferrihydrite and goethite more rigorously. Natural aquifer sediments from Bangladesh and the United States were spiked with known quantities of ferrihydrite, goethite and magnetite, and analyzed by EXAFS. Known mineral mixtures were also analyzed. Evaluations of EXAFS spectra of mineral references and EXAFS-LCF fits on various samples indicate that ferrihydrite and microcrystalline goethite can be distinguished and quantified by EXAFS-LCF but that the choice of mineral references is critical to yield consistent results. Conventional EXAFS-LCF and the method of standard-additions both identified appreciable amount of ferrihydrite in Bangladesh sediments that were obtained from a low-arsenic Pleistocene aquifer. Ferrihydrite was also independently detected by sequential extraction and Fe Mӧssbauer spectroscopy. These observations confirm the accuracy of conventional EXAFS-LCF and demonstrate that combining EXAFS with additions of reference materials provides a more robust means of quantifying short-range-ordered minerals in complex samples.
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9. Uptake of nickel by synthetic mackinawite.
PMID:日期:2017-06-25The uptake of aqueous Ni(II) by synthetic mackinawite (FeS) was examined in anaerobic batch experiments at near-neutral pH (5.2 to 8.4). Initial molar ratios of Ni(II) to FeS ranged from 0.008 to 0.83 and maximum Ni concentrations in mackinawite, expressed as the cation mol fraction, were as high as = 0.56 (Fe Ni S; 0 ≤ ≤ 1). Greater than 99% Ni removal from solution occurred when Ni loading remained below 0.13 ± 0.03 (1) mol Ni per mol FeS due to sorption of Ni at the mackinawite surface. Characterization of experimental solids using X-ray diffraction and Raman spectroscopy showed patterns characteristic of nanocrystalline mackinawite; no evidence of nickel monosulfide (α-NiS or millerite), polydymite (NiS), or godlevskite [(Ni,Fe)S] formation was indicated regardless of the amount of Ni loading. Slight expansion of the -axis correlated with increasing Ni content in synthetic mackinawite, from = 5.07 ± 0.01 Å at = 0.02 to = 5.10 ± 0.01 Å at = 0.38. Ni -edge extended X-ray absorption fine structure (EXAFS) spectra of synthetic Ni-bearing mackinawite are similar in phase and amplitude to the Fe -edge EXAFS spectrum of Ni-free mackinawite, indicating that the molecular environment of Ni in Ni-bearing mackinawite is similar to that of Fe in Ni-free mackinawite. EXAFS data fitting of Ni-bearing mackinawite with = 0.42 indicated a coordination number of 4.04 ± 0.30 and an average Ni_S bond distance of 2.28 Å, in good agreement with the Fe_S bond distance of 2.26 Å in mackinawite, tetrahedral Fe coordination, and slight lattice expansion along the -axis. At lower Ni loadings ( = 0.05-0.11), EXAFS analysis showed a decrease in Ni_S coordination towards CN = 3, which reflects the influence of sorbed Ni. Continued Ni uptake, past the maximum amount of sorption, was accompanied by proportional molar release of Fe to solution. Interstitial occupancy of Ni within the mackinawite interlayer may be transitional to structural substitution of Fe. The Ni-mackinawite solid-solution is described by a one-site binary mixing model: where is the distribution coefficient, is the ratio of equilibrium constants for Ni-mackinawite and mackinawite (14.4 ± 1.3), is an ion interaction parameter, and is the mole fraction of end-member NiS in the solid solution. The experimentally determined value of is 17.74 ± 1.15 kJ/mol and indicates significant non-ideality of the solid solution. Transformation processes were evaluated by aging Ni-mackinawite with polysulfides and solutions saturated with air. Reaction of Ni-mackinawite with polysulfides led to the formation of pyrite (FeS) and Ni retention in the solid phase. When Ni-mackinawite was aged in the presence of dissolved oxygen, transformation to goethite (FeOOH) and violarite (FeNiS) was observed.
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10. {"_":" nanoscale observations of gypsum dissolution by digital holographic microscopy.","i":["In situ"]}
PMID:日期:2017-04-17Recent topography measurements of gypsum dissolution have not reported the absolute dissolution rates, but instead focus on the rates of formation and growth of etch pits. In this study, the absolute retreat rates of gypsum (010) cleavage surfaces at etch pits, at cleavage steps, and at apparently defect-free portions of the surface are measured in flowing water by reflection digital holographic microscopy. Observations made on randomly sampled fields of view on seven different cleavage surfaces reveal a range of local dissolution rates, the local rate being determined by the topographical features at which material is removed. Four characteristic types of topographical activity are observed: 1) smooth regions, free of etch pits or other noticeable defects, where dissolution rates are relatively low; 2) shallow, wide etch pits bounded by faceted walls which grow gradually at rates somewhat greater than in smooth regions; 3) narrow, deep etch pits which form and grow throughout the observation period at rates that exceed those at the shallow etch pits; and 4) relatively few, submicrometer cleavage steps which move in a wave-like manner and yield local dissolution fluxes that are about five times greater than at etch pits. Molar dissolution rates at all topographical features except submicrometer steps can be aggregated into a continuous, mildly bimodal distribution with a mean of 3.0 µmolm s and a standard deviation of 0.7 µmolm s.