-
The effects of water-flooding and wet-to-dry transition on phase transformation of schwertmannite chemically formed in constant pH condition Chem. Geol. (IF 3.9) Pub Date : 2024-04-16 Baoting Ding, Jianru Liang, Yan Dong, Mingjiang Zhang, Lixiang Zhou
Schwertmannite formed under constant pH maintained by alkali additives exhibits great arsenic (As) adsorption capacities and has been used to remediate As-contaminated soil. However, variable soil moisture contents probably induce the phase transformation of schwertmannite, consequently affecting the environmental fate of contaminants in the mineral. This study investigates the effects of extreme water
-
Geochemistry of metabasite in Mariana forearc serpentinite mudflows documents interactions between serpentinizing fluid and subducted seamount basalts Chem. Geol. (IF 3.9) Pub Date : 2024-04-09 Rui-Peng Zhao, Hong-Yan Li, Jeffrey G. Ryan, Xun Wei, Sheng-Xiong Yang, Yi-Gang Xu
Understanding the chemical composition of materials within the subducting slab is crucial for studying slab dehydration and melting mechanisms. Previous research has primarily focused on examining sediments and altered basalts collected near the seafloor, which has overlooked the chemical changes occurring within the forearc subduction channel. The Mariana forearc serpentinite mud volcanoes offer a
-
Magnesium isotope behavior during titanomagnetite fractionation in basaltic lavas Chem. Geol. (IF 3.9) Pub Date : 2024-04-07 Yang Sun, Fang-Zhen Teng, Tyrone O. Rooney, Kwan-Nang Pang, Ze-Zhou Wang
Knowledge of the behavior of magnesium (Mg) isotopes during magmatic differentiation is a prerequisite for applying Mg isotopes as a tracer of crustal recycling and mantle heterogeneity. Crystal fractionation of mafic silicate minerals leads to limited Mg isotope fractionation; hence, Mg isotopic variations in basalts largely result from contributions of subducted crustal materials into their mantle
-
High-precision microcline 40Ar/39Ar dating by combined techniques Chem. Geol. (IF 3.9) Pub Date : 2024-04-06 Xiu-Juan Bai, Yi-Long Li, Rong-Guo Hu, Xiao Liu, Bin Tang, Xiang-Ping Gu, Hua-Ning Qiu
K-feldspar is one of the most common minerals applied for Ar/Ar dating because of its high K content and ubiquitous presence. Excess Ar in K-feldspar resulting in unreliable ages has long been reported, however, its occurrence and trapping time are still inconclusive. Combined argon extraction techniques, including laser step heating, and step crushing, as well as succedent furnace incremental heating
-
An experimental study on the role of F−, PO43−, Cl− and SO42− ligands in the natrocarbonatite-nephelinite system at 850 °C and 0.1 GPa Chem. Geol. (IF 3.9) Pub Date : 2024-04-06 Dao-Ming Yang, Tong Hou, Roman E. Botcharnikov, Ilya V. Veksler, Francois Holtz, Zhaochong Zhang, Li Zhang, Antonia Simon, Nora Groschopf
Carbonatites and their comagmatic silicate rocks related deposit provide significant resources of rare earth elements (REEs), niobium (Nb) and other elements such as U, Th, Mo, V, Ba, Sr, etc. However, the genesis of mineralization, especially for REEs and Nb, in carbonatite remains enigmatic. Previous liquid immiscibility experiments have demonstrated that both REEs and Nb are preferentially enriched
-
Microscale heterogeneity of phosphorus species associated with secondary mineral phases in the B horizons of two boreal Podzols Chem. Geol. (IF 3.9) Pub Date : 2024-04-06 J.R. Marius Tuyishime, Tove Florén, Camille Rivard, Jon Petter Gustafsson
Poorly crystalline Al and Fe minerals have high sorption capacities for phosphate anions. However, there is still uncertainty about the molecular-level distribution of phosphorus (P) species between Al and Fe mineral phases, which can be relevant for bioavailability. The present study employed synchrotron X-ray microscopic techniques to distinguish between Al- and Fe-associated P phases in two Podzol
-
Mo-Mg isotopes trace the role of serpentinite in generating arc magmatism Chem. Geol. (IF 3.9) Pub Date : 2024-03-27 Qing-Chen Yang, Wei Fang, Li-Qun Dai, Zi-Fu Zhao, Guo-Chao Sun, Bing Gong
Serpentinite-derived components play an important role in chemical cycling in subduction zones. However, it is difficult to identify recycled serpentinite in subarc mantle due to the overprinting of other slab components, and how serpentinite contributes to arc magmatism is poorly understood. Here we report Mo and Mg isotopic compositions of Early Paleozoic Qushiang arc mafic rocks in the East Kunlun
-
Melting behavior of impure limestone under H2O-poor conditions: Implications for the contribution of carbonate-rich sediments to arc magmatic carbon output Chem. Geol. (IF 3.9) Pub Date : 2024-03-26 Juan Wang, Stephen Foley, Xiangfa Wang, Chao Wang, Yongsheng Liu
Sedimentary carbon may be transferred from subducting slabs to the overlying mantle wedge as a component of sediment-derived melts and contribute to carbon output in subduction zones. To investigate the melting behavior of subducting carbonate-rich sediments at shallow depths and evaluate the consequent efficiency of carbon recycling, this study presents the phase relations of HO-poor impure limestone
-
Speciation controls on Ni adsorption to birnessite and organo-birnessite Chem. Geol. (IF 3.9) Pub Date : 2024-03-26 Lena Chen, William B. Homoky, Caroline L. Peacock
Nickel (Ni) is an essential micronutrient for phytoplankton. Its importance to both the modern and ancient Earth system has encouraged development of Ni and its isotopes as biogeochemical tracers. To interpret these signatures however, understanding of how Ni and its isotopes are recorded in marine archives is required. Here we simulate different inorganic and organic Ni species in seawater and investigate
-
Heavy halogen impact on Raman water bands at high pressure: Implications for salinity estimations in fluid inclusions Chem. Geol. (IF 3.9) Pub Date : 2024-03-26 Tobias Grützner, Hélène Bureau
We present a new experimental dataset on the impact of the heavy halogens chlorine, bromine and iodine on the Raman water bands concerning pressure and their concentration at room temperature. These experiments were conducted at ambient temperature, with variations in halogen concentration and pressure ranging from 0 to 1.4 GPa.
-
Resetting the uraninite geochronometer metasomatically: The role of Na-Ca-F-OH-bearing fluids at 450 and 600 °C and 200 MPa Chem. Geol. (IF 3.9) Pub Date : 2024-03-25 Daniel E. Harlov, Michael Waitzinger, David Schiller, Fritz Finger
Uraninite [UO] is an increasingly recognized accessory mineral for geochronological studies of the mid to upper crust. Similar to what is seen for zircon and monazite, the U-Pb system of uraninite can become reset under relatively low temperatures in certain domains via the action of fluids through the process of coupled dissolution-reprecipitation. Whether or not the uraninite geochronometer is reset
-
Combined cadmium and chromium isotopes record a collapse of bioproductivity across the Cretaceous—Paleogene boundary in the Danish basin Chem. Geol. (IF 3.9) Pub Date : 2024-03-25 Jesper Allan Frederiksen, Nicolas Thibault, Geoffrey J. Gilleaudeau, Christian J. Bjerrum, Julien Moreau, Robert Frei
-
Linking the mercury biogeochemical cycle to the deep mercury cycle: A mercury isotope perspective Chem. Geol. (IF 3.9) Pub Date : 2024-03-25 Runsheng Yin, Xueyun Wang, Ruiyang Sun, Lingjian Gao, Changzhou Deng, Zhendong Tian, Anbo Luo, Bernd Lehmann
Mercury (Hg) is a volatile, bioaccumulative, and toxic heavy metal, and its global distribution is controlled by the Hg biogeochemical cycle in the atmosphere-land-ocean systems and the deep Hg cycle in interior reservoirs (e.g., mantle and crust). The biogeochemical cycle has been relatively well studied, but the deep Hg cycle remains relatively poorly constrained. Mercury isotopes undergo mass-dependent
-
Extracting paleo-weathering signals from authigenic phases in lake sediments: A case-study of Lake Baikal Chem. Geol. (IF 3.9) Pub Date : 2024-03-24 Tim Jesper Suhrhoff, Jörg Rickli, Marcus Christl, Elena G. Vologina, Alexander Prokopenko, Derek Vance
-
The relationship between iron redox states and H2O contents in back-arc basin basaltic glasses from the North Fiji Basin Chem. Geol. (IF 3.9) Pub Date : 2024-03-23 Hugh St.C. O'Neill, Andrew J. Berry, Leonid V. Danyushevsky, Trevor J. Falloon, Roland Maas, Sandrin T. Feig
Island-arc basalts (IAB) from convergent plate margins tend to have both higher iron oxidation states (higher Fe/Fe) and higher HO contents than the mid-ocean ridge basalts (MORB) produced by seafloor spreading, which raises the question of whether these two characteristics are causally related. Back-arc basin basalts (BABB) may help with this question, in that they are products of seafloor spreading
-
Triple oxygen isotope systematics of CO2 hydroxylation Chem. Geol. (IF 3.9) Pub Date : 2024-03-23 David Bajnai, Xiaobin Cao, Swea Klipsch, Andreas Pack, Daniel Herwartz
-
The history of serpentinisation at mid-ocean ridges: Insights from in situ trace elements coupled with oxygen and boron isotopes Chem. Geol. (IF 3.9) Pub Date : 2024-03-22 Coralie Vesin, Daniela Rubatto, Thomas Pettke
Oceanic serpentinisation is the principal process of water incorporation into the oceanic lithosphere, thus playing a significant role in the elements cycle. The conditions of serpentinisation vary in temperature, water-rock ratio, and fluid composition, but the investigation of the interplay of these factors, rather than their individual variation, is rarely attempted. This study examines mid-ocean
-
Variations in weathering conditions related to sea level changes during the Albian-Santonian interval in the Western Australian margin as evidenced by clay minerals and Nd/Sr isotopes Chem. Geol. (IF 3.9) Pub Date : 2024-03-22 Thomas Munier, Laurent Riquier, Sidonie Révillon, Armand Metgalchi, François Baudin
The Albian-Santonian interval (∼113–83 Ma) is a key interval for Cretaceous climatic and environmental changes. This interval is associated to a rise in sea level until the Late Cenomanian (∼ 94 Ma) and to a progressive increase in oceanic temperatures, leading to consider the Late Cenomanian-Santonian interval (∼ 94–83 Ma) as the warmest period of the last 200 Myr. While the Albian-Santonian interval
-
Controls of temperature and mineral growth rate on lithium and sodium incorporation in abiotic aragonite Chem. Geol. (IF 3.9) Pub Date : 2024-03-21 Jean-Michel Brazier, Anna L. Harrison, Claire Rollion-Bard, Vasileios Mavromatis
The use of Li/Ca, Na/Ca and Li/Mg ratios in biogenic aragonite exhibits high potential for reconstructing environmental parameters such as temperature and/or salinity. To date however, only a little is known about the mechanisms controlling the incorporation of monovalent metals such as Li and Na in aragonite. In this study, the effects of temperature and growth rate on Li and Na incorporation into
-
Geochemical proxies for deep-sea temperature and nutrient content in cold-water bamboo corals Chem. Geol. (IF 3.9) Pub Date : 2024-03-21 Thomas J. Williams, Christopher D. Standish, Philippe Archambault, Jasmin A. Godbold, Martin Solan, Orestis L. Katsamenis, Philip J. Basford, Gavin L. Foster
The impact of warming, acidification, and deoxygenation on deep-sea environments is a growing concern. Historical records are sparse, particularly at high latitudes, making climate change projections challenging. Indirect proxies, such as trace element composition of marine carbonates, such as coral skeletons, can offer an alternative method to fill data gaps but have not been realised. Here, using
-
Absence of a water depth signal in archaeal tetraether lipids from surface lake sediments in areas with intensive human activity: A case study from Daihai Lake, Inner Mongolia Chem. Geol. (IF 3.9) Pub Date : 2024-03-20 Zhongwei Shen, Yanwu Duan, Zhiping Zhang, Jie Chen, Lin Chen, Aifeng Zhou, Jianbao Liu, Fahu Chen
Indices based on isoprenoid glycerol dialkyl glycerol tetraethers (isoGDGTs) and hydroxylated GDGTs (OH-GDGTs), such as %Cren, Cren/Cren', and %OH-GDGTs, have been widely used as lake-level proxies in lake sediment cores. However, the interpretation of these indices is potentially complex and more research is needed to determine the contexts in which they can reliably be used for paleohydrological
-
Mineralogy-based stepwise dissolution of dolomitic limestone reveals high iodine content in water-column precipitated calcite and well‑oxygenated shallow seawater during the ∼1.57 Ga oxygenation event Chem. Geol. (IF 3.9) Pub Date : 2024-03-19 Hao Fang, Dongjie Tang, Limin Zhou, Ganqing Jiang, Xiaoying Shi, Liyuan Liang, Xiqiang Zhou, Longfei Sun, Baozeng Xie
Carbonate I/(Ca + Mg) has been used as a proxy to track shallow-seawater oxygen levels through Earth's history. However, due to diagenetic alteration and homogenization of iodine in carbonates formed in a redox-stratified water column or in porewater, bulk-rock I/(Ca + Mg) values—and thus the oxygen levels in Precambrian shallow seawater—could have been significantly underestimated. Here, we report
-
Refining granite generation by interrogation of zircon and monazite U-Th-Pb and Hf/Nd-O isotopes Chem. Geol. (IF 3.9) Pub Date : 2024-03-19 Xing Zhang, Yuanbao Wu, Bin Fu, Wenxiang Zhang, Long Li, Guangyan Zhou, Rui Li, Zhaochu Hu, Yu He, Zhengwei Qin
In-situ geochemical and isotopic analyses of zircon and monazite can provide compelling and detailed insights into the source and evolution of their hosting granite. Here we investigated the U-Th-Pb and Hf/Nd-O isotopic signatures of zircon and monazite in two petrological zones (i.e., fine- to medium-grained zone and medium-grained zone) of the Laojunshan granite pluton in the Qinling Orogen, central
-
Thermal history inversion from thermochronometric data and complementary information: New methods and recommended practices Chem. Geol. (IF 3.9) Pub Date : 2024-03-18 Richard A. Ketcham
Thermal history inverse modeling has become one of the primary platforms for interpreting thermochronometric data. This paper introduces new features in the HeFTy software, and compares them with both earlier HeFTy versions and other programs. The approach for combining multiple goodness-of-fit tests into a single probability has been changed to Fisher's method, improving both statistical accuracy
-
Sulfate affinity controls phosphate sorption and the proto-transformation of schwertmannite Chem. Geol. (IF 3.9) Pub Date : 2024-03-17 Karel As, Stefan Peiffer, Peter Onyisi Uhuegbue, Prachi Joshi, Andreas Kappler, Bouchra Marouane, Kerstin Hockmann
-
Neodymium isotope composition and rare earth element distribution of East Antarctic continental shelf and deep waters Chem. Geol. (IF 3.9) Pub Date : 2024-03-17 Alex Griffiths, Myriam Lambelet, Kirsty Crocket, Richard Abell, Barry J. Coles, Katharina Kreissig, David Porter, Frank O. Nitsche, Mark Rehkämper, Tina van de Flierdt
Circumpolar Deep Water (CDW) and Antarctic Bottom Water (AABW) play key roles in the Earth's climate system. Both water masses form critical components of the Antarctic Circumpolar Current and Meridional Overturning Circulation and therefore directly influence the large-scale redistribution of heat, nutrients and carbon. Reconstruction of past CDW transport and AABW production and export has been a
-
A conventional, molal-based Pitzer model for the (H+ – Nd3+ – NO3−){aq} system valid to stoichiometric ionic strengths near 40 mol·kg−1 at 298 K and 0.1 MPa Chem. Geol. (IF 3.9) Pub Date : 2024-03-16 Charles S. Oakes, Anderson L. Ward, Nikita Chugunov
Existing molal-based Pitzer activity coefficient models for (H + Nd + NO){aq} mixtures are either inaccurate, ill-formed, or do not span the ionic strength () range of the solid solubility data for the (H + Nd + ox + NO){aq} system. As a precedential step in developing a thermodynamic model for aqueous neodymium-oxalate-bearing systems, a speciated, conventional Pitzer model was fitted to the osmotic
-
Zircon-to-reidite phase transition enhanced by minor radiation damage: Implications for hypervelocity impacts Chem. Geol. (IF 3.9) Pub Date : 2024-03-16 Shuai Nan, Sisi Wang, Fuxiang Zhang, Jingjing Niu, Pengfei Zhai, Yingxin Liu, Lynn A. Boatner, Shan Qin, Jie Liu, Maik Lang, Rodney C. Ewing, Weixing Li
Reidite, a high-pressure phase of zircon, is increasingly identified at terrestrial impact sites. Despite its growing recognition, the potential applications for estimating minimum impact pressure face impediments due to existing discrepancies in the condition of zircon-reidite transformation, controversial models governing the transformation mechanism, and unclear effects of pre-existing radiation
-
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
-
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
-
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
-
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
-
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
-
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”
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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
-
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 paleoredox 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