Chemical Geology最新文献

{"title":"Kinec_v3: A computer database for the calculation of the dissolution rates of the major rock forming minerals","authors":"Eric H. Oelkers ,&nbsp;Mouadh Addassi","doi":"10.1016/j.chemgeo.2025.123041","DOIUrl":"10.1016/j.chemgeo.2025.123041","url":null,"abstract":"<div><div>The Kinec_v3 database allows the calculation of the dissolution rates of 133 major rock forming minerals in aqueous solutions at temperatures from 0 to 300 °C, pH from 0 to 14 and mineral saturation states from far-from-equilibrium to equilibrium. Calculated rates are generated using equations and parameters reported by Hermanska et al. (2022,2023) and Oelkers and Addassi (2025). The database has been created to be used in conjunction with the PHREEQC, but can be adapted for use in other computer algorithms that take into account fluid-mineral equilibria, mineral reactions and chemical transport. The Kinec_v3 database also allows for calculation of mineral precipitation rates consistent with dissolution rates using transition state theory based rate equations, yet such calculations are largely unverified at present, due to the dearth of available experimental measurements. The Kinec_v3 database is available to download from <span><span>https://github.com/Mou1a/Kinect_V3</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123041"},"PeriodicalIF":3.6,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uranium isotopes and trace element distributions in atmospheric dust mineral phases from the Sahara-Arabia Desert Belt","authors":"Gil Lapid,&nbsp;Adi Torfstein","doi":"10.1016/j.chemgeo.2025.123059","DOIUrl":"10.1016/j.chemgeo.2025.123059","url":null,"abstract":"<div><div>Atmospheric dust plays a key role in shaping global climate by affecting the radiative budget, modulating precipitation, and serving as an important source of limiting nutrients to the oceans. At present, the primary source of atmospheric dust in the world is the Sahara-Arabia Desert Belt (SADB). However, the mineralogical constituents of dust are highly variable and can be divided into several phases. Moreover, the chemistry of these phases changes from source to sink, over unknown time periods, due to chemical and physical weathering.</div><div>Here, we report (²³⁴U/²³⁸U) ratios and trace element concentrations in five sequentially leached phases of 18 dust samples collected in the Gulf of Aqaba, northern Red Sea, between 2013 and 2019. The sampling site is located between the Sahara and the Arabia Deserts, and exposed to frequent dust storms, whose source is identified through air mass back trajectories. The sequential leaching steps, successfully extracted the water labile, Ca‑carbonates, Fe<img>Mn oxides, Mg‑carbonates and silicate phases. The geochemical fingerprint and (²³⁴U/²³⁸U) ratios are used to identify sources and interaction between samples and phases.</div><div>This is the first report of the uranium isotopic composition of atmospheric dust from the eastern SADB. Coupled with trace element abundances, we characterize the end member compositions of each mineral phase, their provenance and transport time (i.e., comminution age). The latter spans over the last ∼200 kyrs for most samples, and longer (350–410 kyrs) for samples from the northern Arabian Peninsula. These results emphasize the fundamentally different sources and histories of dust across the SADB.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123059"},"PeriodicalIF":3.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Basalt melts under pressure: Is there really a viscosity minimum?","authors":"James K. Russell ,&nbsp;Kai-Uwe Hess ,&nbsp;Ana Anzulovic ,&nbsp;Donald B. Dingwell","doi":"10.1016/j.chemgeo.2025.123051","DOIUrl":"10.1016/j.chemgeo.2025.123051","url":null,"abstract":"<div><div>Basalts are the most numerous and voluminous magmas on Earth, the moon and other terrestrial planets and moons. Melt viscosity plays a major role in modulating the rates and efficacy of many magmatic and volcanic processes (e.g., melt extraction, ascent rates, eruption styles). The pressure dependence of melt viscosity is particularly relevant to basalts because of the wide range of pressures they experience during ascent from their mantle sources to Earth's surface. Here, we review and critically analyse the published high pressure experimental data for the viscosity of basaltic melts. Our compilation of high-pressure measurements of basalt viscosity is relatively sparse comprising a total of 56 experiments. The experiments span a temperature range of 1275 to 2000 °C, pressures from 0.5 to 7 GPa, and anhydrous melt compositions ranging from MORB, to Hawaiian tholeiite, to alkali olivine basalt (AOB). We focussed our analysis on nineteen modern falling sphere experiments on MORB (<span><span>Sakamaki et al., 2013</span></span>) and AOB (<span><span>Bonechi et al., 2022</span></span>) melts that were imaged with real-time, x-ray radiography. Our analysis of these data suggests a monotonic positive pressure dependence for basaltic melt viscosity. On that basis, we present a predictive model for the Newtonian viscosity of AOB melts as a function of temperature (T), pressure (P):<span><span><span><math><mi>log</mi><mspace></mspace><mi>η</mi><mo>=</mo><mo>−</mo><mn>4.55</mn><mo>+</mo><mfrac><mrow><mn>7845.4</mn><mo>+</mo><mn>295.4</mn><mspace></mspace><mfenced><mrow><mi>P</mi><mfenced><mi>GPa</mi></mfenced><mo>−</mo><mn>0.001</mn></mrow></mfenced></mrow><mrow><mi>T</mi><mfenced><mi>K</mi></mfenced></mrow></mfrac></math></span></span></span></div><div>A similar model applied to the MORB dataset is consistent with a significantly lower (i.e. 13.3 vs. 295.4) positive pressure coefficient implying a less pressure-dependent viscosity. Our observations call into question the concept of a minimum in the pressure dependence of basaltic melt viscosity which has been argued to inhibit the ascent of basaltic magmas.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123051"},"PeriodicalIF":3.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the robustness of uraninite UPb chronometer in complex hydrothermal uranium ore systems: Insights from Xiangshan volcanic-related uranium ore field, South China","authors":"Yongjian Wang ,&nbsp;Kezhang Qin ,&nbsp;Honghai Fan ,&nbsp;Yaqing Pang","doi":"10.1016/j.chemgeo.2025.123058","DOIUrl":"10.1016/j.chemgeo.2025.123058","url":null,"abstract":"<div><div>Accurate dating of hydrothermal uranium deposits has long been challenging due to the complex alteration of uranium minerals such as uraninite, which complicates the interpretation of U<img>Pb isotopic data. This study addresses this issue by presenting new U<img>Pb dating results from uraninite in the Xiangshan volcanic-related uranium ore field, South China, using in situ LA-ICP-MS. Through detailed petrographic observations and elemental scanning, we carefully selected well-preserved uraninite grains/veins that were minimally affected by post-mineralization alteration. The uraninite U<img>Pb geochronology yields the precise and reliable ²⁰⁸Pb-corrected U<img>Pb age of 137.0 ± 4.5 Ma and ²⁰⁴Pb-corrected U<img>Pb age of 139.1 ± 4.7 Ma, respectively, demonstrating remarkable consistency with the coeval hydrothermal apatite U<img>Pb age (ca. 135 Ma) obtained from the same hand specimen. Petrographic and elemental mapping analyses show that Pb-bearing minerals are commonly distributed as tiny particles along the microfractures or within the margins of the altered uraninite grains. This heterogeneity of Pb distribution is likely a result of fluid-aided modification induced by post-ore tectono-thermal events, which causes isotopic resetting and Pb loss, leading to inaccurate or misleading U<img>Pb ages. In addition, the presence of a large amount of anomalous Pb-bearing minerals (e.g., Pb-bearing molybdenum sulfide, pyrite) within the uraninite samples can also lead to younger-than-expected U<img>Pb ages. More importantly, the new mineralization age is, within error, nearly identical to the volcanic rock emplacement ages. This close temporal match, coupled with the geochemical signature of the uraninite, strongly suggests a genetic link between volcanic magmatism and uranium mineralization, indicating the Xiangshan uranium ore field might be formed during a short but continuous mineralization event rather than through a protracted and complex sequence of mineralization episodes. Additionally, this study highlights the need for careful interpretation of uraninite U<img>Pb dates in geologically complex uranium or uranium-associated ore systems.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123058"},"PeriodicalIF":3.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"40Ar/39Ar Geochronology of Meso-Cenozoic magmatism and its aqueous alteration, northern Santos Basin, South Atlantic","authors":"Paulo M. Vasconcelos ,&nbsp;Isabela O. Carmo ,&nbsp;Juliana Costa","doi":"10.1016/j.chemgeo.2025.123060","DOIUrl":"10.1016/j.chemgeo.2025.123060","url":null,"abstract":"<div><div>Reliable ages for magma emplacement are essential for assessing geodynamic models controlling the evolution of the South Atlantic and its prolific hydrocarbon-bearing sedimentary basins. Laser ⁴⁰Ar/³⁹Ar incremental-heating geochronology of single crystals, crystal ensembles, and groundmass fragments from nine distinct magmatic rocks – 18 incremental-heating spectra – from well 1-BRSA-905-RJ, northern Santos Basin, reveals three distinct magmatic events affected by several aqueous alteration episodes that partially reset the K-Ar clocks in the magmatic units. The oldest magmatic event at 71.4 ± 0.6 Ma records the extrusion of <em>E</em>-MORB-type magmas either subaerially onto volcanic edifices emerged from the ocean floor or as subaqueous lava flows onto the ocean floor. A second event, with two roughly coeval pulses at 50.02 ± 0.30 Ma and 50.63 ± 0.40 Ma, is recorded by two lamprophyric bodies, one intruded into the lower Cretaceous pre-salt sequence at 4201 m and another into Albian/Cenomanian sedimentary rocks at 3117 m. A third phonolitic magmatic event intruded into pre-salt units in the 4080-4087 m interval does not yield reliable geochronological results, but its best estimated intrusive age ranges from ∼50 to 43 Ma. All magmatic units have undergone aqueous alteration after 50 Ma, with significant alteration events at 43–40 Ma and as recently as ∼28 Ma that partially reset the magmatic ages. Magmatic events in the northern Santos Basin are coeval with magmatism along the continental margins in southeastern Brazil, suggesting a direct link between magma generation and emplacement on and offshore.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123060"},"PeriodicalIF":3.6,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of inorganic and organic carbon in the slab during subduction indicated by continental volcanic rock","authors":"Zheng Xu","doi":"10.1016/j.chemgeo.2025.123055","DOIUrl":"10.1016/j.chemgeo.2025.123055","url":null,"abstract":"<div><div>Continental volcanic rocks provide critical insights into carbon recycling processes within the mantle transition zone. Here I present the carbon isotope compositions of carbonates in the Cenozoic continental volcanic rocks from Eastern China. δ¹³C of carbonates in these rocks, which represent carbon isotope composition of the involved magma before carbonate precipitation, vary from −15.0 ‰ to −2.4 ‰. After the correction of magma degassing assuming the initial CO₂ content of the magma is 1500 ppm, the initial δ¹³C of the magma is between −13.6 ‰ to +6.2 ‰. Combining with degassing corrected carbon isotope compositions and whole rock trace element and Sr<img>Nd isotope compositions, these rocks can be divided into two groups, which includes samples with δ¹³C higher than DM and within or lower than DM. The distinction of carbon isotope compositions for the two groups can be attributed to the different proportions of high δ¹³C inorganic carbon and low δ¹³C organic carbon in the mantle sources. δ¹³C of these continental volcanic rocks are lower than arc emissions. This marks the consumption of inorganic carbon in the slab during decarbonation at sub-arc depth. The petrogenesis of continental volcanic rocks is related to the decarbonation in the mantle transition zone. However, δ¹³C of these rocks are comparable with OIB. This observation indicates the proportions of inorganic and organic carbon in the slab may not be significantly changed after decarbonation in the mantle transition zone.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123055"},"PeriodicalIF":3.6,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoupling of δ13Ccarb and δ13Corg during the Carnian Pluvial Episode in marine successions of South China","authors":"Enhao Jia ,&nbsp;Jacopo Dal Corso ,&nbsp;Kui Wu ,&nbsp;Yong Du ,&nbsp;Yuyang Wu ,&nbsp;Fengyu Wang ,&nbsp;Xu Dai ,&nbsp;Huyue Song ,&nbsp;Daoliang Chu ,&nbsp;Lei Zhong ,&nbsp;Zhiwei Yuan ,&nbsp;Xiangmin Chen ,&nbsp;Yuting Liu ,&nbsp;Zhe Li ,&nbsp;Haijun Song","doi":"10.1016/j.chemgeo.2025.123053","DOIUrl":"10.1016/j.chemgeo.2025.123053","url":null,"abstract":"<div><div>The Carnian Pluvial Episode (CPE) was a major climate change in the early Late Triassic. Multiple ¹³C negative excursions are widely considered to be key indicators of CPE and may be associated with the activity of Wrangellia large igneous province (LIP). However, it is still not clear whether the increased terrestrial inputs due to enhanced hydrological cycle during the CPE disturbed the isotope signal in marine settings. This study analyzed the high-resolution carbon isotopes and element geochemistry of three typical marine section (Xiashulao, Erguan, and Duanqiao) in South China. Decoupling between δ¹³C_carb and δ¹³C_org (2–3 ‰ negative shift of δ¹³C_carb vs 3–4 ‰ positive shift in δ¹³C_org) during CPE is observed at two shallow marine sections, i.e., Xiashulao and Erguan. No decoupling of δ¹³C_carb and δ¹³C_org was found in Duanqiao, which may relate to its location in a deep slope or basin environment, receiving fewer terrestrial inputs. This study reveals the regulating effect of depositional environmental differentiation on the carbon isotope record during the CPE and proposes a model of organic‑carbonate carbon isotope decoupling driven by terrestrial input.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123053"},"PeriodicalIF":3.6,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the phase associations and weathering behavior of rhenium to assess the use of Re as a tracer of georespiration","authors":"Layla Ghazi ,&nbsp;Miguel Goñi ,&nbsp;Brian Haley ,&nbsp;Jesse M. Muratli ,&nbsp;Julie C. Pett-Ridge","doi":"10.1016/j.chemgeo.2025.123026","DOIUrl":"10.1016/j.chemgeo.2025.123026","url":null,"abstract":"<div><div>Rhenium (Re) has been proposed as a tracer of petrogenic organic carbon (OC_petro) oxidation, also known as georespiration, but information regarding the solid phases hosting Re in rocks and Re weathering behavior is limited. Examining grey shale rocks from two small mountainous river basins in the Pacific Northwest, USA, we found that the majority of parent material (bedrock) Re in both basins is associated with OC_petro (average 71 %, range 50 to 93 %), with minimal Re hosted in sulfide minerals. In soil and weathered rock profiles, mass transfer calculations (τ) reveal a clear distinction between the weathering behavior of Re and that of other elements, indicating that Re weathering in these siliclastic rocks and soils does not primarily trace sulfide oxidation or dissolution of primary minerals. We find evidence that Re likely traces OC_petro oxidation, although patterns of Re and OC weathering are influenced by heterogeneity in bedrock composition and inputs of modern OC near the surface. In some cases Re loss exceeds that of OC during weathering, suggesting that the kinetics of Re oxidation are sometimes faster than those of OC oxidation. We observe greater Re loss in systems with slower erosion rate, which implies that systems subject to faster erosion export more unoxidized particulate Re. Our observations of Re phase associations and weathering behavior in soil and rock weathering profiles support the use of the Re proxy for georespiration, but also provide qualifications on its application in future work quantifying georespiration fluxes at regional and global scales.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123026"},"PeriodicalIF":3.6,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large volcanism, enhanced oceanic productivity, and efficient organic matter burial during Mesoproterozoic oxygenation events: Insights from mercury and carbon isotopes in the Jixian Group, North China Craton","authors":"Chenchen Yang ,&nbsp;Hua Guo ,&nbsp;Hu Huang ,&nbsp;Mingcai Hou ,&nbsp;Anbo Luo ,&nbsp;Runsheng Yin","doi":"10.1016/j.chemgeo.2025.123052","DOIUrl":"10.1016/j.chemgeo.2025.123052","url":null,"abstract":"<div><div>During the Mesoproterozoic, atmospheric O₂ levels were persistently low but interrupted by transient oxygenation events. The causes of these oxygenation events remain less clear. Large volcanism can transiently emit massive mercury (Hg), resulting in high Hg peaks in sedimentary successions. Here, we measure whole-rock rare earth elements and yttrium (REY) concentrations, Hg concentrations, and Hg isotope compositions across the Mesoproterozoic Jixian Group, North China Craton. REY concentrations mark two Mesoproterozoic oxygenation events (MOEs) in the Jixian Group, termed here as MOE1 (1.59 to 1.56 Ga) and MOE2 (1.48 Ga). Mercury peaks are observed at the bottom of MOE1 and MOE2 intervals, implying the presence of large volcanism. The two intervals are organic-rich and display positive excursions in Δ¹⁹⁹Hg values, which can be explained by enhanced input of volcanic Hg into the ocean and efficient scavenging of seawater Hg via organic burial. Combined with published carbon and sulfur isotopic data, we conclude that large volcanism during MOE1 and MOE2 could lead to increased input of nutrients into the ocean, which enhanced oceanic productivity to release abundant free O₂ into the atmosphere, and resulted in high organic matter burial rates and proliferation of heterotrophic microorganisms (e.g., sulfate-reducing bacteria), leading to euxinic conditions in deep seawater and enhanced precipitation of seawater-Hg. This work establishes a causal link between large volcanism and paleoenvironmental changes during MOEs.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123052"},"PeriodicalIF":3.6,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145093784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracking fluid sources in mantle wedge jadeitites: Petro-geochemical constraints and implications for fluid venting above the subduction interface","authors":"Clothilde Minnaert ,&nbsp;Samuel Angiboust ,&nbsp;Clément Herviou ,&nbsp;Raphael Melis ,&nbsp;Johannes Glodny ,&nbsp;Aitor Cambeses ,&nbsp;Tom Raimondo ,&nbsp;Justin Payne ,&nbsp;Thomas Rigaudier ,&nbsp;Juan Cárdenas-Párraga ,&nbsp;Clémentine Fellah ,&nbsp;Véronique Gardien ,&nbsp;Patrick Jame ,&nbsp;Erik Bonjour ,&nbsp;Antonio Garcia-Casco","doi":"10.1016/j.chemgeo.2025.123046","DOIUrl":"10.1016/j.chemgeo.2025.123046","url":null,"abstract":"<div><div>Jadeitites are commonly found in serpentinite mélanges and form by fluid flow across the subduction interface. Petrological analysis of jadeitites from various localities (Myanmar, Guatemala, Cuba, Russia, and Iran) coupled with structural characterization enabled the identification of successive jadeite/omphacite generations with subordinate amphibole and mica. These parageneses reflect metasomatism coeval with brittle and/or ductile deformation and complex crosscutting relationships. The composition of fluid inclusions (salinity, gas, δ¹⁸O, δD) reveals a wide range of fluid species pointing to a diversity of jadeitite-forming metasomatism. In situ trace element analysis and isotopic measurements (δ¹¹B, ⁸⁷Sr/⁸⁶Sr, δ¹⁸O) indicate a fluid source dominated by altered oceanic crust (AOC) with a minor sedimentary component. Despite marked changes in major element content during protracted metasomatism, trace elements evolve only moderately while isotopes are virtually homogeneous, recording only small variations of fluid composition over time. Jadeitite evolution is strongly related to the ongoing serpentinization of the mantle wedge, promoting a longer fluid time-residence at the interface associated with chemical exchange and pore-pressure build-up. This suggests that (i) First jadeite generations formed by percolation of highly channelized AOC-derived-fluids in a dry mantle wedge, while later generations record fluid interaction with sediments and the serpentinized mantle. (ii) Fluid pulses across the subduction interface and rheological behavior of the near interface mantle wedge are not controlled by drastic changes in the nature of the slab input, but rather by the cooling of the serpentinizing subduction environment. (iii) The re-use of the same fluid pathways above the slab promotes the re-equilibration of isotopic signatures. (iv) Overpressures may build up upon jadeitite formation and promote brittle deformation events. This may lead to switches in deformation style and variations in permeability, thus changing fluid flow mode along the base of the mantle wedge.</div></div>","PeriodicalId":9847,"journal":{"name":"Chemical Geology","volume":"695 ","pages":"Article 123046"},"PeriodicalIF":3.6,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}