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Impact of leaching process for ion-adsorption rare earth ore on the characteristics of topsoil and the absorption of rare earth by Dicranopteris pedata Biogeochemistry (IF 3.9) Pub Date : 2024-12-19 Haiyan Wang, Shujie Meng, Wenzhi Zhou, Guofu Wang, Zhibiao Chen, Zuliang Chen
Rare earth elements (REE) are important resources, but REE in the environment are also deemed to be a new class of pollutant. Phytoremediation, using the hyperaccumulator Dicranopteris pedata, offers a promising approach for reclaiming and recycling REE from mining tailings. However, how in situ leaching affects the topsoil characteristics of mining areas and the absorption of REE by D. pedata remains
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Soil CO2 efflux response to two decades of altered carbon inputs in a temperate coniferous forest Biogeochemistry (IF 3.9) Pub Date : 2024-12-18 Hayley Peter-Contesse, Aron Boettcher, Kate Lajtha
Global soils play a critical role in carbon (C) cycling and storage, and even minor disturbances to soil C flux can cause CO2 release to the atmosphere, exacerbating the greenhouse effect. This study investigates the long-term effects of forest detrital manipulation on soil CO2 efflux at a temperate forest site in Oregon’s western Cascade Mountains. We assessed the variation in seasonal and diurnal
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Black spruce boreal forest soil solution inorganic nitrogen is highly resilient to 20 years of elevated nitrogen deposition Biogeochemistry (IF 3.9) Pub Date : 2024-12-19 Daniel Houle, Marie Renaudin, Jean-David Moore, Louis Duchesne
Soil solution is the liquid phase of soil containing nutrients that are essential for vegetation’s health and growth. As such, soil solution chemistry is directly related to nutrient cycling and productivity in forest ecosystems. However, the long-term impacts of elevated N deposition on boreal forest soil solution composition remain uncertain. In this study, we investigate the effects of two decades
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Chemical determination of silica in seagrass leaves reveals two operational silica pools in Zostera marina Biogeochemistry (IF 3.9) Pub Date : 2024-12-19 Justine Roth, Morgane Gallinari, Jonas Schoelynck, Gema Hernán, Julia Máñez-Crespo, Aurora M. Ricart, María López-Acosta
Silicon is a major driver of global primary productivity and CO2 sequestration, and is a beneficial element for the growth and environmental stress mitigation of many terrestrial and aquatic plants. However, only a few studies have examined the occurrence of silicon in seagrasses, and its function within seagrass ecosystems and the role of seagrasses in silicon cycling remain largely unexplored. This
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The role of potassium in lode gold mineralization: insights from ab initio molecular dynamics and geochemical modeling Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-17 Gao-Hua Fan, Jian-Wei Li, Yuan Mei, Si-Yu Hu, Ri-Chen Zhong, Chang Yu, Xiao-Dong Deng, Hao Cui, Wen-Sheng Gao
Potassium ions (K+) are abundant in ore fluids of lode gold deposits, largely illustrated by pervasive potassic alteration and commonly expressed as K-feldspar and muscovite on both sides of individual gold lodes. However, their potential roles in gold mineralization remain elusive. Here, we present results from ab initio molecular dynamics simulation and geochemical modeling to address this question
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Immobilization of Sb(V) by secondary Fe (oxyhydr)oxides during Fe(II) oxygenation: Insights into Sb(V) incorporation and Fe(II) mineralization mechanisms Chem. Geol. (IF 3.6) Pub Date : 2024-12-16 Yiqing Wang, Mengchang He, Chunye Lin, Wei Ouyang, Xitao Liu
Abiotic Fe(II) oxygenation to form secondary Fe (oxyhydr)oxides commonly occurs in natural environments and critically affects the mobility and fate of metalloids such as antimony (Sb). However, the Sb(V) immobilization process and mechanism during Fe(II) oxygenation are not well understood, and the interactions between Sb(V) and formed Fe (oxyhydr)oxides need further study. This study comprehensively
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Rhenium residency in molybdenite, compressional textures and relationship to polytypism Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-13 Mao Tan, Yiping Yang, Xiao-Wen Huang, Jiaxin Xi, Nuo Li, Yu-Miao Meng, Liang Qi
Molybdenite has been established as a robust mineral for Re-Os isotope dating. However, higher-precision Re-Os molybdenite dating is necessary to accurately determine the absolute timing of metal mineralization and duration of ore-forming hydrothermal systems. To improve the precision and accuracy of molybdenite Re-Os dating, molybdenite from the Longmendian deposit—with its old age, heterogeneous
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Mercury evidence for volcanism driving environmental changes during the protracted Late Ordovician mass extinction and early Silurian recovery Chem. Geol. (IF 3.6) Pub Date : 2024-12-13 Yanfang Li, Hui Tian, Tongwei Zhang, Baojian Shen, Deyong Shao
Volcanism has been proposed as the trigger for the environmental perturbations and associated mass extinction during the Ordovician–Silurian (OS) transition. However, the timing, duration, and intensity of volcanic eruptions during this critical period and their relationships to environmental perturbations and biotic changes remain unresolved. In this study, we use mercury (Hg) concentrations and isotopes
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Hydrothermal origin of platinum-group minerals during serpentinization of the podiform chromitites from the Kızıldağ ophiolite in southern Türkiye Chem. Geol. (IF 3.6) Pub Date : 2024-12-13 Chen Chen, Christina Yan Wang, Saihong Yang, İbrahim Uysal
Platinum-group minerals (PGMs) in podiform chromitites usually occur in the interior and/or edge of chromite. However, the origin of PGMs in podiform chromitites has long been a matter of debate. Here we examined sub-micro to nanoscale textural features, morphologies, and compositions of PGMs from the disseminated, banded, massive and nodular chromitites in the Kızıldağ ophiolite in southern Türkiye
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The solubility of La hydroxide and stability of La3+ and La hydroxyl complexes at acidic to mildly acidic pH from 25 to 250 °C Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-10 Kevin Padilla, Alexander P. Gysi
The mobility of rare earth elements (REE) in natural hydrothermal systems can be assessed using geochemical modeling, which requires reliable thermodynamic data of relevant aqueous species. In this study, we evaluate the controls of pH and temperature on La speciation and the role of hydroxyl complexes in REE transport at hydrothermal conditions. Batch-type hydrothermal solubility experiments were
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Fe-dependent structural evolution of peralkaline soda aluminosilicate glasses: Iron speciation vs. glass transition Chem. Geol. (IF 3.6) Pub Date : 2024-12-10 Michele Cassetta, Emanuele De Bona, Alessia Sambugaro, Francesco Enrichi, Nicola Daldosso, Beatrice Giannetta, Claudio Zaccone, Mattia Biesuz, Vincenzo M. Sglavo, Renat Almeev, Luca Nodari, Daniele Giordano, Gino Mariotto
The incorporation of iron into peralkaline silicate glasses significantly impacts their structural and thermal properties. Here we investigate how addition of iron influences the network connectivity (short- and medium-range order) and glass transition temperature (Tg) with particular regard to the iron speciation and the Fe2+ and Fe3+ coordination state. We also found a sort of tipping point in iron
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Pressure sensor based on the Raman shift of the 128-cm−1 band of quartz for pressure measurements in hydrothermal diamond-anvil cells Chem. Geol. (IF 3.6) Pub Date : 2024-12-10 Jiankang Li, I-Ming Chou, Xian Wang, Yongchao Liu, Ziheng Han, Jie Gao
To interpret data collected from high-pressure (P)–temperature (T) experiments simulating geological processes, pressure information during these experiments is crucial. Traditionally, the Raman shifts of the quartz 464-cm−1 band are commonly used as a hydrostatic-pressure calibrant in such experiments, particularly in those performed using hydrothermal diamond-anvil cells (HDACs). In this study, we
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Evaluating the role of tectonic setting in new continental crust formation by U/Pb ratios Chem. Geol. (IF 3.6) Pub Date : 2024-12-10 Xian Chen, Zhengzhe Fan
The role of tectonic setting in new continental crust formation remains enigmatic. A key to solve this issue is to determine which tectonic setting(s) are involved in the generation of new continental crust through time. Modern mantle-derived magmas that formed in intracontinental extension settings (U/Pb = ∼0.28–0.37) and in subduction settings (U/Pb = ∼0.1–0.16) have distinct mean U/Pb ratios. When
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Redox conditions in a carbonatite-alkaline complex: Deciphering Fe- and S-XANES in melt inclusions with silicate‑carbonate immiscibility Chem. Geol. (IF 3.6) Pub Date : 2024-12-10 Céline Baudouin, Hugo Moreira, Charles Le Losq, Max Wilke, Fleurice Parat
Hanang is a volcano in the southern part of the east branch of the East African Rift (North Tanzania Divergence) and represents volcanism at the early stage of continental break-up. Hanang volcanism is characterized by CO2-alkaline-rich magmas and silicate‑carbonate immiscibility process at crustal level. This study describes microscale iron (Fe) and Sulfur (S) K-edge X-ray absorption near edge structure
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Terrestrial mercury anomalies across the Permian-Triassic transition in North China linked to volcanism Chem. Geol. (IF 3.6) Pub Date : 2024-12-09 Peixin Zhang, Minfang Yang, Jing Lu, Zhongfeng Jiang, Lei Wang, Yuanyuan Zhu, Wenjing Guo, Zejing Li, Zhibiao Shi, Pan Wang, Kai Zhou, Xiaotao Xu, Longyi Shao, Jason Hilton
The Permian-Triassic mass extinction (PTME) is the most severe biological crisis in Earth history and is closely linked to massive contemporaneous volcanism. However, there is currently limited evidence of Mercury (Hg) enrichment directly from volcanic sources in terrestrial strata, necessitating evidence from different regions and latitudes to confirm the relationship between volcanism and changes
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Prediction of organic geochemical parameters from inorganic geochemical data in the Cretaceous-Danian Moreno Formation, San Joaquin Basin, California Chem. Geol. (IF 3.6) Pub Date : 2024-12-09 Hunter C. Olson, Allegra Hosford Scheirer, Samantha R. Ritzer, Erik A. Sperling
Accurately reconstructing original Total Organic Carbon (TOC) in thermally mature rocks is essential for the correct application of geochemical proxies and understanding organic carbon burial through time. To reconstruct original TOC using empirical methods, it is vital to have an accurate estimate of the original Hydrogen Index (HI). The two most common methods are estimating original HI using kerogen
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Triple oxygen and hydrogen stable isotope composition of water in Murchison carbonaceous chondrite accessed by thermogravimetry-enabled laser spectroscopy Chem. Geol. (IF 3.6) Pub Date : 2024-12-09 Erik J. Oerter, Alexandre Garenne, Miguel Cisneros, George D. Cody, Michael Singleton, Conel M. O’D. Alexander
We have developed the capability to measure 17O/16O in H2O and OH− of hydrous minerals by a technique using thermogravimetric analysis coupled with isotope ratio infrared spectroscopy (TGA-IRIS) on a suite of liquid water standards, terrestrial mineral standards, multi-mineral synthetic mixtures of terrestrial samples, and Murchison carbonaceous chondrite. This 17O/16O analytical capability is combined
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Multistage formation and geochemical response of pipe-morphology cold seep carbonate in the Qiongdongnan Basin, northern South China Sea Chem. Geol. (IF 3.6) Pub Date : 2024-12-09 Jing Zhao, Xuewan Wu, Wei Zhang, Zhifeng Wan, Yifei Dong, Xi Xiao, Yang Wu, Xiaoyu Wu, Junxi Feng, Qianyong Liang
Cold seep carbonates are commonly used to record the nature of seepage, including fluid sources, diagenetic environments, and variations in seepage activity. However, the relationship between diagenetic environments and trace element enrichment in dynamic environments is poorly understood. Pipe-morphology cold seep carbonates form from outside to inside in methane seeps and record variations in elements
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n-Alkanes δ13C and salinity correlation in mangrove Aegiceras corniculatum leaves and surface sediments from Zhanjiang estuaries, China Chem. Geol. (IF 3.6) Pub Date : 2024-12-08 Guifang Cai, Zhao-Wen Zhan, Zhiguang Song, Yao-Ping Wang, Jia Xia, Ding He
Carbon isotope ratios (δ13C) in plant lipid biomarkers yield insights into historical climates by reflecting plant responses to environmental stressors. Previous research has established a correlation between increased salinity and elevated δ13C in Avicennia marina leaf wax n-alkanes, yet it remains unclear if these isotopic signatures are universally applicable across different species and regions
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Coupling stable isotope analyses and X-ray absorption spectroscopy to investigate the molecular mechanism of zinc sorption by calcite Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-07 Yiren Duan, Hongtao He, Wenchao Liu, Wenxian Gou, Zhao Wang, Peng Liu, Jing Zhang, Caroline L. Peacock, Wei Li
Calcite plays a pivotal role in regulating the mobility and fate of zinc (Zn) in natural environments. Despite its significance, the mechanism of Zn sorption on calcite surfaces, particularly the transitional dynamics from surface adsorption to precipitation, remains unclear. This research studied the sorption behavior of Zn on calcite across a wide range of reaction times, pH values, and Zn concentrations
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Source composition or melting effect: New evidence from Archean komatiites concerning the origin of low highly siderophile element abundances in Earth’s mantle Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-07 Xiaoyu Zhou, Ratul Banerjee, Laurie Reisberg, Sisir K. Mondal
Highly siderophile element (HSE) contents of komatiites have been widely used to estimate the HSE composition of Earth’s mantle. However, the interpretation of existing komatiite data is controversial, with some authors arguing that the Archean deep mantle komatiite source was impoverished in HSE due to slow admixture of a late accretion component, while others invoke a melting process that would allow
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Deciphering multiple episodes of partial melting, metasomatic and remelting processes in the Eastern Pyrenean orogenic mantle massif Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-07 Yujian Wang, Jingao Liu
Secular variations in the composition of the subcontinental lithospheric mantle (SCLM) are intimately controlled by multiple geological processes, including diverse melting mechanisms and complex metasomatic processes. We present comprehensive analyses of whole rock and mineral chemistry, along with Re-Os isotopic system of the Eastern Pyrenean orogenic mantle massifs, supported by quantitative modeling
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Cadmium isotope fractionation and neutron capture effects in lunar samples Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-07 W. Abouchami, F. Wombacher, S.J.G. Galer
Early pioneering studies of Apollo lunar soils revealed a geochemical dichotomy reflecting a dominance of mare and highland lithologies, with variable additions of Procellarum KREEP Terrane material. Here, we use the moderately volatile element cadmium to identify the sources and processes responsible for mass-dependent Cd stable isotope variations in the lunar regolith. In addition, capture of thermal
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Extreme rare earth element (REE) enrichment during weathering recorded in saprolites from South Carolina Chem. Geol. (IF 3.6) Pub Date : 2024-12-07 Utpalendu Haldar, Ramananda Chakrabarti, Roberta L. Rudnick
Rare earth elements (REE) and other trace element concentrations as well as 143Nd/144Nd and 87Sr/86Sr in saprolites developed on the Cayce metadiabase dike, South Carolina, document extreme REE mobilization during chemical weathering and enrichment of REE on clays. Saprolites display a bimodal distribution in their total REE concentrations (ΣREE) and light-REE (LREE)/heavy-REE (HREE) ratios. Shallower
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Molecular signatures of biomacromolecules at micron and submicron scales in Arctica islandica shells Chem. Geol. (IF 3.6) Pub Date : 2024-12-07 Oluwatoosin B.A. Agbaje, Qian Huang, Michiel Op De Beeck, Per L. Ambus, Lisbeth G. Thygesen, Bernd R. Schöne, Karina K. Sand
Arctica islandica (Linnaeus, 1767) is a bivalve mollusk with a lifespan of up to 500 years. Its shell is a complex inorganic-organic nanocomposite, which is still not fully characterized. Here, we used Optical Photothermal Infrared (O-PTIR) microspectroscopy to characterize its organic phase, i.e. the hydrophobic insoluble extracts of both modern and fossil A. islandica shells. We compared the spectra
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A comprehensive and consistent mineral dissolution rate database: Part III: Non-silicate minerals including carbonate, sulfate, phosphate, halide, and oxy-hydroxide minerals Chem. Geol. (IF 3.6) Pub Date : 2024-12-06 Eric H. Oelkers, Mouadh Addassi
This paper describes the creation of a consistent database of the far-from-equilibrium dissolution rates in aqueous fluids of the major non-silicate minerals including carbonates, sulfates, phosphates, oxides and hydroxides. This work, based on the regression of available dissolution rate data normalized to their BET surface area as a function of pH and temperature, was performed using equations described
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Radiation-enhanced fluid diffusion and alteration around uraniferous inclusions in Cenomanian resinite from North Bohemia Chem. Geol. (IF 3.6) Pub Date : 2024-12-06 Vladimír Strunga, Vladimír Havránek, Jan Lorinčík, Kristína Sihelská, Pavel Krist, Martina Havelcová, Bohuslava Čejková, Jiří Mizera
Advanced analytical methods including SEM/EDX and μ-PIXE/RBS microanalyses were used to investigate chemical alterations around uraniferous inclusions in a Cenomanian fossil resin (resinite). Studied alterations related to several types of discontinuities in resinite matrix are a model example of the phase interface between solid polymeric hydrocarbon and aqueous fluids exposed to long-term irradiation
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Surface acid alteration of juvenile Andean pyroclastic rocks: effect of glass composition on the development of surface fluoride-bearing minerals Chem. Geol. (IF 3.6) Pub Date : 2024-12-06 J.A. Vila, G.L. Bia, S. Bengió, C. Balbis, L. Borgnino
During eruption, sulphur dioxide gas interacts with glass shards, favouring the formation of sulphuric acid (H2SO4) aerosols and coatings enriched in hazardous elements such as fluorine (F). This study discusses the formation of F-bearing compounds during acidic weathering of Andean juvenile pyroclastic rock emitted from Puyehue and Lanín volcanoes and their potential to release F into aqueous reservoirs
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Association of tungsten with aluminosilicate mineral colloids and silicotungstates in soil porewaters: Insights into the unexpectedly high tungsten mobility in soil Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-05 Lei Lu, Jing Sun, Yu Dai, Yaoyu Zhou, Haojie Cui, Ming Lei, Huihui Du
As an emerging contaminant, tungsten (W) displays unexpectedly high mobility in soil despite its extremely low solubility, challenging current scientific understanding. This paradox underscores the limited knowledge regarding the specific W species responsible for its high mobility. In this study, a series of field and incubation experiments were conducted across multiple soil types to investigate
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Petrology of alkali gabbro from the Messum Crater, Namibia (Paranà-Etendeka Province) – Melting of metasomatized carbonated lithospheric mantle sources Chem. Geol. (IF 3.6) Pub Date : 2024-12-05 S. Jung, R.L. Romer, J.A. Pfänder
Foid gabbros (alkali gabbros) are late-stage intrusive rocks into the alkaline core of the Cretaceous Messum complex, an anorogenic ring complex belonging to the Etendeka Large Igneous Province in NW Namibia. The mineralogy of the alkali gabbros is characterized by primary olivine, clinopyroxene (Ti-augite), nepheline and plagioclase and late-stage or secondary brown Ti-amphibole and biotite plus magnetite
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Calcium isotopes support spatial redox gradients on the Tethys European margin across the Triassic-Jurassic boundary Chem. Geol. (IF 3.6) Pub Date : 2024-12-05 Ashley N. Prow-Fleischer, Zunli Lu, Clara L. Blättler, Tianchen He, Pulkit Singh, Preston Cosslett Kemeny, Jordan P. Todes, Alexandre Pohl, Tripti Bhattacharya, Bas van de Schootbrugge, Paul B. Wignall, Simona Todaro, Jonathan L. Payne
The end-Triassic mass extinction was among the most severe biotic crises of the Phanerozoic. It has been linked with the global expansion of marine anoxia, and the prolongation of these conditions within epeiric seas has been proposed as a cause for the suppression of biodiversity during the early Jurassic Hettangian Stage. Testing this interpretation is complicated by spatially heterogeneous patterns
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Rapid bioproductivity recovery following the Marinoan glaciation: Evidence from Sr-Cr-Cd isotopes and trace elements in the Morraria do Sul cap dolostone, Brazil Chem. Geol. (IF 3.6) Pub Date : 2024-12-05 Henrique Albuquerque Fernandes, Paulo César Boggiani, Jesper Allan Frederiksen, Marcelo Da Roz Campos, Vinicius Cardoso-Lucas, Bernardo Tavares Freitas, Robert Frei
Early Ediacaran cap dolostones are distinctive strata deposited directly above glaciogenic rocks from the Marinoan Glaciation (650–635 Ma), one of the most dramatic ice ages in Earth's history. These cap dolostones were rapidly deposited during global synchronous deglaciation, being a superb depositional window into the immediate glaciation aftermath and suitable for investigating the icehouse-hothouse
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Ca-Sr-Nd isotopic signatures of mid-ocean ridge basalts from the Central Indian Ridge and implications for recycled materials in the Indian Ocean mantle domain Chem. Geol. (IF 3.6) Pub Date : 2024-12-05 Hongli Zhu, Yujie Shan, Renqiang Liao, Lipeng Zhang, Jianghong Deng, Congying Li, Long Du, Zhaofeng Zhang, Weidong Sun
Mid-ocean ridge basalts (MORBs) from the Indian Ocean have been demonstrated to have more enriched radiogenic isotopic compositions than MORBs from the Pacific and Atlantic Oceans. However, the origin of such anomaly is still under debate. To better constrain the genesis of the isotopic anomaly observed in Indian MORBs, we present a systematic Ca-Sr-Nd isotopic study of a suite of MORBs from the Central
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Clumped isotope measurements reveal aerobic oxidation of methane below the Greenland ice sheet Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-12-04 Getachew Agmuas Adnew, Thomas Röckmann, Thomas Blunier, Christian Juncher Jørgensen, Sarah Elise Sapper, Carina van der Veen, Malavika Sivan, Maria Elena Popa, Jesper Riis Christiansen
Clumped isotopes of methane (CH4), specifically Δ13CH3D and Δ12CH2D2, provide additional information to constrain its sources and sink processes. These isotopes complement interpretations of CH4 provenance based on bulk isotopes. However, interpreting the origin of CH4 using isotopes becomes challenging when the isotopic signature is altered by post-generation processes. In this study, we measured
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Bimineralic calcite-aragonite rafts in the hypogeous lakes of Cova dets Ases (Mallorca): Controls on precipitation and polymorphism Chem. Geol. (IF 3.6) Pub Date : 2024-12-04 A. Entrena, L.F. Auqué, M.J. Gimeno, J.J. Fornós
Calcite-aragonite bimineralic rafts and related waters from hypogenic lakes in the coastal cave of “Cova dets Ases”, Mallorca, have been analyzed for mineralogy and geochemistry (including stable isotopes). The main objective has been the evaluation of the factors that control the chemical and mineralogical composition of the precipitates as they are another natural example of the classical problem
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Single quartz δ18O: A new frontier in detrital provenance analysis (Bengal Fan, IODP Expedition 354) Chem. Geol. (IF 3.6) Pub Date : 2024-12-03 Mara Limonta, Christian France-Lanord, Albert Galy, Andrey Gurenko, Nordine Bouden, Eduardo Garzanti
Quartz is the most abundant mineral in sediments and sedimentary rocks but efforts to reliably identify its provenance have been only partially fruitful so far. Even advanced methods such as cathodo-luminescence, Raman spectroscopy, synchrotron X-ray absorption spectroscopy, and laser ablation spectrometry have led to limited success. This article demonstrates how the δ18O of detrital quartz provides
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Non-conservative behaviour of molybdenum in the Ganga (Hooghly) River estuary, India: Role of solute-particle interaction and sediment diagenesis Chem. Geol. (IF 3.6) Pub Date : 2024-12-03 Rakesh K. Tiwari, Tarun K. Dalai, Rupak Samadder, Waliur Rahaman, Sunil K. Singh
This study is focussed on understanding of molybdenum (Mo) cycling in the mesotidal to macrotidal estuary of the Ganga (Hooghly) River in India. Our investigation encompasses the composition of water and suspended particulate matter (SPM) samples collected in three separate periods (pre-monsoon: PrM, monsoon: M and post-monsoon: PoM) over two consecutive years, surface sediments, exchangeable phases
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Mechanism of cadmium (Cd) enrichment in the soil of karst areas with high geochemical background in Southwest China Chem. Geol. (IF 3.6) Pub Date : 2024-12-03 Bo Li, Kun Lin, Xu Liu, Xudong Ma, Xuezhen Li, Zhiliang Wu, Cheng Li, Tao Yu, Tiansheng Wu, Zhongfang Yang
Karst areas are formed from the dissolution of carbonate rocks and are present worldwide. The soil found in such areas is enriched in heavy metals, such as cadmium (Cd), lead (Pb) and Arsenic (As), and has geological high-background characteristics. However, this enrichment is anomalous depending on the type of bedrock, and the mechanism of enrichment has not yet been comprehensively elucidated. To
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Unraveling the link between worldwide adakite-like rocks and porphyry Cu deposits Chem. Geol. (IF 3.6) Pub Date : 2024-12-03 Chao Wu, Guoxiong Chen, Huayong Chen
Adakite-like rocks, as an important recorder of magmatic evolution in mantle and crust, are closely associated with major porphyry Cu deposits. However, the underlying mechanism connecting these associations remains insufficiently elucidated. This study compiles ca. 7000 whole-rock geochemical data from Phanerozoic adakite-like rock samples and from ore-forming porphyries in porphyry Cu deposits. Machine
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Using δ65Cu and δ34S to determine the fate of copper in stream waters draining porphyry mineralization: Implications for exploration targeting Chem. Geol. (IF 3.6) Pub Date : 2024-12-02 James A. Kidder, Christopher E. Beckett-Brown, Alexandre Voinot, Zhaoping Yang, Pierre Pelchat, Duane C. Petts, Matthew Polivchuk, John B. Chapman, Scott Casselman, Matthew I. Leybourne
The fate of metals, such as Cu, in stream waters draining porphyry mineralization is commonly controlled by several natural processes such as sorption, microbial processes, and ligand availability. Isotopes of Cu offer a novel approach to understanding these processes and determining metal sources within complicated mineralogical systems. Drainages at the Casino Cu-Au-Mo porphyry deposit, Yukon, Canada
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Iron isotope fractionation in highly evolved magmas results from ilmenite crystallization Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-30 Fengli Shao, Yaoling Niu, Haiquan Wei, Yu Zhang, Guodong Wang
Globally, granites and rhyolites with SiO2 > 70 wt% show large Fe isotope variation (δ56Fe = −0.05 to +0.65 ‰) relative to less silicic igneous rocks in δ56Fe vs. SiO2 space. The upper bound of the data tends to show δ56Fe increase with increasing SiO2. Granitic magma differentiation can be invoked to explain magma compositional variation, including Fe isotope variation, but clearly cannot explain
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Submicron-sized anhydrous crystalline silicates and their relation to amorphous silicate in the matrix of Acfer 094 Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-30 Hugues Leroux, Pierre-Marie Zanetta, Corentin Le Guillou, Maya Marinova
The study of pristine chondrites provides insight into nebular processes that occurred prior to the accretion of small-sized parent bodies. The interchondrule matrix of the primitive chondrite Acfer 094 is characterized by the presence of submicron-sized anhydrous crystalline aggregates embedded in a silicate groundmass that is mostly amorphous. Transmission electron microscopy (TEM) and energy-dispersive
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Grassland woody encroachment alters subsurface mineral weathering and groundwater composition in a carbonate system Chem. Geol. (IF 3.6) Pub Date : 2024-11-30 Christa Anhold, Camden Hatley, Eresay Alcantar-Velasquez, Rachel M. Keen, Kayalvizhi Sadayappan, Karla M. Jarecke, Pamela L. Sullivan, Jesse B. Nippert, Li Li, G.L. Macpherson, Matthew F. Kirk
Displacement of grasses by woody plants (woody encroachment) is occurring in grasslands worldwide. Previous studies indicate that encroachment can alter subsurface carbon dioxide (CO2) concentrations and mineral weathering, though these impacts are still poorly understood. To address this knowledge gap, we sampled groundwater and stream water every three weeks during the 2022 water year from two watersheds
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Preservation of biosignatures in Neoproterozoic phosphorites metamorphosed at temperatures >450 °C Chem. Geol. (IF 3.6) Pub Date : 2024-11-30 Kenan Cao, Zhenbing She, Dominic Papineau, Jingbo Nan, Chao Chen, Reza Deevsalar, Ayetullah Tunc, Qunfeng Xiao, Kang-Jun Huang, Yuanming Pan
There is still much controversy over whether apatite and graphite can be used as fingerprint mineral assemblages to preserve biosignatures in ancient sedimentary rocks that experienced medium- to high-grade metamorphism. Herein, we present a comprehensive analysis of graphite and associated phases from meta-phosphorites of the Huangmailing Formation in the South Dabie Orogen to assess possible preservation
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Re-Os isotopic evidence for ancient melt depletion in refertilized Neo-Tethyan suboceanic mantle domain Chem. Geol. (IF 3.6) Pub Date : 2024-11-30 Yang Xu, Chuan-Zhou Liu, Chang Zhang, Tong Liu
Ancient mantle domains with unradiogenic Os isotopes have been well documented in the Yarlung-Tsangpo ophiolites (YTO), southern Tibet. Nonetheless, previous Os isotope studies have yielded relatively young Re-depletion model (TRD) ages of <1.0 Ga for mantle peridotites of the Zedong ophiolite in the eastern segment of the YTO. In this study, a comprehensive petrological and geochemical study has been
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Dissolution and solubility of the calcium-nickel carbonate solid solutions [(Ca1−xNix)CO3] at 25 °C Geochem. Trans. (IF 0.9) Pub Date : 2024-11-29 Chengyou Ma, Xiaoke Nong, Fan Xu, Zongqiang Zhu, Peijie Nong, Fei Luo, Shen Tang, Lihao Zhang, Zhiqiang Kang, Yinian Zhu
A series of the calcium-nickel carbonate solid solutions [(Ca1−xNix)CO3] were synthesized and their dissolution in N2-degassed water (NDW) and CO2-saturated water (CSW) at 25 °C was experimentally investigated. During dissolution of the synthetic solids (Ni-bearing calcite, amorphous Ca-bearing NiCO3 and their mixtures), the Ni-calcite and the Ca-NiCO3 dissolved first followed by the formation of the
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Investigating pressure effects of Ti and Zr partitioning into zircon, quartz, and rutile at crustal temperatures Chem. Geol. (IF 3.6) Pub Date : 2024-11-29 Heather M. Kirkpatrick, Dustin Trail, T. Mark Harrison, Elizabeth A. Bell
The dependency of Ti partitioning between quartz and zircon on the activity of TiO2 and Zr partitioning between zircon and rutile on the activity of ZrO2 suggest that an intercalibration among the three minerals (i.e., concentration information from all three phases in the same experiment) could reduce propagated errors when using multiple systems simultaneously. Experiments were undertaken to assess
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The fluid/melt partitioning of chlorine, bromine and iodine in felsic magmas and the utility of halogen ratios to track the devolatilization and fluid fluxing of magma reservoirs Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-27 Mara Miranda, Zoltán Zajacz, Alexandra Tsay, Anne-Sophie Bouvier
The release of fluids from magmas at crustal depths is an essential process for the formation of magmatic-hydrothermal ore deposits. However, assessing the extent of volatile loss by magma degassing or volatile gain by fluid fluxing from deeper magmas remains challenging. To develop a new tool to quantitatively track these processes, we experimentally determined the partition coefficients of Cl, Br
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Volcanic-intrusive connections and crystal-melt segregation in the Dulan tilted crustal section: Insights from accessory mineral evolution Chem. Geol. (IF 3.6) Pub Date : 2024-11-27 Bin Liu, Luan Wu, Chang-Qian Ma, Meng-Yu Zhang, Zhen-Hua Xue, Yang Sun, Shi-Ze Li
The volcanic-intrusive connection is critical for understanding the formation of transcrustal magma systems and the mechanisms driving magma eruption. Yet, the genetic links between abyssal intrusive rocks and acidic volcanic rocks remain poorly understood. Here, we present new data from the Dulan volcanic-intrusive complex, a tilted section of the East Kunlun orogenic belt, integrating zircon UPb
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Boron diffusion, related isotope fractionation and the structural role of B in pegmatite forming melts Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-26 Christian R. Singer, Harald Behrens, Ingo Horn, Michael Fechtelkord, Stefan Weyer
In this study, we experimentally investigate the diffusion of B in flux-rich (1.7 % Li2O, 2.5 % B2O3, 2.7 % P2O5 and 3.5 % F) pegmatite forming melts in order to assess the transport mechanisms of B in rare-element pegmatite deposits. Glasses were synthesized with either different B isotope compositions or with different B concentrations (up to 2.45 wt% B2O3). In order to explore the effect of water
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The effect of carbonate chemistry on trace element incorporation in high-Mg calcitic foraminifera Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-26 Hagar Hauzer, David Evans, Wolfgang Müller, Yair Rosenthal, Jonathan Erez
The sodium-to-calcium ratio (Na/Ca) of biogenic CaCO3 has recently been introduced as a proxy for past seawater Ca2+ concentrations ([Ca2+sw]) as demonstrated by a positive correlation between seawater and shell Na/Ca with a minor influence of salinity. In the present study, we investigate the effect of carbonate chemistry on the Na/Ca proxy by conducting a set of experiments in which pH and the concentration
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The geochronology and cooling history of type 7 chondrites: Insights into the early impact events on chondritic parent body Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-26 Ye Li, Yuting Wang, Haoxuan Jiang, Jia Liu, Liping Qin, Qiu-Li Li, Yu Liu, Zhenfei Wang, Weibiao Hsu
Type 7 chondrites, which record a higher degree of heating process than typical type 3 to type 6 chondrites, are characterized with textures and petrography of partial melting. Understanding the timing and cooling history of incipient melting event for type 7 chondrites could provide insights into the complex thermal process of the early solar system. Here, we studied two chondrites NWA 12272 and NWA
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Copper isotopic evidence of microbial gold fixation in the Mesoarchean Witwatersrand Basin Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-26 Ryan Mathur, Linda Godfrey, Hartwig E. Frimmel, Nathan Yee, David Mossman, Peter Baran, Victor A. Valencia
A comparison of the copper isotope composition of sedimentary rock strata spanning in age across the Great Oxidation Event (GOE) and that of pyrite, carbon, and native gold from the Mesoarchean Witwatersrand Basin reveal that an oxidative gradient triggered gold precipitation on biologic material, now present in the form of gold-rich carbon seams in the latter. Oxidative redox reactions are known to
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Fe-isotopic evidence for hydrothermal reworking as a mechanism to form high-grade Fe-Ti-V oxide ores in layered intrusions Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-26 Dachuan Wang, Tong Hou, Roman Botcharnikov, Stefan Weyer, Sarah-Lynn Haselbach, Zhaochong Zhang, Meng Wang, Ingo Horn, Francois Holtz
The genesis of high-grade Fe-Ti-V oxide ores (up to >90 vol%) in layered intrusions remains highly debated. Here, on example of Hongge layered intrusion in China, we show that hydrothermal dissolution and precipitation of Fe-Ti-V oxides played a critical role in forming high-grade massive ore deposits as demonstrated by textural-compositional evidence and in-situ iron isotope data (δ56Fe), analyzed
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Application of Ni, Cu and Fe isotopes as indicators of ore genesis - New insights from the epigenetic-hydrothermal Rajapalot Au[sbnd]Co prospect, Finnish Lapland Chem. Geol. (IF 3.6) Pub Date : 2024-11-26 J. Tepsell, Y. Lahaye, F. Molnár, O.T. Rämö, N. Cook
Application of stable transition metal isotopes as indicators of ore genesis is becoming more popular, yet the fractionation mechanisms and isotopic distribution in these unconventional systems remain poorly understood. In this study, we present an analysis of sulphide Ni, Cu and Fe isotopes measured from solution using multicollector ICP-MS. The data were collected from the dominant sulphide phases
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Kinetic Mg[sbnd]Fe isotope fractionation in natural basalts during melt-peridotite interaction Chem. Geol. (IF 3.6) Pub Date : 2024-11-26 Gang Zeng, Xiao-Jun Wang, Xiao-Yu Zhang, Yuan Zhong, Jin-Hua Shi, Xun Yu, Lie-Wen Xie, Li-Hui Chen
Although Mg and Fe isotopes are frequently used to trace the source heterogeneity of basalts (e.g., recycled carbonated materials or eclogite in the mantle), they can also be fractionated by geological processes during magma migration from the source to the surface. Recently, the light Mg and heavy Fe isotopic compositions observed in high-Ti lunar basalts have been attributed to the kinetic fractionation
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Apatite as an indicator of tectono-magmatic evolution of silica-undersaturated to silica-oversaturated rocks on the NW Indian Plate margin Chem. Geol. (IF 3.6) Pub Date : 2024-11-25 Musa Khan, Huan Li, Thomas J. Algeo, Asad Khan, Adnan Khan, Yiming Xie
Permo-Carboniferous intrusive rocks situated on the NW boundary of the Indian Plate between the Main Mantle Thrust (MMT) and Main Boundary Thrust (MBT) have tremendous potential for enhancing our knowledge of regional tectono-magmatic activity in Pakistan, yet these units have received only limited investigation to date. Here, we examine the petrology, apatite geochemistry and Sr-Nd isotopes, and geochronology
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The partitioning of chalcophile and siderophile elements (CSEs) between sulfide liquid and carbonated melt Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-24 Shuo Xue, Yuan Li
Carbonated melts play a significant role in mobilizing lithophile and volatile elements in the Earth’s mantle and mantle metasomatism. However, there has been limited investigation into their potential for mobilizing chalcophile and siderophile elements(CSEs). In this study, we experimentally determine the sulfide liquid–carbonated melt partition coefficients of CSEs (DCSESul/C_melt) for a range of
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Secular evolution of continental crust of the North China Craton constrained by U-Pb and Lu-Hf-O/Sm-Nd isotopic analyses of detrital zircon and monazite in river sediments Chem. Geol. (IF 3.6) Pub Date : 2024-11-23 Guangyan Zhou, D. Graham Pearson, Yan Luo, Long Li, Christopher M. Fisher, Rui Li, Wei Wang, Yuanbao Wu
Robust detrital minerals from large rivers that sample large-scale continental areas represent important archives of continental crust evolution though time. Compared to the single proxy approach, integrating multiple isotope systems of multiple detrital minerals helps to gain a more comprehensive understanding of crustal growth and evolution. This novel method has so far only been applied to single-sample
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Climate controls on speleothem initial 234U/238U ratios in midlatitude settings over two glacial cycles Geochim. Cosmochim. Acta (IF 4.5) Pub Date : 2024-11-22 Carlos Pérez-Mejías, Jian Wang, Youfeng Ning, Ana Moreno, Antonio Delgado-Huertas, R. Lawrence Edwards, Hai Cheng, Heather M. Stoll
Despite early hydrological studies of 234U/238U in groundwaters, their utilization as a paleoclimatic proxy in stalagmites has remained sporadic. This study explores uranium isotope ratios in 235 datings (230Th) from six stalagmites in Ejulve cave, northeastern Iberia, covering the last 260 ka. The observed 234U enrichment is attributed to selective leaching of 234U from damaged lattice sites, linked