Geochemistry Geophysics Geosystems最新文献

{"title":"Triple Oxygen and Hydrogen Isotopes of Soil Water Across Climates, Seasons, and Depths","authors":"Julia R. Kelson,&nbsp;Naomi E. Levin,&nbsp;David P. Huber,&nbsp;Lixin Jin,&nbsp;Hugo A. Gutiérrez Jurado,&nbsp;Jennifer L. Pierce","doi":"10.1029/2026GC012921","DOIUrl":"https://doi.org/10.1029/2026GC012921","url":null,"abstract":"<p>Soil waters are a central component of the terrestrial water cycle. Their δ²H, δ¹⁸O, and <i>d</i>-excess values contain rich information about hydroclimate, including the source of moisture and its evaporative history. Paleoclimate workers seek to investigate ancient hydroclimates via triple oxygen isotope geochemistry, termed Δ′¹⁷O, which is analogous to <i>d</i>-excess but can be measured in oxygen-bearing minerals in paleosols. Observations of Δ′¹⁷O in soil water across climates, seasons, and depths are needed to establish a framework for applying Δ′¹⁷O to paleohydrology. We measured the δ¹⁸O, δ²H, and Δ′¹⁷O values in soil waters (0–1 m) and precipitation in the Mojave, Great Basin, and Chihuahuan Deserts and in a temperate forest in Michigan. Evaporation drives covariation in Δ′¹⁷O and <i>d</i>-excess in soil waters. The range of Δ′¹⁷O values in soil waters (−148 to 44 per meg) spans the heretofore observed range of Δ′¹⁷O in the water cycle. The uppermost 20 cm of the soil profiles experience the greatest isotopic variation as soil water is subject to infiltration and evaporation. Each environment displays a distinct pattern in δ¹⁸O, <i>d</i>-excess, and Δ′¹⁷O of soil water. Soil water at the forested site has isotope values that closely adhere to meteoric waters. In contrast, at the dryland sites, evaporation causes soil waters to deviate from meteoric waters along site-specific trajectories. The Δ′¹⁷O patterns in soil waters adhere to expectations based on <i>d</i>-excess, strongly affirming the utility of Δ′¹⁷O in fossilized soil sediments and in modern soil waters to investigate the water cycle.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC012921","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148466790","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":"Evolution of Sulfur Concentration in the Deep Earth During the Proto-Earth Growth: First-Principles Study on the Sulfur Partitioning Between Metal and Silicate at High Pressure and Temperature","authors":"K. Itoh,&nbsp;T. Tsuchiya","doi":"10.1029/2026GC013030","DOIUrl":"https://doi.org/10.1029/2026GC013030","url":null,"abstract":"<p>Sulfur (S) is one of the promising light elements that can explain the density deficit of the core. The degree of siderophile nature of S under high pressure and temperature (<i>P</i>,<i>T</i>) is the key to estimating the S content in the core. However, a significant discrepancy between the metal-silicate partition coefficient of S extrapolated from relatively low-<i>P</i> and that measured at deep mantle <i>P</i>,<i>T</i> is identified. In this study, we calculate the partition behavior of S between liquid iron and molten silicate in a wide range of <i>P</i>,<i>T</i> conditions using the ab initio thermodynamic integration molecular dynamics approach. The results indicate that S is strongly siderophile at 0–135 GPa and 3,000–5,000K, but the partition coefficient of S (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>D</mi>\u0000 <mi>S</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${D}_{mathrm{S}}$</annotation>\u0000 </semantics></math>) markedly decreases with increasing the oxygen content in liquid iron. The pressure dependence of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>D</mi>\u0000 <mi>S</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${D}_{mathrm{S}}$</annotation>\u0000 </semantics></math> is also found to change around 20 GPa. These properties might reconcile the experimental conflicts and can be interpreted based on the atomic structures of the liquids. Using the derived <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>D</mi>\u0000 <mi>S</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${D}_{mathrm{S}}$</annotation>\u0000 </semantics></math>, we model the evolution of the S concentrations in the core and mantle during the growth of the proto-Earth. According to this model, the S concentration retained in the mantle increases as the size of the accreting planetesimals decreases and as the core becomes more oxidized. Our results further indicate that S could be a major light element in the core when the S concentration in the accreting planetesimals is larger than ∼3 mol%.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148466615","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":"Porosity and Permeability of Very Young Oceanic Crust: Implications for Hydrothermal Circulation at Mid-Ocean Ridges","authors":"Weihao Lyu,&nbsp;Michele Paulatto,&nbsp;Carl Jacquemyn,&nbsp;Matthew D. Jackson,&nbsp;Yanghua Wang","doi":"10.1029/2025GC012742","DOIUrl":"https://doi.org/10.1029/2025GC012742","url":null,"abstract":"<p>Porosity and permeability are crucial factors influencing hydrothermal flow in the oceanic crust. This paper provides a comprehensive overview of measurements and estimates of porosity and permeability. Although scientific drilling projects have yielded direct measurements of these properties, available data remain limited, particularly for very young oceanic crust (defined here as &lt;1 Ma). Typically, porosity is estimated using indirect measurements of resistivity, seismic velocity, and gravity, while permeability can be directly assessed in boreholes, and inferred from heat flow, thermal structure or derived from porosity. Porosity decreases with depth and crustal age due to mechanical compression and infilling of void spaces. However, existing equations describing these trends are inadequate for modeling hydrothermal fluid flow. To address this, we compiled published petrophysical data on the spatial distribution of porosity in the oceanic crust and developed a new descriptive model of porosity variation with depth and crustal age, validated using seismic velocity data. From this porosity model, we estimated the permeability distribution using a refined empirical equation, with fitting parameters constrained by three-dimensional numerical simulations of hydrothermal circulation near the ridge axis. Compared to previous studies, our porosity and permeability models more accurately represent observed spatio-temporal variations and match outflow temperatures. Our improved models indicate that permeability in dikes beneath extrusive lavas near the ridge axis is higher than previously expected and is a critical condition for sustaining high-temperature hydrothermal venting. This enhanced permeability may result from tectonic stress in the magmatic system, thermal cracking, or chemical dissolution driven by hydrothermal circulation.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012742","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148615171","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":"Flexural and Membrane Stresses in Doubly Curved Subducting Slabs","authors":"Gianluca Gerardi,&nbsp;Yida Li,&nbsp;Neil M. Ribe","doi":"10.1029/2026GC013018","DOIUrl":"https://doi.org/10.1029/2026GC013018","url":null,"abstract":"<p>A subducting slab is a thin doubly curved shell with a complex shape that deforms in interaction with the surrounding mantle. Such a shell can deform in two distinct ways: by in-plane stretching and shear (“membrane” deformation) and by bending and twisting (“flexural” deformation). Membrane stresses are constant across the shell, while flexural stresses vary linearly across it. Using idealized boundary-element numerical models complemented by thin-shell theory, together with a more realistic finite-element (FEM) model of the Mariana slab, we study how the stress depends on depth and on the slab's Gaussian curvature <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>G</mi>\u0000 </mrow>\u0000 <annotation> $G$</annotation>\u0000 </semantics></math> (the product of the two principal curvatures). The Mariana slab is of particular interest because it has adjacent portions with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>G</mi>\u0000 <mo>&gt;</mo>\u0000 <mn>0</mn>\u0000 </mrow>\u0000 <annotation> $G &gt; 0$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>G</mi>\u0000 <mo>&lt;</mo>\u0000 <mn>0</mn>\u0000 </mrow>\u0000 <annotation> $G&lt; 0$</annotation>\u0000 </semantics></math>. The main results are as follows: (a) the along-strike (“hoop”) membrane stress is tensile at shallow depths and compressive at greater depths when <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>G</mi>\u0000 <mo>&gt;</mo>\u0000 <mn>0</mn>\u0000 </mrow>\u0000 <annotation> $G &gt; 0$</annotation>\u0000 </semantics></math>, and the reverse when <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>G</mi>\u0000 <mo>&lt;</mo>\u0000 <mn>0</mn>\u0000 </mrow>\u0000 <annotation> $G&lt; 0$</annotation>\u0000 </semantics></math>; (b) the downdip flexural stress on the upper surface of the slab is tensile at shallow depths and compressive at greater depths. The FEM model predicts a spatial distribution of downdip membrane stress that agrees well with the downdip stress distribution inferred from centroid moment tensors of earthquakes in the Mariana slab. However, the agreement is less satisfactory for the corresponding hoop stresses.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148463132","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":"Post-Eruptive Deformation and Faulting Caused by Dike Channel Retraction, Material Drain-Back and Contraction of the 2021 Tajogaite Craters (La Palma)","authors":"Thomas R. Walter,&nbsp;Lun Ai,&nbsp;Edgar U. Zorn,&nbsp;Pablo J. González","doi":"10.1029/2026GC013008","DOIUrl":"https://doi.org/10.1029/2026GC013008","url":null,"abstract":"<p>Young scoria cones fed by dike channels or conduits may undergo rapid and substantial post-eruptive morphological modification; however, the structural controls and mechanisms governing topographic degradation remain poorly constrained. This knowledge gap limits our ability to reliably interpret topography, faults, deposits and the evolution of scoria cones. The Tajogaite eruption (La Palma, Canary Islands) produced a cratered edifice ∼180 m high by December 2021. We use multi-temporal camera and drone data sets to analyze the late- and post-eruptive structural and geomorphic evolution of the dike-fed crater row. Time-lapse camera imagery and pixel offsets document subsidence and material contraction down and toward the craters of up to ∼50 m, associated with outer crater rim fracturing and inner-wall slumping, widening the craters by ∼10%. A multi-year continuation of subsidence (∼10 m) and widening continues, as shown by drone-derived digital elevation model comparison. Structural mapping identified 430 post-eruptive fractures forming laterally extensive rim-parallel fracture belts. To gain insights into the physical processes controlling the observations, we designed analogue models of dike channel withdrawal that can reproduce the retraction structures, asymmetric fracture belt and crater widening if topography and conduit burial are considered. We propose a new conceptual model of crater retraction and morphological changes occurring at scoria cones, and discuss that normal fractures surrounding craters are not the result of the dike intrusion or eruption itself, but rather the consequence of volumetric reduction in the feeding conduit or dyke after the eruption.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148462791","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":"Linking the Tectonic Evolution of Hainan Island and Borneo Since the Paleozoic: Implication for Interaction Between the Tethyan and Paleo-Pacific Tectonic Domains in Southeast Asia","authors":"Yang Zhou,&nbsp;Pingping Li,&nbsp;Shan Li,&nbsp;Andrew Carter,&nbsp;Jonny Wu,&nbsp;Yi Yan,&nbsp;Yongjian Yao,&nbsp;Wei Liu,&nbsp;Lin Wang,&nbsp;Junzhi Liu,&nbsp;Khor Weichung,&nbsp;Rongwei Zhu,&nbsp;Zuofei Zhu,&nbsp;Qi Zhao,&nbsp;Qingsong Liu","doi":"10.1029/2025GC012837","DOIUrl":"https://doi.org/10.1029/2025GC012837","url":null,"abstract":"<p>The interaction between the Tethyan and Paleo-Pacific subduction systems in Southeast Asia since the Paleozoic is still poorly understood. Hainan Island and Borneo, located near the junction of the Tethyan and Paleo-Pacific domains, provide the critical regions for understanding the dynamic processes and interaction between the two tectonic domains. Using new and published zircon U-Pb-Hf isotopes, and the detrital zircon Eu/Eu* data, we evaluate crustal evolution and the relative crustal-thickness variations in both regions. The data sets indicate broadly synchronous intervals of reduced apparent crustal thickness inferred from Eu/Eu* at 440–410 Ma, 370–350 Ma, 270–220 Ma and 160–140 Ma, together with largely negative _<i>ε</i>Hf(<i>t</i>) values through the Paleozoic-Triassic, which characterized by the mixed mantle-derived material and older crustal components, probably associated with the Paleo-Pacific subduction. Jurassic–Cretaceous zircons from Borneo shift to mainly positive _<i>ε</i>Hf(<i>t</i>), supporting the mantle-derived material addition and a Tethyan–Paleo-Pacific double-subduction system beneath Sundaland. However, the Hainan retains mostly negative _<i>ε</i>Hf(<i>t</i>), consistent with continued Paleo-Pacific subduction and older crustal components. These results clarify how the Tethyan and Paleo-Pacific systems interacted in Southeast Asia.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012837","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148381161","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":"Osmium Isotope and Highly Siderophile Element Constraints on the Cretaceous/Paleogene Boundary in Western Pacific Pelagic Clay","authors":"Honami Sato,&nbsp;Yoichi Usui,&nbsp;Kazuhide Mimura,&nbsp;Akira Ishikawa,&nbsp;Kazutaka Yasukawa,&nbsp;Junichiro Ohta,&nbsp;Yasuhiro Kato","doi":"10.1029/2026GC013078","DOIUrl":"https://doi.org/10.1029/2026GC013078","url":null,"abstract":"<p>The Cretaceous/Paleogene (K/Pg) Chicxulub impact produced globally synchronous enrichments of highly siderophile elements (HSEs) and a pronounced decline in marine osmium isotope ratios (¹⁸⁷Os/¹⁸⁸Os), forming a key geochemical marker of the boundary. However, precise identification of the K/Pg boundary remains challenging in extensive pelagic regions dominated by deep-sea red clay, where calcareous and/or siliceous microfossils are poorly preserved. Here we identify the K/Pg boundary in a pelagic clay sequence from piston core KR13-02 PC05 recovered near Minamitorishima Island in the western Pacific Ocean using HSE concentrations and Os isotope stratigraphy, supported by ichthyolith biostratigraphy and magnetostratigraphy. A distinct Ir enrichment (up to ∼16 ppb) coincides with the most unradiogenic ¹⁸⁷Os/¹⁸⁸Os value (∼0.14) at ∼9.95 mbsf, defining a geochemical horizon consistent with the global signature of the Chicxulub impact. Polarity chrons spanning C29n–C30n and ichthyolith assemblages support the placement of the K/Pg boundary and provide a robust chronological framework. Above the boundary, ¹⁸⁷Os/¹⁸⁸Os ratios remain persistently unradiogenic over a stratigraphic interval corresponding to several hundred thousand years. This prolonged signal reflects the integrated effects of extremely low sedimentation rates, sediment reworking by bioturbation, and background extraterrestrial dust inputs. These results demonstrate that sedimentary Os isotope records in low-accumulation pelagic clay do not necessarily represent a simple archive of contemporaneous seawater composition. Instead, depositional and diagenetic processes can substantially modify post-impact isotopic signals. Our findings highlight the necessity of multi-proxy chronological control and careful geochemical screening when reconstructing oceanic responses to the K/Pg impact on microfossil-poor pelagic environments.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC013078","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148381110","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":"Occurrence and Provenance of KREEP Components in Glassy Agglutinates From Chang'e-5 Lunar Regolith","authors":"Shuai Ma,&nbsp;Zhipeng Xia,&nbsp;Bingkui Miao","doi":"10.1029/2026GC012932","DOIUrl":"https://doi.org/10.1029/2026GC012932","url":null,"abstract":"<p>This study investigates the petrogenesis of glassy agglutinates in a polished section of the Chang'e-5 lunar regolith sample CE5C0800YJYX018GP through integrated petrographic, mineralogical, and geochemical analyses of four representative particles (18GP-01 to 18GP-04). The agglutinates contain diverse lithic clasts, including basaltic fragments, anorthositic fragments, and a barred olivine-rich fragment, together with glass fragments. Mineral clasts are dominated by plagioclase, pyroxene, olivine, and ilmenite, with minor apatite, troilite, and silica phases. The glassy matrix formed primarily through impact melting of basaltic materials and shows compositions comparable to those of low-Ti mare basalts from Oceanus Procellarum. In contrast, some glass domains exhibit strong enrichment in K (K₂O up to 1.37 wt.%), P (P₂O₅ up to 4.84 wt.%), and rare earth elements (ΣREE up to 3,196.1 ppm). These enriched domains display pronounced LREE enrichment, relatively flat HREEs, and negative Eu anomalies, similar to the KREEP-rich lunar regolith from Oceanus Procellarum. Given the KREEP-poor geochemical background of the Chang'e-5 landing site, these features are most consistent with an exotic origin rather than in situ evolution of local basalts, and are best explained as material derived from the Procellarum KREEP Terrane and transported by large impact events. The micrometer-scale, heterogeneous distribution of KREEP-rich domains, together with agglutinated melt glass, and cristobalite, provides clear evidence for impact-driven transport and mixing. These observations place new constraints on lunar material redistribution, the preservation of late-stage magmatic residues, and the thermal evolution of the Moon.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC012932","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148373243","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":"Forward Image Registration for Higher Level Interpretation of Zircon Provenance Based on Combined CL, U/Pb Age, and Geochemical Data","authors":"Marco A. Acevedo Zamora,&nbsp;Balz S. Kamber,&nbsp;John T. Caulfield,&nbsp;Charlotte M. Allen,&nbsp;Justin S. Freeman","doi":"10.1029/2025GC012671","DOIUrl":"https://doi.org/10.1029/2025GC012671","url":null,"abstract":"<p>Most detrital zircon studies generate grayscale cathodoluminescence (CL) images, U/Pb dates, and variably extensive trace element concentration data. Yet the combined information contained in these data is rarely used for a higher-level interpretation of zircon provenance, which still heavily relies on comparison of sample-wide U/Pb age spectra. Here, we present a novel forward image registration software solution that allows the assembly of spatially registered data (optical microscopy and CL texture/intensity/contrast/color; Pb/U ratios/ages; and trace element concentrations/ratios), enabling zircon provenance analysis with data science. The solution is based on open-source scripts that streamline instrument software with open-source bioinformatics image analysis software and our own image processing algorithms. Equipped with this toolset, the analyst can now visualize the full range of zircon data from the registered data set within a master table. A grid display of zircon objects can be sorted by the aforementioned variables allowing intuitive visual discovery of interdependence. Using an example from a modern large river drainage system, we illustrate that new groupings and patterns can be manually defined, compared, and discovered by interacting with all available criteria. A candidate-source hypothesis is provided for a low frequency zircon population with a granitic source rock from the literature on the basis of age, chemistry, and CL attributes. Such exploration could open the path to more unique and automated sediment provenance solutions using cluster-density-diagrams.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012671","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148381109","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":"Interface Deformation, Exhumation, and Underplating: The Role of Plate Velocity Changes Throughout the Evolution of a Subduction Zone","authors":"Valeria Turino,&nbsp;Adam F. Holt,&nbsp;Derek J. Neuharth,&nbsp;Ryan K. Stoner,&nbsp;Whitney M. Behr","doi":"10.1029/2026GC012942","DOIUrl":"https://doi.org/10.1029/2026GC012942","url":null,"abstract":"<p>Exhumed metamorphic rocks yield critical insights into the mechanical, chemical, and thermal structure of the plate interface that can be used to infer exhumation pathways and their evolution throughout a subduction zone's lifetime. Metamorphosed oceanic rocks often record exhumation and underplating over relatively punctuated time periods, which appear to be linked to specific stages of subduction. Although plate velocities also vary from one stage of subduction to the next, the influence of this time dependence on exhumation and underplating remains unclear. We therefore use 2-D time-dependent subduction models to investigate how evolving plate velocities affect the timing and distribution of exhumation and underplating. By extracting plate velocities from a freely evolving subduction model and imposing them on kinematically driven models, we isolate the effects of realistic velocity variations on interface processes without the complexity of a dynamically evolving slab. We also explore the role of interface strength by varying its rheology and composition. In our models, exhumation consistently initiates during a punctuated detachment event following decreases in subduction velocity. Shallow exhumation (&lt;50 km) occurs through corner flow within the accretionary prism, while deeper underplating (&lt;140 km) involves crustal slicing and detachment along the whole interface. Weak interfaces favor continuous and voluminous exhumation, whereas strong interfaces restrict it to brief, punctuated episodes. Underplating is discontinuous throughout but increases in volume as convergence slows. These findings demonstrate that time-dependent plate velocity variations exert significant control on interface processes and naturally generate punctuated exhumation and underplating consistent with the rock record.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"27 7","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026GC012942","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148373241","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}