Geochemistry Geophysics Geosystems最新文献

{"title":"Multiple Subduction–Exhumation Cycles and Episodic Hydration–Metasomatism of an Oceanic Eclogite Block: Implications for Thermal Structure Evolution and Mass Transfer at the Subduction Interface","authors":"Dadi Cao,&nbsp;Liqing Xu,&nbsp;Xiangxin Zhang,&nbsp;Haofan He,&nbsp;Kang Cheng","doi":"10.1029/2026GC013168","DOIUrl":"https://doi.org/10.1029/2026GC013168","url":null,"abstract":"<p>The rarity of natural rocks that specifically record the physicochemical conditions of the subduction interface strongly hampers pertinent studies on metamorphic trajectories of high-pressure (HP) rocks and related fluid–rock interactions. This study examines an oceanic eclogite block from the Huwan shear zone in the Hong'an orogen. Eclogites from different domains exhibit considerable differences in texture, mineral assemblage, and major-element zoning patterns. Pseudosection modeling and geothermobarometry on representative eclogites yield distinct pressure–temperature (<i>P</i>–<i>T</i>) paths with divergent evolutionary vectors. Coupled Lu–Hf and Sm–Nd dating on an eclogite with three garnet generations yields a reverse age relationship, with the Lu–Hf date (273.7 ± 0.6 Ma) approximately constraining the growth age of the garnet rim given its higher weight fraction of Lu. Multiple age clusters of metamorphic zircons (∼353–237 Ma) are interpreted as reflecting the time of disparate HP metamorphic events. Combined with previous data, a long-term yo-yo-like path is delineated in response to multiple subduction–exhumation cycles within the subduction interface. We attribute the discrepant <i>P</i>–<i>T</i> estimates and isotopic dates of eclogites to the formation of reaction rinds through episodic hydration–metasomatism, facilitated by externally derived aqueous, carbon-bearing, and sulfur-bearing fluids. The block records a higher geothermal gradient than other eclogites, attributed to the combined effects of subduction-interface geotherms, exothermic hydration, and potential shear heating. Within the interface, reduced sulfur species (e.g., HS⁻) in up-dip migrating fluids can be effectively filtered by reprecipitating as pyrite through redox reactions with detached HP rocks, sometimes accompanied by carbonate dissolution and silica metasomatism.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013168","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pre-Eruptive Volatiles and Magma Storage Depth for the 2018 Eruption at Mount Veniaminof, Alaska","authors":"E. G. Huggins,&nbsp;P. Ruprecht,&nbsp;M. Loewen,&nbsp;M. Gavrilenko,&nbsp;R. J. Bodnar,&nbsp;M. Harlaux","doi":"10.1029/2025GC012518","DOIUrl":"https://doi.org/10.1029/2025GC012518","url":null,"abstract":"<p>Mount Veniaminof is a frequently active, open-system arc volcano on the Alaska Peninsula, part of the Alaska-Aleutian arc. Mount Veniaminof's September–December 2018 eruption began with small lava flows and culminated in a larger explosive event in November that produced a 450 km long continuous ash plume—one of the volcano's most significant ash-producing events in recently observed eruptions. A temporally constrained tephra record was sampled after the eruption. We present volatile element concentrations (H, C, S, Cl, F) from a total of 65 olivine-hosted melt inclusions (MIs) across six tephra layers to assess potential variations in magma chemistry throughout the course of the eruption. No variation is observed in volatile concentrations across the tephra layers, and there is no correlation between volatile concentrations and the explosivity of eruptive pulses leading to the November explosive event. H₂O concentrations within MI suggest moderately hydrous magmas up to 2.4 wt% H₂O and a large range in CO₂ concentrations in the MI (14–2,180 ppm) from Secondary Ion Mass Spectrometry and vapor bubble reconstructions. H₂O and CO₂ measurements correspond to entrapment pressures up to 400 MPa (entrapment depths ∼15 km), but with modal storage around 100–200 MPa. H₂O contents can be reconciled with previous microlite number density estimates using a polybaric storage history.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012518","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Size of Greater India: Estimates by Comparing the Apparent Polar Wander Paths of the Tethyan Himalaya and the Indian Craton","authors":"Xianwei Jiao,&nbsp;Suo Wang,&nbsp;Yong Zhao,&nbsp;Tongming Fang","doi":"10.1029/2026GC013189","DOIUrl":"https://doi.org/10.1029/2026GC013189","url":null,"abstract":"<p>The northern extent of Greater India is a critical, yet highly debated, parameter for reconstructing the India-Asia collision. Previous paleomagnetic estimates, including the fill-the-gap and fixed great circle approaches, yield widely varying results, spanning from ∼200 to ∼3,000 km. These large discrepancies stem principally from two primary issues: the inherent uncertainties associated with both the Tethyan Himalaya (TH) and Indian apparent polar wander paths (APWP) based on paleomagnetic and geochronologic data, and India's complex kinematic history, particularly the large rotation in the Early Cretaceous followed by rapid northward translation in the Late Cretaceous. Because of limited data coverage from TH, discrete age-matched comparisons between them compound these uncertainties. To address this, we introduce a refined APWP-constrained approach that evaluates the TH paleomagnetic record as a temporal sequence. Assuming a coherent rigid attachment, this framework iteratively translates the TH northward, systematically quantifying the discrepancies between its restored paleomagnetic poles and the coeval poles expected from the updated Indian APWP while propagating uncertainties in both pole position and age using Monte Carlo simulations. Applying this to paleomagnetic data from the Jurassic–Paleocene units with age reassessment, we identify a statistically minimized discrepancy following a 7.9 ± 1.2° northward shift, which likely represents the pre-shortening northern margin of Greater India. This optimal shift translates directly to a crustal shortening estimate of ∼880 km, consistent with geologic records of Greater India. This refined estimate provides a constraint for the India-Asia collision and facilitates improved tectonic models of the Tibetan Plateau.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013189","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Authigenic Be Isotopes Record Circumpolar Deep Water Inflow and Subglacial Outflow in Antarctic Shelf Sediments","authors":"Yuri Yamazaki,&nbsp;Yusuke Suganuma,&nbsp;Takuya Itaki,&nbsp;Atsuko Amano,&nbsp;Takeshige Ishiwa,&nbsp;Daisuke Hirano,&nbsp;Motohiro Hirabayashi,&nbsp;Hiroyuki Matsuzaki,&nbsp;Takeyasu Yamagata,&nbsp;Yuki Tokuda,&nbsp;Takeshi Sugimura,&nbsp;Takeshi Tamura,&nbsp;Kazuya Kusahara,&nbsp;Jun'ichi Okuno,&nbsp;Kosei E. Yamaguchi","doi":"10.1029/2026GC012975","DOIUrl":"https://doi.org/10.1029/2026GC012975","url":null,"abstract":"<p>The Antarctic Ice Sheet (AIS) has recently undergone accelerating mass loss driven primarily by basal melting associated with Circumpolar Deep Water (CDW) inflow onto the continental shelf. However, temporal variability in CDW inflow and its role in mass loss from the AIS over longer timescales remain uncertain because the duration of the observational record is too short to refine future projections. Robust proxies are therefore needed to reconstruct past CDW inflow and AIS variability. Although beryllium (Be) isotopes in marine sediments have been used to trace meltwater input, recent studies have challenged this interpretation, suggesting that ¹⁰Be may instead reflect deep-ocean currents, such as CDW. Here, we investigate the spatial distribution of authigenic Be isotopes in surface marine sediments from two fast-flowing ice stream regions of East Antarctica and combine satellite with in situ oceanographic observations to evaluate Be isotope sources. Our results indicate that ¹⁰Be concentrations and ¹⁰Be/⁹Be ratios increase along the CDW pathway and decrease from offshore to the ice shelf front. Notably, the spatial distribution of ¹⁰Be is not correlated with the extent of seasonal sea ice. These findings suggest that CDW inflow is the dominant control on ¹⁰Be distributions. In contrast, ⁹Be concentrations are higher near the ice shelf front, likely reflecting sediment delivery from beneath the AIS, and may serve as indicators of subglacial meltwater. These findings highlight the potential of authigenic Be isotopes in Antarctic marine sediments to serve as proxies for reconstructing past variability in both CDW and AIS dynamics.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC012975","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149146616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Stage Evolution of Subducted Oceanic Mantle: The Marlborough Ultramafic Suite (New England Orogen, Australia)","authors":"J. A. Pasco,&nbsp;G. Rosenbaum,&nbsp;T. Ubide,&nbsp;L. A. Milan,&nbsp;C. Spier","doi":"10.1029/2026GC012973","DOIUrl":"https://doi.org/10.1029/2026GC012973","url":null,"abstract":"<p>Oceanic lithosphere is continuously destroyed by subduction, challenging our ability to develop tectonic reconstructions. One way to tackle this problem is to examine relics of once-consumed oceanic domains preserved along convergent margins. In the New England Orogen (eastern Australia), disrupted exposures of ultramafic rocks loosely define a continuous trend. The exposures may represent vestiges of ancient oceanic lithosphere that existed along the eastern Gondwanan margin. To investigate the origin and evolution of this ultramafic belt, we obtained new petrological and geochemical data from the Marlborough Ultramafic Suite, the largest ultramafic massif in eastern Australia. It comprises harzburgite, serpentinite, and high-grade serpentinite. Major and rare earth element systematics resemble residual abyssal peridotites from mid-ocean ridges. The rocks preserve early lizardite serpentinization and evidence of high-temperature fluid–rock interaction that took place at or near the ocean floor. High bulk alkali/U ratios indicate a shift into subduction, supported by the formation of prograde antigorite and talc. Magnesian olivine (Fo₉₅) in high-grade serpentinite is attributed to subduction-related prograde metamorphism. Based on the petrological signatures, we suggest that abyssal peridotites from the Paleo-Pacific Ocean were subducted beneath eastern Gondwana. Slivers of the slab were detached and mixed in the subduction channel before being exhumed and accreted onto the accretionary complex. Our results provide new constraints on the evolution of a once-consumed oceanic domain along the eastern Gondwanan margin, offering insight into the fate of the oceanic lithosphere upon subduction.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC012973","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Block and Bomb Field of the 1888–1890 CE Eruption at La Fossa Cone (Vulcano, Aeolian Islands): Constraints on Conduit Stratigraphy and Eruptive Dynamics","authors":"P. Gabellini,&nbsp;R. Cioni,&nbsp;M. Pistolesi,&nbsp;P. Donato,&nbsp;R. De Rosa","doi":"10.1029/2026GC012928","DOIUrl":"https://doi.org/10.1029/2026GC012928","url":null,"abstract":"<p>Vulcanian eruptions are classically associated with the launch of ballistic ejecta and particularly with the production of breadcrust bombs. Morpho-textural analysis of these ejecta provides critical insight into the poorly constrained processes controlling the complex dynamics of Vulcanian activity. Here, we present results from extensive fieldwork describing lithology, grain size, and spatial dispersal of ballistic products from the 1888–1890 CE eruption at La Fossa cone (Vulcano, Aeolian Islands). A dedicated strategy adopted during the field survey allowed us to investigate ballistics across the whole crater terrace and recognize a marked lithological diversity in the erupted products. Six types of ballistics were distinguished based on lithological, structural and textural features: Dense blocks [D]; Breccias-bearing Dense blocks [D-Br]; Black Scoria bombs [S]; and breadcrust bombs [BcB] with three sub-categories based on external rind features: thick crusted [BcB-Tk], thin crusted [BcB-Tn] and vesicular rind [BcB-Vr]. Dense blocks are the dominant ballistic product, representing up to 70 wt% of the total deposit, while breadcrust bombs account for only 20–25 wt%. The spatial dispersal of different bomb types is highly variable across the crater terrace in terms of both size distribution (modes around −7 Φ) and textural features. By combining measured data with direct observations from historical chronicles, we reconstruct the syn-eruptive conduit stratigraphy at Vulcano for this eruption. The eruptive dynamics of this archetypal Vulcanian activity was interpreted as mostly controlled by gas accumulation and fragmentation of an intensely fractured and slowly ascending viscous magma plug, which was only occasionally remobilized by the arrival of lower viscosity, volatile-richer magma from the deeper system.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC012928","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depositional History of the Namibian Mud Belt Reveals Late Holocene Weakening of the Benguela Coastal Current","authors":"Michael Kossack,&nbsp;Chloe H. Anderson,&nbsp;Nikolas Römer-Stange,&nbsp;Jürgen Titschack,&nbsp;Florian Scholz,&nbsp;Matthias Zabel","doi":"10.1029/2026GC013201","DOIUrl":"https://doi.org/10.1029/2026GC013201","url":null,"abstract":"<p>We investigate late Holocene changes in the northern Benguela Upwelling System using a multi-proxy approach on shallow shelf deposits from the Namibian mud belt. Three sediment cores characterized by organic carbon-rich, anoxic, and partly gas-bearing sediments were retrieved along a sampling transect at 23°S in August 2019. A sub-bottom profile recorded in a sampling campaign in February 2022 enabled stratigraphic correlation of the cores. As a novelty in this area to date, variations in terrigenous input patterns are reconstructed in one gravity core using major and trace element data, including rare earth elements, in a statistical provenance modeling approach. Results indicate a progressive decline in input of Orange River-derived material over the past 3800 years, attributed to a weakening of the Benguela Coastal Current (BCC). This reduction in northward directed transport energy is reflected in increasing lamination frequency observed in Computed Tomography-scan imagery and declining Zr/Al ratios toward the present. Sulfidic events observed along the Namibian coastline are interpreted as a direct consequence of the BCC weakening, since decreasing depositional energy facilitated organic matter deposition and degradation, the formation of a shallow sulfate–methane transition zone (SMTZ) and the accumulation of free sulfide and methane gas in the central mud belt area beginning around 1450 years BP. The establishment of sulfidic redox conditions in gas-bearing sediments is recorded in sedimentary Mo/U ratios exceeding modern seawater Mo/U. This study highlights the strong coupling of oceanographic changes, sedimentation processes, and biogeochemical conditions in the Benguela Upwelling System.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013201","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Distinction Between Sn-Mineralized and Sn-Barren Granites in Sn Isotopes","authors":"Cheng Xu,&nbsp;Weiqiang Li,&nbsp;Jia-Xin She,&nbsp;Qian Li,&nbsp;Kui-Dong Zhao,&nbsp;Xisheng Xu","doi":"10.1029/2026GC013102","DOIUrl":"https://doi.org/10.1029/2026GC013102","url":null,"abstract":"<p>Tin mineralization is commonly associated with highly evolved granites. However, not all highly evolved granitic rocks are mineralized with Sn. Comparative studies of Sn-fertile and Sn-barren granites can deepen our understanding of the key processes that lead to Sn enrichment in magmatic-hydrothermal systems. Here, we present Sn isotope data of two representative granitic suites in South China: the barren Xiaoxiong volcanic-intrusive complex and the Sn-mineralized Yanbei granite porphyry. The Xiaoxiong complex exhibit limited Sn isotope variation with δ^122/118Sn_3161a values ranging from 0.14 to 0.26‰ in the second-stage rocks and from 0.19 to 0.33‰ in the third-stage rocks, consistent with the baseline of the upper continental crust. In contrast, the Yanbei granite porphyry display a broad δ^122/118Sn_3161a range (0.05–0.48‰), reflecting the combined effects of fractional crystallization under relatively low oxygen fugacity conditions and subsequent fluid activity. Fractional crystallization of plagioclase with minor biotite, and Fe-Ti oxides under an oxygen fugacity of ΔFMQ∼0 can account for the initial increase in δ^122/118Sn_3161a, but only elevates Sn content by a factor of six, which is insufficient for economic mineralization. This suggests that magmatic fluid exsolution and fluid-melt interaction are crucial for substantial Sn enrichment. Modeling results show that exsolution of a small amount of fluid (2%–6%) from highly evolved melt (with Δ^122/118Sn_fluid-melt of −0.4 to −0.5‰) and that subsequent fluid-melt interaction can explain the observed low and variable δ^122/118Sn_3161a values and high Sn content in late-stage samples. This study demonstrates that Sn isotopes are effective in tracing Sn behavior during magmatic-hydrothermal evolution in granite-related systems.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing Incoming Cocos Plate Structure Outboard of the Guerrero Gap and Adjacent Segments Offshore Mexico: Implications for Along-Strike Variations in Megathrust Slip Behavior","authors":"Davis Hagemeier,&nbsp;Anne Bécel,&nbsp;Tanner Acquisto,&nbsp;Víctor M. Cruz-Atienza,&nbsp;Brandon Shuck,&nbsp;Donna J. Shillington,&nbsp;Shuoshuo Han,&nbsp;Brian Boston,&nbsp;Jorge A. Real,&nbsp;Yoshihiro Ito,&nbsp;Grace Ward","doi":"10.1029/2026GC013194","DOIUrl":"https://doi.org/10.1029/2026GC013194","url":null,"abstract":"<p>Megathrust slip behavior in subduction zones can vary along-strike, yet the mechanisms driving this variability remain uncertain. The Middle America trench offshore Mexico provides an ideal setting to investigate the structural controls on megathrust slip behavior. The Guerrero Gap (GG) segment has not hosted a large <i>M_w</i> &gt; 7 earthquake in over 115 years but accommodates long-term and short-term slow-slip events (SSEs), whereas neighboring regions regularly rupture in large earthquakes. Here, we analyze both multi-channel seismic reflection images and P-wave velocity models derived from long-offset streamer tomography to examine the structure and properties of the Cocos plate offshore the GG and its adjacent western segment to assess their role in modulating variations in slip along the megathrust. Our results indicate that sediment thickness, basement roughness, and upper oceanic crustal hydration exhibit limited along-strike variability. The upper oceanic crust is found to be a significant reservoir for pore water, while containing comparatively low amounts of structurally bound water. Bending-related faulting also referred to as flexural extension is mostly confined to ∼20 km from the trench and is characterized by relatively small fault throws compared to other subduction zones, corresponding to only a modest increase in upper-crustal hydration. Elevated fluid content is interpreted beneath a large seamount outboard of the GG. We further show that seamounts are more abundant seaward of the Guerrero and Oaxaca segments, which host long-term SSEs, suggesting a potential contribution to aseismic slip behavior. However, seamount distribution alone cannot explain along-strike variations in shallow megathrust slip behavior.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013194","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Re-Evaluating the Thermogenic Decarbonation During Large Igneous Provinces Emplacement Using Temperature-Dependent Thermal Properties","authors":"Yan Wang,&nbsp;Jianfeng Yang,&nbsp;Linpei Deng,&nbsp;Liang Zhao","doi":"10.1029/2026GC013028","DOIUrl":"https://doi.org/10.1029/2026GC013028","url":null,"abstract":"<p>Large Igneous Provinces emplacement drives mass extinctions through rapid carbon release, but the relative contributions of magmatic degassing versus thermogenic decarbonation remain debated. Here, we incorporate temperature-dependent thermal parameters into models of contact metamorphism around intruding sills. We show previous constant-parameter models overestimated inorganic decarbonation by 36%–50% due to a high-temperature thermal insulation effect, whereas estimates of organic carbon generation remain robust, with differences below 10%. Revised thermogenic carbon budgets, combined with carbon isotope mass balance constraints, reveal that thermogenic carbon accounts for less than 50% of the total carbon released across most plausible combinations of CIE magnitude, volcanic carbon release, and volcanic carbon isotope composition during the end-Permian and end-Triassic crises. This suggests that direct magmatic degassing was the dominant carbon source, underscoring the critical role of mantle-derived volatiles in shaping Earth's climate sensitivity.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}