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Molar-Tooth Carbonate: An excellent proxy for reconstructing lithium isotopic composition of Precambrian seawater Chem. Geol. (IF 3.9) Pub Date : 2024-03-12 Tingyu Yang, Yilin Xiao, Yang-Yang Wang, Hongwei Kuang, Jack Geary Murphy, Erhao Shan, Ling-Ling Jiang, Xiangying Ye, He Sun, Haiou Gu
Shallow water carbonates are extensively utilized as archives for reconstructing past seawater chemistry and understanding global geochemical cycles. However, their reliability is often compromised by diagenetic alteration, obscuring primary environmental signals. Molar-tooth carbonate (MTC) exhibits exceptional resistance to diagenesis compared to other carbonate minerals, making it a promising candidate
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Testing the reproducibility of in situ Lu[sbnd]Hf dating using Lu-rich garnet from the Tørdal pegmatites, southern Norway Chem. Geol. (IF 3.9) Pub Date : 2024-03-12 Stijn Glorie, Alexander Simpson, Sarah E. Gilbert, Martin Hand, Axel B. Müller
In situ LuHf geochronology offers the potential for direct dating of garnet within petrographic context. However, the method requires matrix-matched standards to calibrate measured Lu/Hf ratios. In order to assess the accuracy of this calibration, as well as the reproducibility of the resulting LuHf dates, two Lu-rich (up to 1 wt% Lu) garnet samples from the Tørdal pegmatite field in southern Norway
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Post-cratering melting of target rocks at the impact melt contact: Observations from the Vredefort impact structure, South Africa Chem. Geol. (IF 3.9) Pub Date : 2024-03-12 M.S. Huber, E. Kovaleva, D.A. Zamyatin, A.A. Davletshina, V. Fernandez, T. Salge
Impact melt is generated following hypervelocity impact events. Emplacement of impact melt dikes, such as the Vredefort Granophyre Dikes, allow for this high temperature melt to come into contact with deeply-buried target rocks after the cratering process is completed. Our study analyzes the effects of this interaction by examining the direct contact between the Vredefort Granophyre and the granitic
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Fluid-mediated exchange reaction induces clumped isotope resetting: Insights from aragonite dolomitization experiments Chem. Geol. (IF 3.9) Pub Date : 2024-03-11 Yangrui Guo, Kai Kong, Xi Liu, Wenfeng Deng, Gangjian Wei
Carbon and oxygen isotopic exchange between external and internal fluids of carbonate minerals can reset the clumped isotope composition (Δ) of paleotemperature archives. Understanding the nature of this exchange during carbonate diagenetic alterations is essential for correctly interpreting the paleoenvironmental significance of Δ-derived temperatures. Through batch hydrothermal experiments on aragonitic
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Are sulfides the primary host of sedimentary Hg? A case study from the lower Jurassic of the Surat Basin (Australia) Chem. Geol. (IF 3.9) Pub Date : 2024-03-11 Yuqing Zhu, Andrew La Croix, David B. Kemp, Jun Shen, Chunju Huang, Xia Hua, Yu Li, Mengchuang Wei
Several mass extinction events and major paleoenvironmental perturbations during the Phanerozoic have been linked to massive volcanic eruptions, especially those associated with large igneous province (LIP) emplacement. Because magmatism during LIPs can be accompanied by the release and widespread dispersal of mercury (Hg), Hg concentration in sedimentary rocks has proven to be a useful proxy for paleovolcanism
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Influence of goethite nanophase on rare-earth element patterns and enrichment in marine phosphates during early diagenesis Chem. Geol. (IF 3.9) Pub Date : 2024-03-09 Jieqi Xing, Shan Li, Hongyan Wei, Jiaxin Xi, Xiaoju Lin, Yiping Yang, Haiyang Xian, Wei Tan, Jingming Wei, Jianxi Zhu
Although rare-earth elements (REEs) in authigenic phosphates and carbonates derived from marine sediments are potential proxies (e.g., REE patterns) for reconstructing paleoenvironmental conditions, the REE patterns appear to be inconsistent. Some marine authigenic phosphates show a “bell-shaped” pattern with an enrichment of the middle REEs (MREEs; NdHo), while others exhibit a “modern seawater-like”
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Trace elements in coralline algae as a new proxy for seawater chemistry and metal pollution Chem. Geol. (IF 3.9) Pub Date : 2024-03-08 Jean-Alix Barrat, Laurent Chauvaud, Erwan Amice, Jacques Grall, Marie-Laure Rouget, Germain Bayon, Yoan Germain
The abundances of some macronutrients, and trace elements (K, Al, P, V, Mn, Co, Ni, Cu, Zn, Rb, Sr, Mo, Cs, Ba, Pb, Th, U, Y and REE) were determined in a series of coralline algae () samples ( = 101) collected alive in the Bay of Brest and the Iroise Sea (Western Brittany, NW France), in order to assess the potential of these algae as archives of seawater chemistry and potential metal pollution. REY
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Isomorphic substitution behavior of Pt on synthetic vernadite (δ-MnO2):A model reaction to elucidate the mechanism of Pt enrichment in marine ferromanganese crust Chem. Geol. (IF 3.9) Pub Date : 2024-03-08 Zhengkun Li, Xiaoming Sun, Dengfeng Li, Fei Huang, Yongjia Liang
Marine ferromanganese crusts are considered to be the potential Pt deposits, and recent studies report a strong association between Pt and vernadite in these crusts. However, there are still uncertainties regarding the molecular processes involved in the enrichment of Pt by vernadite. This study investigates the adsorption behavior and molecular-scale immobilization mechanisms of Pt at water/vernadite
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Short chain tricyclic terpanes as organic proxies for paleo-depositional conditions Chem. Geol. (IF 3.9) Pub Date : 2024-03-07 Hong Xiao, Meijun Li, Benjamin J. Nettersheim
Reconstructing the paleo-environmental conditions that prevailed during the deposition of sediments provides invaluable information for paleo-ecological and evolutionary reconstructions and petroleum exploration. However, reconstructions of depositional environments based on sedimentary structures are often ambiguous, in particular if only core or mud chip samples are available. Organic proxies provide
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Pyrochlore composition and Sm[sbnd]Nd isotope signature as indicators of magmatic-hydrothermal processes: The case of Ririwai complex, north-Central Nigeria Chem. Geol. (IF 3.9) Pub Date : 2024-03-06 Yuxiang Zhu, Lianxun Wang, Yuanming Pan, Chao Zhang, Renat R. Almeev, Zhenbing She, François Holtz
This study presents a geochemical and SmNd isotopic study on pyrochlore from the Ririwai alkaline complex in north-central Nigeria, aiming to reconstruct the magmatic-hydrothermal history and provide insights into the formation of niobium deposit hosted in alkaline igneous rocks. Three texturally and compositionally distinct types of pyrochlore (Pcl I, II, and III) are identified. Primary Pcl I grains
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The source and ore-forming processes of post-collisional Qulong porphyry Cu-Mo deposit in Tibet constrained by Mo isotopes Chem. Geol. (IF 3.9) Pub Date : 2024-03-06 Qiqi Xue, Lipeng Zhang, Shuo Chen, Congying Li, Tao Li, Weidong Sun
Porphyry deposits supply most of the world's Cu and Mo resources. Most porphyry deposits are developed in magmatic arcs above subduction zones. However, abundant Miocene porphyry Cu-Mo deposits have been found in the post-collision stage in Tibet, more than ∼30 Myr after the Indian-Eurasian continental collision. The magma source and the enrichment process of ore-forming elements for these post-collision
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Biomarker evidence for wildfire activity in surface soils from Mt. Yulong on the southeastern Tibetan Plateau: Sources and controls Chem. Geol. (IF 3.9) Pub Date : 2024-03-05 Yangzhuang Li, Yan Bai, Chihao Chen, Qinghu Chen, Xiaomin Fang, Xiaoming Liu, Zhijun Liu
Forest fires have become more frequent in many regions throughout the world over recent decades, principally as a result of global warming. Polycyclic aromatic hydrocarbons (PAH) have become recognized as a byproduct of wildfires and an important indicator of ancient wildfires. However, the factors controlling wildfires remain elusive. This study presents analyses of PAH compounds found in 22 surface
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Distribution of 3-hydroxy fatty acids in South China Sea since the last deglaciation: Applicability of 3-hydroxy fatty acid-based palaeothermometry Chem. Geol. (IF 3.9) Pub Date : 2024-03-04 Yinwei Xi, Liuyan Wang, Yasong Wang, Huangmin Ge, Mingxing Zhang, Shengjie Ye, Xueqin Zhao, Yunping Xu
3-Hydroxy fatty acids (3-OH-FAs) are biomarkers for Gram-negative bacteria. Recent research has suggested that they could serve as temperature proxies in both terrestrial and marine environments, based on calibrations using modern samples. However, these proxies have been only applied in a speleothem for the Holocene and a short sediment core in the East China Sea for past 58 years, thus more evidence
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Seawater contamination by coring and pore water sampling of marine sediments Chem. Geol. (IF 3.9) Pub Date : 2024-03-01 Bo Barker Jørgensen, Matthias Egger, Mark A. Lever, Hans Røy
Coring of sediments with minimal physical disturbance, and sampling of pore water with minimal contamination from seawater, are critical in marine geochemistry and microbiology. Yet, sediment coring generally causes smearing of sediment down along the inside of the core liner and leaves seawater and fluid mud trapped around the core. This seawater is a source of diffusive or advective exchange of solutes
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Stable hydrogen and oxygen isotope geochemistry of Fe3+-rich, interstratified clay minerals from seafloor hydrothermal sites Chem. Geol. (IF 3.9) Pub Date : 2024-03-01 Fred J. Longstaffe, Javier Cuadros, Joseph R. Michalski, Vesselin Dekov
Chemical and structural complexities in interstratified clay minerals arising from mineral transformations and evolving formation conditions should be recorded in their stable isotope signatures. This paper examines the controls on the stable hydrogen and oxygen isotope compositions of Fe-rich, glauconite-nontronite, talc-nontronite and talc-saponite from submarine hydrothermal sites, with a focus
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Discriminating quartz host rock based on its trace element chemistry using machine learning-a new tool for sedimentary provenance studies Chem. Geol. (IF 3.9) Pub Date : 2024-02-29 Rupashree Saha, Dewashish Upadhyay, Biswajit Mishra
Quartz is one of the most abundant mineral in the continental crust, occurring in a wide variety of igneous, metamorphic, and sedimentary rocks. It incorporates several trace elements such as Ti, Al, Li, Ge, B, and P in its structure during crystallization/precipitation from magma/fluid, which can potentially be used as petrogenetic indicators. Being physically and chemically resilient during sedimentary
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The influence of peritectic garnets on magnesium isotopic composition during crustal anatexis: Constraints from TTG-like leucosomes from the North Qaidam orogen, China Chem. Geol. (IF 3.9) Pub Date : 2024-02-28 Lintao Wang, Shengyao Yu, Dongyong Li, Guozheng Sun, Chuanzhi Li, Yinbiao Peng, Xiaocong Jiang, Xingzhou Jiang, Long Chen, Xiaohui Li, Yongjiang Liu, Sanzhong Li
Tonalitic–trondhjemitic–granodiorite (TTG)-like leucosomes, which are formed from anatectic melts, record crustal growth and evolution and thus provide constraints on the process of anatexis. However, potential Mg isotope disequilibrium during crustal anatexis makes interpreting the genesis of anatectic melts challenging, thereby potentially hindering the application of the Mg isotope system in investigations
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SPORA, a new silver phosphate precipitation protocol for oxygen isotope analysis of small, organic-rich bioapatite samples Chem. Geol. (IF 3.9) Pub Date : 2024-02-28 Gabriele Larocca Conte, Lauren E. Lopes, Aric H. Mine, Robin B. Trayler, Sora L. Kim
Isotopic analysis of phosphate oxygen from bones and teeth (O/O, δO) is a common tool used to investigate modern and ancient ecosystems and their climate. However, existing methods have expanded to use pretreatments for organic removal, require large sample sizes, or require extended precipitation timing. All together, these factors could affect accuracy and precision of δO measurement by promoting
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Controls on pyrite sulfur isotopes during early diagenesis in marine sediments of the South China Sea Chem. Geol. (IF 3.9) Pub Date : 2024-02-25 Xinyu Jiang, Shanggui Gong, Tao Sun, Jörn Peckmann, Gilad Antler, Yu Hu, Xudong Wang, Qianyong Liang, Dong Feng
Understanding the controls on the sulfur isotope compositions of syndepositional pyrite (δS) during early diagenesis is critical for environmental reconstructions, especially for the reconstruction of the marine sulfur cycle. Commonly, δS values increase with depth in marine sediments; this phenomenon has been extensively studied, fostering the reconstruction of both global and regional depositional
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High-precision analysis of carbon isotopic composition for individual CO2 inclusions via Raman spectroscopy: Addressing issues arising from the laser-heating effects Chem. Geol. (IF 3.9) Pub Date : 2024-02-24 Hao Wang, Wanjun Lu, Wenjing Wang, Qianghao Liu, Junji Yamamoto
The carbon isotopic composition of carbon dioxide fluid inclusions trapped within minerals reflects the origin and evolution of the CO-bearing fluids and melts. Recently, we developed a highly accurate method using Raman spectroscopy to determine the carbon isotopic composition of CO fluid inclusions, by simultaneously collecting CO and hot bands at a controlled temperature, and using the peak height
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Sources of Li isotope bias during SIMS analysis of standard glasses Chem. Geol. (IF 3.9) Pub Date : 2024-02-24 Adam C. Denny, Mindy M. Zimmer, Heather S. Cunningham, Natalie E. Sievers
The Li/Li ratios in fourteen USGS, MPI-DING, and NIST glass reference materials (RMs) were analyzed by LG-SIMS to assess compositional matrix effects, evaluate RM δLi homogeneity, and calculate the useful yield of lithium in silicate glasses. The analyzed RMs cover a range of SiO contents from 45.5 to 75.6% (komatiite to rhyolite), the largest compositional range yet evaluated for δLi matrix effects
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Decoding the signals of sediment weathering: Toward a quantitative approach Chem. Geol. (IF 3.9) Pub Date : 2024-02-24 Yulong Guo, Yalong Li, Kai Deng, Zhongbo Wang, Shouye Yang
In order to better interpret the signals of weathering intensity recorded in terrigenous sediment archives, it is essential to appropriately assess the effects of hydrodynamic sorting and sedimentary recycling. To achieve this, we utilized a compiled dataset of major element geochemistry of river sediments from East Asia to develop a quantitative index for evaluating the extent of quartz enrichment
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CO2 flux from the French Massif Central groundwaters: Modelling and quantitative estimation of the degassing process Chem. Geol. (IF 3.9) Pub Date : 2024-02-24 Lisa Ricci, Francesco Frondini, Daniele Morgavi, Marino Vetuschi Zuccolini, Guillaume Boudoire, Mickael Laumonier, Stefano Caliro, Carlo Cardellini, Artur Ionescu, Alessandra Ariano, Giovanni Chiodini
Passive rift systems are often characterized by CO degassing, witnessed by the presence of mineral and thermal springs, bubbling pools, mofetes. Despite these field manifestations, the quantitative estimation of the CO budget released to the atmosphere from these geodynamic structures is not well constrained. Here, we examine the chemistry of 169 springs, the isotopic composition of the dissolved carbon
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Vertical variations of bacteriohopanepolyols near the Changjiang Estuary waters: Implications for marine hypoxia and bacterial activities Chem. Geol. (IF 3.9) Pub Date : 2024-02-24 Meiling Yin, Liqin Duan, Jinming Song, Jiawei Kan, Huamao Yuan, Xuegang Li, Yingxia Wang
Bacteriohopanepolyols (BHPs) are widespread in bacteria and are used as lipid biomarkers for specific bacterial activities and environmental changes. However, deposition and degradation dynamics of BHPs are still poorly constrained in marine settings, thereby affecting their reliability as biomarkers. Here, we investigated BHPs in the water columns and sediments near the Changjiang Estuary to evaluate
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The onset of fluid-induced alteration of fluorapatite in iron oxide-apatite deposits: Insights from fluorapatite and their monazite inclusions at the Heiyingshan iron deposit, Beishan Metallogenic Belt, Northwest China Chem. Geol. (IF 3.9) Pub Date : 2024-02-23 Yong Yin, Hao Hu, Xiao-Dong Deng, Daniel Harlov, Jian-Wei Li, Zhuang Duan, Zhe-Jian Pan, David R. Lentz
Iron oxide-apatite (IOA) deposits generally undergo extensive late-stage metasomatic overprinting that modifies the texture and geochemistry of the magnetite, apatite, and other ore-forming minerals. However, the onset of metasomatism in IOA deposits worldwide generally remains poorly constrained. The Heiyingshan IOA deposit is located in the Beishan area of the Central Asian Orogenic Belt, NW China
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A discussion on carbon and oxygen isotopes of secondary carbonates in loess-paleosol sequences Chem. Geol. (IF 3.9) Pub Date : 2024-02-23 Xi Luo, Weiguo Liu, Zhisheng An
Although carbon and oxygen isotopic compositions of carbonates are valuable for Quaternary climate reconstruction due to their sensitivity to paleoclimate changes, a comprehensive understanding regarding the formation, factors influencing isotopic variations, and age uncertainties of secondary carbonates in loess deposits remains elusive. This study investigates the microstructure and stable isotopes
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An accurate model for the solubilities of anhydrite in H2O–NaCl solutions at temperatures up to 1073 K, pressures up to 14,000 bar, and mole fractions of NaCl up to 0.3 Chem. Geol. (IF 3.9) Pub Date : 2024-02-22 Qingqing Wang, Lin Zhang, Jiawen Hu, Xunli Shi
An accurate density-based solubility model is established for anhydrite in HO–NaCl solutions, which is valid for temperatures up to 1073 K, pressures up to 14,000 bar, and mole fractions of NaCl () up to 0.3. The isobaric linear dependence of the mineral solubility logarithm on the solvent density logarithm should be a common phenomenon similar to isothermal linear dependence, particularly at relatively
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Cadmium isotope composition of the Earth's mantle inferred from analysis of oceanic basalts and komatiites Chem. Geol. (IF 3.9) Pub Date : 2024-02-22 Gabriel Devos, Frédéric Moynier, John Creech, Deze Liu, Igor S. Puchtel, Martin Bizzarro
Cadmium stable isotope ratios can serve as valuable tracers for biological and geological processes, including nutrients sampling from the surrounding medium, volatilization events, and terrestrial differentiation. However, studies of the isotope fractionation occurring during geological processes require the characterization of the isotope compositions of the different terrestrial reservoirs. Notably
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Tracking element-mineral associations with unsupervised learning and dimensionality reduction in chemical and optical image stacks of thin sections Chem. Geol. (IF 3.9) Pub Date : 2024-02-22 Marco A. Acevedo Zamora, Balz S. Kamber, Michael W.M. Jones, Christoph E. Schrank, Chris G. Ryan, Daryl L. Howard, David J. Paterson, Teresa Ubide, David T. Murphy
In-situ chemical analysis on thin sections is a cornerstone of geochemical research. Despite massive advances in digital image analysis, the interpretation of such data within the optical petrological context of the thin section has largely remained an analogue task in geochemistry. In this contribution, we registered optical and micro-chemical images from large thin section areas. Chemical datasets
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Coupled carbon‑iron‑phosphorus cycling in the Rainbow hydrothermal vent field Chem. Geol. (IF 3.9) Pub Date : 2024-02-17 Kristin Anna Ungerhofer, Oliver Plümper, Martina Preiner, Gert-Jan Reichart, Peter Kraal
Hydrothermal venting has been shown to play a role in the global biogeochemical cycles of three bio-essential elements: iron (Fe), carbon (C) and phosphorus (P). However, our insight into the coupled cycling of Fe and associated C and P in hydrothermal plumes as well as their long-term fate in the underlying sediments remains limited. We present a detailed study, tracing the biogeochemical pathways
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Dissolved Mn2+ promotes microbially-catalyzed protodolomite precipitation in brackish oxidized water Chem. Geol. (IF 3.9) Pub Date : 2024-02-12 Zuozhen Han, Jie Li, Yanyang Zhao, Qingyuan Chen, Xiao Gao, Kaiming Hu, Na Guo, Xiangyu Wei, Ruirui Meng, Chenlin Zhu, Maurice E. Tucker, Chao Han
Manganese (Mn) is a common trace element in dolomite, yet its precise role in dolomite precipitation, if any, has not been explored. This study aims to investigate carbonate mineral formation in the presence of extracellular polymeric substances produced by Y in 14 cross-over experiments within the MgCl-CaCl-MnCl system. The study involved the analysis and comparison of water chemistry, mineralogy
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Reductive sorption of vanadium by iron monosulfide in seawater Chem. Geol. (IF 3.9) Pub Date : 2024-02-10 Felicia J. Haase, Colton J. Vessey, Ryo Sekine, Nicholas J.C. Doriean, David T. Welsh, Joseph A. Otte, Jessica Hamilton, Donald E. Canfield, Yun Wang, Enzo Lombi, William W. Bennett
Vanadium (V) is a promising paleo-redox tracer in ancient marine sediments due its range of possible oxidation states (+3 to +5) and its unique redox-sensitivity. However, the interactions between V and the sulfide minerals common under ancient depositional conditions remain poorly studied. Iron monosulfide (FeS) is the first sulfide phase to form in anoxic-sulfidic waters and sediments, and an important
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Olenekian sulfur isotope records: Deciphering global trends, links to marine redox changes and faunal evolution Chem. Geol. (IF 3.9) Pub Date : 2024-02-10 Oluwaseun Edward, Jorge E. Spangenberg, Marc Leu, Charline Ragon, Sandrine Le Houedec, Aymon Baud, Hugo Bucher, Torsten Vennemann
The sulfur (S) isotope composition of carbonate associated sulfate (CAS) in carbonate rocks has been used to assess variations in paleo-oceanographic redox conditions and its relationship to biotic changes in Earth's history, including the Smithian – Spathian transition. However, previous CAS studies of the Olenekian are mostly based on nearshore continental shelf sections and report highly variable
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Fluid loss to the fore-arc controls the recycling efficiency of nitrogen in subduction zones Chem. Geol. (IF 3.9) Pub Date : 2024-02-09 Michael W. Förster, Chunfei Chen, Stephen F. Foley, Olivier Alard, Gregory M. Yaxley
Nitrogen is a crucial element for life on Earth as it dominates the planet's atmosphere and is present in the deep geological cycle. Previous studies have shown that nitrogen quickly degasses during melting, leaving behind a nitrogen-depleted residue. Nitrogen-rich igneous rocks are rare, whereas diamonds commonly contain appreciable nitrogen: these probably originate from domains enriched with recycled
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Mica Rb-Sr dating by laser ablation ICP-MS/MS using an isochronous calibration material and application to West African kimberlites Chem. Geol. (IF 3.9) Pub Date : 2024-02-07 Andrea Giuliani, Senan Oesch, Marcel Guillong, Geoffrey H. Howarth
RbSr dating of mica by laser ablation ICP-MS/MS has recently emerged as a new tool to date a range of geological processes including magmatic, metamorphic and hydrothermal events. The majority of age results presented to date are based on Rb/Sr calibration using the MicaMG pressed nano-powder pellet. However, some studies have reported low accuracy associated with mica RbSr ages using this method,
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Mechanistic insight into the electron transfer from Fe(II) minerals to quinones Chem. Geol. (IF 3.9) Pub Date : 2024-02-06 Yingxiao Tian, Peng Zhang, Songhu Yuan
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Extensive H2O degassing in deeply erupted submarine glasses inferred from Samoan melt inclusions: The EM2 mantle source is damp, not dry Chem. Geol. (IF 3.9) Pub Date : 2024-02-05 Olivia E. Anderson, Matthew G. Jackson, Ayla S. Pamukçu, Estelle F. Rose-Koga, Véronique Le Roux, Frieder Klein, Kenneth T. Koga, Glenn A. Gaetani, Allison A. Price
Submarine glasses erupted at intraplate volcanic hotspot settings sampling enriched mantle (EM)—characterized by high Sr/Sr—exhibit lower HO/Ce than glasses representing less enriched mantle domains, leading to the interpretation that the EM mantle is HO-poor (“dry”). We test whether low HO/Ce observed in pillow glasses of EM lavas resulted from degassing of higher HO/Ce primary melts by measuring
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Iron oxides (oxyhydroxides) associated with biogenic iron-organic framework structures in deep-sea hydrothermal vents of the Indian Ocean Chem. Geol. (IF 3.9) Pub Date : 2024-02-05 Kaiwen Ta, Shun Chen, Mengran Du, Jiwei Li, Hengchao Xu, Shuangquan Liu, Wanli Chen, Zijun Wu, Xiaotong Peng
The important geological, environmental, and biological information contained in Fe-oxides (oxyhydroxides) in extreme hydrothermal environments has provided unique opportunities for exploring the microbial-driven mechanism of Fe-oxide formation. However, the interactions between Fe-oxides and organic components and their association with geochemical signatures in hydrothermal systems remain poorly
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Aquatic plants dominate the sources of long-chain n-alkanes in floodplain lakes in the middle and lower reaches of the Yangtze River Chem. Geol. (IF 3.9) Pub Date : 2024-01-30 Xiaofang Yu, Mingming Zhang, Guang Yang, Linghan Zeng, Xu Chen, Xiaoxia Lü, Xianyu Huang
It has been generally accepted that long-chain n-alkanes found in lacustrine sequences are mainly derived from terrestrial plants, which is the basis for tracking paleoenvironmental changes associated with terrestrial plants. However, this application may be complicated by the possible contribution of long-chain n-alkanes from non-emergent aquatic plants. To explore this issue, a sedimentary core spanning
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Hornblendites as a record of differentiation, metasomatism and magma fertility in arc crust Chem. Geol. (IF 3.9) Pub Date : 2024-02-04 Ren-Zhi Zhu, Daniel J. Smith, Fangyue Wang, Jiang-Feng Qin, Chao Zhang, Shaowei Zhao, Min Liu, Fangyi Zhang, Yu Zhu, Shao-Cong Lai
The fractionation of hornblende is a common phenomenon in arc magmas, and gives rise to a number of notable geochemical characteristics. However, it is often cryptic, with limited direct petrographic evidence for the fractionation, or even presence of amphibole in volcanic suites. Newly identified hornblendites in the SE Tibet represent direct evidence for hornblende fractionation in the Gangdese arc
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Olivine formation processes and fluid pathways in subducted serpentinites revealed by in-situ oxygen isotope analysis (Zermatt-Saas, Switzerland) Chem. Geol. (IF 3.9) Pub Date : 2024-02-03 Michelle Ulrich, Daniela Rubatto, Jörg Hermann, Thorsten A. Markmann, Anne-Sophie Bouvier, Etienne Deloule
Dehydration of serpentinites plays a crucial role in mass transfer into the Earth's interior by releasing aqueous fluids and forming new minerals. These minerals, such as metamorphic olivine, can serve as tracers of fluid-related processes. High-pressure (HP) antigorite, metamorphic olivine, and coexisting magnetite in serpentinites from a continuous, km-scale outcrop within the Zermatt-Saas HP ophiolite
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Effect of phosphate on the sorption and fractionation of rare earth ions on kaolinite surface and its geochemical significance Chem. Geol. (IF 3.9) Pub Date : 2024-02-03 Jingwen Zhou, Xiaoliang Liang, Wenbin Yu, Xiaoju Lin, Puqiu Wu, Yanhong Jiang, Deyin Huang
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Biotic-abiotic mingle in rock varnish formation: A new perspective Chem. Geol. (IF 3.9) Pub Date : 2024-01-28 Amritpal Singh Chaddha, Anupam Sharma, Narendra Kumar Singh, Amreen Shamsad, Monisha Banerjee
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Spatial variation of dissolved copper isotope systematics in the Changjiang (Yangtze) River: Response to weathering processes and anthropogenic impacts Chem. Geol. (IF 3.9) Pub Date : 2024-02-02 Ana Cristina Vasquez, Zhiwei He, Junjie Guo, Shouye Yang
The stable isotopes of copper (Cu) in rivers and oceans are receiving increasing interest in their potential to trace Cu biogeochemical cycling and fingerprint Cu sources. Nonetheless, the continental sources and processes that control the Cu flux and isotope composition in large rivers, the main source of Cu to the ocean, remain to be fully understood. Here we present a comprehensive study of Cu and
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Trace element discrimination diagrams to identify igneous apatite from I-, S- and A-type granites and mafic intrusions: Implications for provenance studies and mineral exploration Chem. Geol. (IF 3.9) Pub Date : 2024-02-01 Marie A. Kieffer, Sarah A.S. Dare, Marylou Gendron
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Sources and implications of hydroxylated isoprenoid GDGTs on the northwest shelf of Australia through the Pliocene-Pleistocene era Chem. Geol. (IF 3.9) Pub Date : 2024-02-01 Yuxin He, Qingfeng Zhao, Huanye Wang
Hydroxylated glycerol dialkyl glycerol tetraethers (OH-GDGTs) have been recently recognized as alternative biomarkers for sea surface temperature (SST) estimations in oceanic environments. Yet, it is still unclear whether OH-GDGTs are applicable on the northwest shelf of Australia. Here we present results of OH-GDGTs from sedimentary cores at IODP Site U1461 covering the Pliocene-Pleistocene period
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Effects of phosphate on REY adsorption by goethite: Insights into REY enrichment and release in marine iron oxyhydroxides during early diagenesis Chem. Geol. (IF 3.9) Pub Date : 2024-02-01 Yongjia Liang, Xiaoming Sun, Dengfeng Li, Caroline L. Peacock, Yu Fu
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Fe(III) oxyhydroxides mediated electron transfer from thiols to O2 for hydroxyl radical production Chem. Geol. (IF 3.9) Pub Date : 2024-01-26 Peng Zhang, Wanyun Zhang, Hao Yu, Rong Chen, Yiran Liu, Yingxiao Tian, Songhu Yuan
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A new experimental monazite-xenotime thermometer: Application to metamorphic environments Chem. Geol. (IF 3.9) Pub Date : 2024-01-24 Wriju Chowdhury, Dustin Trail
Monazite and xenotime are common metamorphic phases that may be reliably U/Th-Pb dated to obtain absolute ages. The utility of these minerals is significantly enhanced if a crystallization thermometer can be developed and applied to better establish the temperature-time (T-t) paths of crustal terranes. Here we report experiments in which we have modeled the T-dependent Rare Earth element (REE) cationic
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Interaction between mantle plume and subduction-modified lithospheric mantle: Geochemical evidence from the picritic lavas from the Emeishan large igneous province Chem. Geol. (IF 3.9) Pub Date : 2024-01-29 Song-Yue Yu, Xie-Yan Song, Lie-Meng Chen
Continental flood basalts typically exhibit large variations in their chemical and isotopic compositions, which are significantly different from those of oceanic basalts. However, the origin of these geochemical heterogeneities remains unclear. Here, new Hf-Mg-Sr-Nd isotope and trace element data for the picritic lavas from the Emeishan large igneous province are used to constrain primary magma compositions
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Constraining uncertainty in boron isotope systematics using a Bayesian inversion engine reveals contrasting parameter sensitivities Chem. Geol. (IF 3.9) Pub Date : 2024-01-28 Aled D. Evans, Gavin L. Foster, Damon A.H. Teagle
Physical parameters within boron isotope systematics form a complex interplay that determine the boron isotopic composition of rocks, minerals, and fluids, but to date, providing constraints on uncertainty within boron equilibrium isotope modelling remains elusive. This underlying uncertainty limits the potency of boron isotopes as a tool for detecting fluid-rock exchange. A new equilibrium boron mineral-fluid
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Multi-isotope (Pb, Sb) approach to trace metallic contaminant sources at a historical mining and metallurgical site Chem. Geol. (IF 3.9) Pub Date : 2024-01-26 Floriane Guillevic, Magali Rossi, Eléonore Resongles, Rémi Freydier, Colin Ferrari, Cécile Quantin, Gaël Monvoisin, Jérôme Poulenard, Fabien Arnaud
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The influence of montmorillonite on the mineralogical and magnetic changes in magnetite and maghemite during microbial iron reduction Chem. Geol. (IF 3.9) Pub Date : 2024-01-23 Yating Yin, Jianan Liu, Shanshan Yang, Pengcong Wang, Zongmin Zhu, Hongmei Wang, Deng Liu
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Geochemistry of iron and trace metals in seep carbonates of the middle Okinawa Trough impacted by hydrothermal plumes Chem. Geol. (IF 3.9) Pub Date : 2024-01-23 Shuang-Shuang Qin, Mao-Xu Zhu, Tie Li, Xilin Zhang, Cuiling Xu, Hong Cao, Wei Geng, Bin Zhai, Ye Chen, Shixing Li, Zhilei Sun
Geochemistry of iron and trace metals in seep carbonates and its dependence on anaerobic oxidation of methane (AOM)-driven diagenesis in cold seeps are not well documented. Here we characterize geochemistry of Fe and trace metals in carbonate nodules collected at an active cold seep in the middle Okinawa Trough (OT) impacted by hydrothermal plumes. The carbonate nodules in the studied core are dominated
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Trace element systematics of magnetite from the Starra iron oxide‑copper gold deposits reveals early fluid conditions characteristic for Cu mineralization Chem. Geol. (IF 3.9) Pub Date : 2024-01-28 Max Hohl, Jeffrey A. Steadman, Jonathan Cloutier, Shaun L.L. Barker, Ivan Belousov, Karsten Goemann, David R. Cooke
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Neodymium and strontium isotopes track the origin of parent brines of primary gypsum deposits (Miocene, Fore-Carpathian Basin) Chem. Geol. (IF 3.9) Pub Date : 2024-01-28 Jolanta Dopieralska, Zdzislaw Belka, Mateusz Zieliński, Marcin Górka, Andriy Poberezhskyy, Oksana Stupka, Aleksandra Walczak, Anna Wysocka
Neodymium (Nd) isotopes constitute a versatile tracer frequently used in oceanography to identify water masses and track their circulation, both in the modern and ancient oceans and seas. In this research, for the first time, primary marine gypsum is being used as a new archive preserving Nd isotope signatures of past seawater and brines in very shallow-water settings. Nd isotope signatures (εNd values)
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Alpine stacking of two Variscan granite blocks recognised from mineral stabilities, age and structural data (Western Carpathians) Chem. Geol. (IF 3.9) Pub Date : 2024-01-26 Igor Broska, Igor Petrík, Keewook Yi, Jarosław Majka, Christopher J. Barnes, Rastislav Vojtko, Ján Madarás, Sergii Kurylo, Michal Kubiš
This study presents petrological, geochemical, geochronological and structural data that serve to identify two different Alpine tectonic units formed from the Variscan-aged Tribeč-Zobor granitic rocks. The proposed model for juxtaposition of two granite blocks in the Tribeč-Zobor basement during the Alpine orogeny is based on the degree of granite alteration, particularly related to differences in
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Roles of changes in land weathering intensity in the Nd cycle of the South China Sea during the past 30 kyr as inferred from neodymium isotopic composition in foraminifera Chem. Geol. (IF 3.9) Pub Date : 2024-01-20 Yi Huang, Christophe Colin, Zhifei Liu, Bertaz Joffrey, Arnaud Dapoigny, Eric Douville, Zhaojie Yu, Andrew Tien-Shun Lin
Neodymium isotopic compositions (εNd) in the marginal sea is influenced by the ocean circulations as well as the lithogenic input from continents, but their relative contributions and the impact of detrital sediments are not well constrained. In this study, Nd isotopic compositions of mixed planktonic foraminifera species and carbonate-free fraction of sediment from two cores collected at 1250–1350 m
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Magnesite everywhere: Formation of carbonates in the alkaline lakes and playas of the Cariboo Plateau, British Columbia, Canada Chem. Geol. (IF 3.9) Pub Date : 2024-01-21 Maija J. Raudsepp, Sasha Wilson, Nina Zeyen, Maria L. Arizaleta, Ian M. Power
The Cariboo Plateau in central British Columbia, Canada, hosts the largest aerial extent of low temperature lacustrine magnesite in the world. Magnesite was the most abundant carbonate mineral in 21 of 33 sampled alkaline lakes and 20 of 22 sampled playas. Calcite, hydromagnesite and very high magnesium calcite (VHMC, also called disordered dolomite) were also found in closed basin alkaline lakes on