Geochimica et Cosmochimica Acta最新文献

{"title":"Structure-informed prediction of organic matter thermodynamics from quantum chemistry and machine learning","authors":"Thomas P. Sibille, Klaus-Holger Knorr, Oliver J. Lechtenfeld, Maximilian P. Lau","doi":"10.1016/j.gca.2026.08.034","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.034","url":null,"abstract":"Thermodynamic constraints shape the degradation and persistence of dissolved organic matter (DOM) in aquatic environments. Predicting the Gibbs energy of the oxidation half reaction per mole of carbon (ΔG<ce:sup loc=\"post\">°</ce:sup><ce:inf loc=\"post\">(</ce:inf><ce:italic><ce:inf loc=\"post\">Cox</ce:inf></ce:italic><ce:inf loc=\"post\">)</ce:inf>) is therefore central to assessing the thermodynamic potential of organic matter degradation. A widely used approach is the linear relationship between nominal oxidation state of carbon (NOSC) and ΔG<ce:sup loc=\"post\">°</ce:sup><ce:inf loc=\"post\">(</ce:inf><ce:italic><ce:inf loc=\"post\">Cox</ce:inf></ce:italic><ce:inf loc=\"post\">)</ce:inf>, introduced by LaRowe and Van Cappellen, which provides a convenient and versatile single-proxy estimate. However, NOSC is a stoichiometric descriptor and assigns identical ΔG<ce:sup loc=\"post\">°</ce:sup><ce:inf loc=\"post\">(</ce:inf><ce:italic><ce:inf loc=\"post\">Cox</ce:inf></ce:italic><ce:inf loc=\"post\">)</ce:inf> values to formulae that reflect structures differing by more than 90 kJ molC<ce:sup loc=\"post\">-1</ce:sup>. This underlying diversity of structures can be isomeric, but can also reflect variation in molecular size, heteroatom composition, hydrogen abundance, and level of unsaturation. Here we present a structure-informed Random Forest model for ΔG<ce:sup loc=\"post\">°</ce:sup><ce:inf loc=\"post\">(</ce:inf><ce:italic><ce:inf loc=\"post\">Cox</ce:inf></ce:italic><ce:inf loc=\"post\">)</ce:inf> trained on a curated set of over 3,500 quantum-chemically calculated DOM-relevant molecules spanning diverse elemental compositions and structures. The model was trained using formula-derived descriptors, including elemental ratios, molecular mass (M<ce:inf loc=\"post\">r</ce:inf>), double bond equivalence (DBE), heteroatom content, NOSC and others. Predictions are made at the molecular level and represent an average across potential isomers of a formula. It relies on ΔG<ce:sup loc=\"post\">°</ce:sup><ce:inf loc=\"post\">(</ce:inf><ce:italic><ce:inf loc=\"post\">Cox</ce:inf></ce:italic><ce:inf loc=\"post\">)</ce:inf> data derived with the Becke three-parameter Lee-Yang-Parr density functional (B3LYP) and captures thermodynamic variability that the NOSC-based linear relationship systematically misses. As proof of concept, the model was applied to ultra-high resolution mass spectrometry (UHR-MS) data for four benchmark DOM reference materials, yielding ΔG<ce:sup loc=\"post\">°</ce:sup><ce:inf loc=\"post\">(</ce:inf><ce:italic><ce:inf loc=\"post\">Cox</ce:inf></ce:italic><ce:inf loc=\"post\">)</ce:inf> distributions that are broader and multimodal compared to the NOSC-based estimates. These results demonstrate that machine learning models grounded in quantum chemical data provide a more differentiated thermodynamic representation of DOM formula space and support improved prediction of organic matter oxidation potential.","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"35 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148885179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mg-Ca-Sr-Nd isotopes of orogenic peridotites from the North Qaidam orogen tracing deep carbon transfer during continental collision","authors":"Zhuang-Zhuang Yin, Ren-Xu Chen, Guo-Chao Sun, Zi-Xuan Wang, Bing Gong, Xiang-Ping Zha","doi":"10.1016/j.gca.2026.08.035","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.035","url":null,"abstract":"Subduction serves as the primary mechanism for recycling surface materials into the mantle. While the carbon cycle in oceanic subduction zones has been extensively studied, the migration, storage and speciation of carbon in continental subduction zones remain poorly understood. Here, we present an integrated study of whole-rock major and trace element compositions, Sr-Nd-Ca-Mg isotopes and in situ clinopyroxene major-trace elements and Sr isotopes in orogenic peridotites from the North Qaidam orogen, Tibetan Plateau. The results show that the garnet peridotites originated from highly depleted subcontinental lithospheric mantle and experienced variable degrees of metasomatism. Garnet dunites and garnet lherzolites exhibit higher &lt;ce:italic&gt;δ&lt;/ce:italic&gt;&lt;ce:sup loc=\"post\"&gt;44/40&lt;/ce:sup&gt;Ca values (0.96 ± 0.08‰ to 1.22 ± 0.13‰) than the normal mantle (0.94 ± 0.05‰), indicating modification by partial melting. From garnet dunites through garnet lherzolites to garnet pyroxenites, Ca content increases while &lt;ce:italic&gt;δ&lt;/ce:italic&gt;&lt;ce:sup loc=\"post\"&gt;44/40&lt;/ce:sup&gt;Ca decreases progressively, indicating metasomatism by a light-Ca-enriched agent. These ultramafic rocks have nearly uniform δ&lt;ce:sup loc=\"post\"&gt;26&lt;/ce:sup&gt;Mg values (−0.37 ± 0.03‰ to −0.17 ± 0.05‰), slightly lower than or consistent with the normal mantle, suggesting metasomatism by a light-Mg-enriched agent. The combined Ca-Mg isotopic systematics point to metasomatism by carbonate-bearing fluids. High &lt;ce:sup loc=\"post\"&gt;87&lt;/ce:sup&gt;Sr/&lt;ce:sup loc=\"post\"&gt;86&lt;/ce:sup&gt;Sr and negative ε&lt;ce:inf loc=\"post\"&gt;Nd&lt;/ce:inf&gt;(t) values further indicate metasomatism by a silicate melt derived from subducted granitic gneiss. Clinopyroxenes show high Ca/Al, (La/Yb)&lt;ce:inf loc=\"post\"&gt;N&lt;/ce:inf&gt;, and Nb/Yb ratios, consistent with carbonatitic melt metasomatism, however their covariation of Zr/Hf and Ti/Eu ratios deviate from typical carbonate metasomatism. Together with the high &lt;ce:sup loc=\"post\"&gt;87&lt;/ce:sup&gt;Sr/&lt;ce:sup loc=\"post\"&gt;86&lt;/ce:sup&gt;Sr ratios, these features suggest that the metasomatic agent was not a pure carbonatitic melt but a carbonated silicate melt, generated by reaction between carbonate and silicate melt derived from subducted continental crust. However, the low MgO content of carbonated silicate melts is insufficient to explain the Mg isotopic fractionation observed in the Lüliangshan peridotites. Instead, the P-T conditions and zircon characteristics indicate incorporation of carbonate into refractory peridotites via supercritical fluids, which effectively induced the observed Mg isotopic fractionation. Geochronological constraints suggest that Mg-rich supercritical fluid metasomatism likely occurred during ultrahigh-pressure metamorphism, whereas carbonated silicate melt metasomatism took place during slab exhumation. Thus, continental subduction can transfer substantial surface carbon into the subcontinental lithospheric mantle, with potential later recycling to the surface via post-collisio","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"5 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148885177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multicomponent diffusion in basaltic to andesitic melts: Toward a temperature- and composition-independent eigenvector matrix","authors":"Bobo Bai, Youxue Zhang","doi":"10.1016/j.gca.2026.08.031","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.031","url":null,"abstract":"Multicomponent diffusion in natural silicate melts controls many igneous processes such as magma mixing and crystal growth. In <mml:math altimg=\"si33.svg\"><mml:mi>N</mml:mi></mml:math>-component silicate melts, multicomponent diffusion is characterized by an <mml:math altimg=\"si34.svg\"><mml:mrow><mml:mfenced close=\")\" open=\"(\"><mml:mrow><mml:mi>N</mml:mi><mml:mo linebreak=\"badbreak\">-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:mfenced><mml:mo>×</mml:mo><mml:mfenced close=\")\" open=\"(\"><mml:mrow><mml:mi>N</mml:mi><mml:mo linebreak=\"badbreak\">-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:mfenced></mml:mrow></mml:math> diffusion matrix <mml:math altimg=\"si35.svg\"><mml:mrow><mml:mo stretchy=\"false\">[</mml:mo><mml:mi>D</mml:mi><mml:mo stretchy=\"false\">]</mml:mo></mml:mrow></mml:math>, whose eigenvectors define <mml:math altimg=\"si36.svg\"><mml:mrow><mml:mi>N</mml:mi><mml:mo linebreak=\"badbreak\" linebreakstyle=\"after\">-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:math> eigen-components that diffuse independently. Each eigenvalue is the diffusion coefficient for the corresponding eigen-component. Previous studies demonstrated that diffusion eigenvectors in 8-component SiO<ce:inf loc=\"post\">2</ce:inf>-TiO<ce:inf loc=\"post\">2</ce:inf>-Al<ce:inf loc=\"post\">2</ce:inf>O<ce:inf loc=\"post\">3</ce:inf>-FeO-MgO-CaO-Na<ce:inf loc=\"post\">2</ce:inf>O-K<ce:inf loc=\"post\">2</ce:inf>O basaltic melts are roughly invariant with temperature. In this work, we extend this investigation to andesitic compositions to test the temperature independence of diffusion eigenvectors in more evolved melts. Thirteen diffusion couple experiments were carried out at 1250, 1350, and 1500 °C: twelve andesite-andesite couples and one basalt-andesite couple. Diffusion profiles from the twelve andesite-andesite diffusion couple experiments can be fit simultaneously with a single eigenvector matrix, supporting the hypothesis that the eigenvectors are temperature invariant in andesitic melts.","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"25 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148885182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron isotopes reveal the transition from magmatic to hydrothermal systems in highly evolved granites","authors":"Yikang Quan,Jiaru Sheng,Gengxin Deng,Yan Jing,Xiangyu Yan,Fang Huang","doi":"10.1016/j.gca.2026.09.002","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.002","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"7 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond the Urey-Craig diagram: a ternary framework for iron redox evolution during aqueous alteration of carbonaceous chondrites","authors":"Damanveer S. Grewal,Zhongtian Zhang","doi":"10.1016/j.gca.2026.08.036","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.036","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clumped isotope evidence for methane cycling in coastal aquatic system","authors":"Xinchu Wang, Xu Zhang, Wei Guo, Hu Ding, Jiarui Liu, Rob M. Ellam, Si-Liang Li, Cong-Qiang Liu","doi":"10.1016/j.gca.2026.08.032","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.032","url":null,"abstract":"Methane is a potent greenhouse gas that plays an important role in Earth’s climate change. The aquatic methane emissions are dynamic hotspots, while the cause of high variability of methane fluxes is uncertain given the complexity of multiple, overlapping microbial processes in methane cycling. Here, we investigated methane cycling across a salinity gradient in a coastal aquatic system (CAS) by integrating the relative abundances of doubly substituted “clumped” methane isotopologues (<ce:sup loc=\"post\">13</ce:sup>CH<ce:inf loc=\"post\">3</ce:inf>D and <ce:sup loc=\"post\">12</ce:sup>CH<ce:inf loc=\"post\">2</ce:inf>D<ce:inf loc=\"post\">2</ce:inf>) with field surveys, bulk isotopes and metagenomic sequencing. We found that methane production involved mixed methanogenic pathways, while spatially variable methane oxidation overprinted these primary signals. Two contrasting clumped isotope patterns were observed: (1) In saline zones, methane has high Δ<ce:sup loc=\"post\">13</ce:sup>CH<ce:inf loc=\"post\">3</ce:inf>D but low Δ<ce:sup loc=\"post\">12</ce:sup>CH<ce:inf loc=\"post\">2</ce:inf>D<ce:inf loc=\"post\">2</ce:inf> values, consistent with strong kinetic and/or combinatorial isotope effects. (2) In freshwater zones, clumped isotope signatures shift from depleted toward more enriched value. Yet, despite Δ<ce:sup loc=\"post\">13</ce:sup>CH<ce:inf loc=\"post\">3</ce:inf>D and Δ<ce:sup loc=\"post\">12</ce:sup>CH<ce:inf loc=\"post\">2</ce:inf>D<ce:inf loc=\"post\">2</ce:inf> moving partly toward thermodynamic equilibrium, kinetic isotope effects remain expressed. Taken together, the observed clumped isotope patterns reflect a combination of mixing, kinetic effects, and partial isotope exchange. Metagenomic and functional gene data further supported the coexistence of methane production and oxidation potential across the CAS, providing independent biological evidence for the processes inferred from the isotope systematics. We interpret the partial isotope exchange as low reaction reversibility linked to rate-limiting enzyme, methyl coenzyme M reductase (MCR) complex, which catalyzes the last step of methanogenesis and the first step of methanotrophy. Thus, clumped isotope data improve our understanding of methane biogeochemical cycling and hence provide new insights into methane estimation in Earth system models.","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"38 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148885350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Textures of Chassignite meteorites: Clues to cumulate formation and early deformation processes on Mars","authors":"N. Meunier-Mili, M.-A. Kaczmarek, M. Bystricky","doi":"10.1016/j.gca.2026.08.025","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.025","url":null,"abstract":"Chassignite meteorites are martian achondrites that display a magmatic cumulate texture and are mainly composed of olivine with a small amount of poikilitic pyroxene. This study presents a detailed petrological and microstructural analysis using electron backscatter diffraction of all Chassignite meteorites documented up to now, Chassigny, NWA 2737 and NWA 8694, in order to decipher early magmatic, deformation and shock processes. The new results reveal that olivine crystals in Chassignite meteorites initially formed through synneusis, a magmatic process where individual crystals accumulate and aggregate together in specific orientations in the earlier stages of consolidation. Many olivine crystals stick together along (100) crystalline faces as evidenced by the significant concentration of misorientation [100] axes at grain boundaries for all three samples. Synneusis was probably interrupted and progressively replaced by crystal settling until complete crystallisation was achieved. Olivine crystallographic preferred orientations indicate slip on [100](010) and olivine subgrain boundaries reveal high densities of geometrically necessary dislocations of the [100](010) type. The [100](010) slip system is active at high temperatures and low stresses in the Earth’s upper mantle and is often observed in plastically deformed peridotites, though it is not necessarily dominant in terrestrial olivine cumulative rocks. Furthermore, pyroxene crystallographic preferred orientations are consistent with those of olivine ([100] olivine axes parallel to pyroxene [001] axes), supporting the hypothesis of minor plastic deformation of olivine and pyroxene at high temperatures and low stresses. These observations are consistent with possible crystallization and emplacement of the Chassignite magma in the shallow Martian crust. Finally the strong shock events recorded by these meteorites is supported by significant internal deformation of olivine grains, concentration of misorientation axes along their [100] axes, and the activation of the [001](010) slip system leading to formation of olivine subgrain boundaries. Altogether these results are good indicators to decipher primary planetary processes.","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"15 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148885181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Redox overprinting and anthropogenic source shifts recorded by mercury isotope systematics in Eastern Mediterranean deep-sea sediments","authors":"Xiaowei Chen, Daniel Cossa, Jiawang Wu, Lars-Eric Heimbürger-Boavida, Songjing Li, Zhao Wang, Steph Guédron, Wang Zheng, Yi Liu, Jiubin Chen, Ruoyu Sun","doi":"10.1016/j.gca.2026.08.033","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.033","url":null,"abstract":"Deep-sea sediments constitute long-term archives of mercury (Hg) burial, yet the chronological record can be biased by post-depositional diagenetic processes, particularly in areas with high organic matter export and redox variations. We present Hg stable isotope data from Holocene deep-sea sediment cores of the Ionian Sea (Eastern Mediterranean) to quantify how depositional redox conditions, early diagenesis, and anthropogenic forcing shape sedimentary Hg systematics. The distinct, organic-rich sapropel S1 developed during the early Holocene provides a natural redox perturbation experiment. During sapropel formation, Hg concentrations and accumulation rates increased markedly in concert with organic carbon burial, reflecting efficient scavenging of dissolved seawater Hg under enhanced productivity and stratified water-column conditions with reduced deep-water ventilation. Hg isotope signatures remained invariant and indistinguishable from background sediments, implying minimal isotopic fractionation during primary deposition and preservation of contemporaneous seawater isotope signatures. In contrast, post-depositional oxidation (“burn-down”) of the sapropel induced substantial Hg remobilization and redistribution across redox fronts, generating pronounced negative excursions in δ&lt;ce:sup loc=\"post\"&gt;202&lt;/ce:sup&gt;Hg (up to ∼1.6‰, relative to background) coincident with manganese and molybdenum enrichments. These shifts suggest that early diagenesis imposed strong mass-dependent fractionation (MDF), most likely during oxidative mobilization and subsequent re-immobilization of Hg into authigenic phases. Throughout sapropel deposition and oxidation, mass independent fractionation (MIF, Δ&lt;ce:sup loc=\"post\"&gt;199&lt;/ce:sup&gt;Hg and Δ&lt;ce:sup loc=\"post\"&gt;200&lt;/ce:sup&gt;Hg) remained largely unaffected, indicating that Hg MIF signatures appear insensitive to these post-depositional processes and may preserve surface-derived signatures. The upper oxic sediments in the late Holocene show little impact of redox-driven diagenesis on Hg and record two isotopically distinct anthropogenic phases. A modest Hg enrichment during the late Iron Age–Roman period is characterized by elevated δ&lt;ce:sup loc=\"post\"&gt;202&lt;/ce:sup&gt;Hg and near-zero Δ&lt;ce:sup loc=\"post\"&gt;199&lt;/ce:sup&gt;Hg values, consistent with lateral transport of local metallurgical residues. In contrast, Industrial Era sediments display sharply increased Hg enrichment accompanied by lower δ&lt;ce:sup loc=\"post\"&gt;202&lt;/ce:sup&gt;Hg and slightly positive Δ&lt;ce:sup loc=\"post\"&gt;199&lt;/ce:sup&gt;Hg values, suggesting dominant inputs from industrial Hg emissions at a broader scale. Together, these results suggest that sedimentary Hg isotopes preserve both depositional and diagenetic information. When interpreted within a stratigraphically constrained redox framework, paired MDF–MIF systematics provide a robust approach for disentangling redox overprinting from source variability, thereby strengthening the reliability of marine sediments as archi","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"6 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148885178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biogeochemical controls on dissolved micronutrient (Ni, Cu, Zn, Cd) distributions in the Equatorial Pacific Ocean","authors":"Naman D. Singh,Zvi Steiner,Rena Czeschel,Peter Brandt,Yuping Guo,Xue-Gang Chen,Jana Blanke,Angèle Nicolas,Jinqiang Guo,Kathleen J. Gosnell,Edel M. O’Sullivan,Dominik Jasinski,André Mutzberg,Tim Steffens,Eric P. Achterberg","doi":"10.1016/j.gca.2026.08.026","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.026","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"35 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Platinum occurs as α-PtO2 nanoparticles in deep-sea ferromanganese deposits","authors":"Jianlin Liao,Yan Li,Julien Léger,Andrea Koschinsky,Catherine Dejoie,Anne-Claire Gaillot,Irina Snigireva,Andrea Giacomelli,Stephan N. Steinmann,Olivier Mathon,Alain Manceau","doi":"10.1016/j.gca.2026.08.030","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.030","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"75 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148893595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}