Geochemistry Geophysics Geosystems最新文献

{"title":"Thickening Cratonic Lithosphere by Horizontal Compression in the Presence of Surface Erosion and Sedimentation","authors":"Kristina Kublik,&nbsp;Claire A. Currie,&nbsp;D. Graham Pearson","doi":"10.1029/2025GC012194","DOIUrl":"https://doi.org/10.1029/2025GC012194","url":null,"abstract":"<p>Here we examine how lithospheric thickening is affected by active surface sedimentation and erosion in geodynamic models of craton formation—an aspect that has been neglected in previous models even though cratons may be the first landmasses to emerge above sea level. In our two-dimensional numerical models, inward horizontal velocities are imposed at the side boundaries of the model domain to induce thickening of the cratonic lithosphere by horizontal compression. Various rates of sedimentation and erosion are applied at the surface and the thickness of the lithosphere is monitored during the 50 Myr compression phase, and for 2 billion years after the imposed compression phase. In our models, surface processes act on the high-relief surface topography of the mobile belts adjacent to the cratonic nucleus. Erosion in the mobile belts during the compression alters lithosphere geodynamics, increasing the thickness of the mobile belt lithosphere to depths capable of supporting diamond growth. This enhanced thickening in the mobile belt regions limits shortening and thickening of the cratonic nucleus and the lithospheric thickness can vary by up to 15 km between models with different surface process rates.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012194","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220040","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":"Origin of Silicic Magmatism at the Katla Volcanic Complex, South Iceland","authors":"Valentin R. Troll,&nbsp;Frances M. Deegan,&nbsp;Jussi S. Heinonen,&nbsp;Caroline Svanholm,&nbsp;Chris Harris,&nbsp;Christian M. Lacasse,&nbsp;Harri Geiger,&nbsp;Agata Poganj,&nbsp;Louise Thomas,&nbsp;Malin Andersson,&nbsp;Romain Meyer,&nbsp;Thorvaldur Thordarson","doi":"10.1029/2025GC012319","DOIUrl":"https://doi.org/10.1029/2025GC012319","url":null,"abstract":"<p>The Katla volcano is a bimodal caldera complex within Iceland's basalt-dominated Eastern Volcanic Zone. To unravel the petrogenesis of silica-rich rocks from Katla, we provide new δ¹⁸O values for almost 60 basaltic, intermediate, and high-silica eruptive rocks, including a number of partially melted felsic xenoliths. The basaltic samples display a range in bulk-rock δ¹⁸O values from +4.3 to +8.5‰ (<i>n</i> = 17) and the sparse intermediate samples from +4.1 to +5.9‰ (<i>n</i> = 3). In turn, silicic rock samples and feldspar separates range from +2.7 to +6.4‰ (<i>n</i> = 38), whereas felsic xenoliths yield the lowest values from −4.9 to −2.3‰ (<i>n</i> = 4). The majority (95%) of the Katla silicic volcanics have δ¹⁸O values below typical MORB (i.e., ≤5.0‰), ruling out an origin via closed-system fractional crystallization from the basaltic magmas. We utilized the new δ¹⁸O values to model possible assimilation and fractional crystallization (AFC) scenarios. The results indicate an early stage of FC/AFC at deep- to mid-crustal levels, followed by assimilation of low-δ¹⁸O hydrothermally altered sub-volcanic materials similar to the low-δ¹⁸O felsic xenoliths at shallow crustal levels. Such a two-stage magma evolution is consistent with available geophysical and geobarometry studies at Katla, indicating mid- to deep-crustal and shallow-crustal magma domains. Importantly, mafic rocks dominantly show MORB-like δ¹⁸O values, whereas low δ¹⁸O values occur essentially in silicic rocks only. This implies that the low-δ¹⁸O values at Katla are imposed by interaction with the Icelandic crust rather than reflecting low δ¹⁸O mantle sources.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012319","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144220039","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":"Variations in Event-Bed Thickness-Frequency Distributions Near Volcanic Islands: Indicators of Varied Geological Processes","authors":"Yu-Chun Chang,&nbsp;José C. F. Kling,&nbsp;Julie C. Schindlbeck-Belo,&nbsp;Neil C. Mitchell,&nbsp;Kan-Hsi Hsiung,&nbsp;Toshiya Kanamatsu","doi":"10.1029/2025GC012185","DOIUrl":"https://doi.org/10.1029/2025GC012185","url":null,"abstract":"<p>A variety of subaerial and submarine events, including mass-wasting and volcanism, can generate sediment gravity flows and fallout deposits that are preserved in deep-water stratigraphic records. This study examines whether event beds with differing depositional and transport histories exhibit distinct thickness-frequency distributions. Analyzing over 4,500 event beds from seven drilling sites near Montserrat, the Izu Arc, the Kyushu-Palau Ridge, and Gran Canaria, the analyses explore variations in event-bed characteristics across different climatic periods, volcanic stages, and geomorphological settings. Statistical methods include characterizing thickness-frequency distributions and assessing subset similarity using <i>t</i>-tests and smoothed distribution patterns. The data-driven results indicate discernible differences where dominant geological processes vary. For example, volcanic growth stages at the Kyushu–Palau Ridge produced thicker, coarser, and more frequent event beds compared with quiescent stages. Similarly, beds from the north slope of Gran Canaria—where submarine canyons enhanced sediment delivery—were nearly twice as thick as those from the south. In contrast, indistinguishable characteristics between the rear and frontal Izu Arc subsets after 3 Ma are attributed to the development of an extensional zone supplying material to both arc sides. Comparable distributions were also observed within intervals with minimal geological differences. The reliability of this analytical approach depends on high-quality sediment recovery, as drilling-related disturbances may obscure primary depositional signals. Beyond stratigraphic characterization, the method shows broader potential for identifying the provenance of volcanic glass shards through geochemical comparisons and for evaluating the statistical compatibility of data sets from neighboring sites, ensuring sufficient sample size for robust integrated analyses.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012185","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144206900","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":"Massive Sulfide Deposition at the 13°30’N Oceanic Core Complex: Lessons Learned From Coupled Hydro-Thermo-Mechanical Modeling","authors":"Arne Glink,&nbsp;Jörg Hasenclever,&nbsp;Lars Rüpke,&nbsp;Matthias Hort,&nbsp;Sven Petersen","doi":"10.1029/2024GC012144","DOIUrl":"https://doi.org/10.1029/2024GC012144","url":null,"abstract":"<p>Young oceanic lithosphere created at mid-ocean spreading centers is subject to complex magmatic, tectonic and hydrothermal processes, especially in regions of widespread detachment faulting. This study focuses on the oceanic core complex (OCC) at the Mid Atlantic Ridge at 13°30’N. The OCC hosts the active Semenov-2 vent field and four inactive fields, including the exceptionally large Semenov-4 sulfide deposit (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math>10 Mt), which is located near the emergence of a detachment fault. To study the relationship between tectonic detachment faulting and fluid circulation we couple models for mechanical deformation and hydrothermal fluid flow. Our aim is to identify the role of the detachment in controlling location and size of sulfide deposition. First, we develop a baseline model for the tectono-magmatic evolution of the OCC using a data-based sequence for magnitude and position of axial magmatic diking. The resulting history of tectonic deformation provides a dynamic framework for modeling hydrothermal flow through porous rock, incorporating regions of active faulting and seafloor topography evolution. We then examine the impact of various fault zone permeability structures and heat sources on hydrothermal sulfide deposition. Our results show that a combination of a topographic influence, anisotropic permeability along the fault zone, transient shallow heat sources and plume interactions can efficiently reorganize the hydrothermal system. Increasing horizontal distance between heat source and vent field, however, significantly reduces hydrothermal plume stability. Modeled mass flow rates suggest that vent fields like Semenov-4 and TAG result from the focusing of fluid flow across the entire along-axis extent of the detachment structure.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC012144","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144190956","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":"Seismotectonics and Crustal Structure in the Southern Dominican Republic Offshore Margin: Implications on the Tsunami Potential","authors":"J. L. Granja-Bruña,&nbsp;J. M. Gorosabel-Araus,&nbsp;U. ten Brink,&nbsp;A. Muñoz-Martín,&nbsp;A. Rodríguez-Zurrunero,&nbsp;S. Leroy,&nbsp;A. López-Venegas,&nbsp;M. Llorente-Isidro,&nbsp;J. Macías Sánchez,&nbsp;C. Sánchez-Linares,&nbsp;A. Carbó-Gorosabel","doi":"10.1029/2024GC012092","DOIUrl":"https://doi.org/10.1029/2024GC012092","url":null,"abstract":"<p>Many coastal areas of the southern Dominican Republic experience considerable population pressure accompanied by important economic activity. The southern offshore margin is characterized by significant seismicity and active geological processes. Because of the proximity of the seismogenic and tsunamigenic areas to the coastal regions, large seismic events are likely to result in significant damage. The interpretation of seismotectonic, structural, and morphological data allowed us to characterize the tsunamigenic features. The major tectonic sources involve large shallow faults that are capable of producing earthquakes with magnitudes ranging from Mw7.0 to Mw8.1. These seismic sources could release enough energy to deform and occasionally rupture the seafloor: Muertos frontal thrust, Muertos mega-splay and the Muertos Trough fault zone. In addition, these tectonic sources show significant vertical seafloor deformation with the potential to generate tsunamis. The steeper seafloor slopes show frequent active gravitational processes, but generally have a relatively small size and their tsunamigenic potential is therefore low. However, the Complutense slump is an exception showing ≈30 km3 of mobilized material located along a large active fault. If a similar volume is rapidly mobilized in a single slope failure, it could generate a significant tsunami. The southern coast of the Dominican Republic faces a clear risk due to its proximity to potential tsunamigenic sources (30–50 km), resulting in a very short lead-time for warning. The results of this study provide basic information for future tsunami simulations that ultimately allow practical implementation of tsunami preparedness and protection, and for coastal planning and marine resource use.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC012092","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144190955","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":"Temporal Variations of the Oldest Emperor-Hawaiian Plume Signature Influenced by Interaction With Shallow Mantle Features","authors":"P. D. Kempton,&nbsp;C. Adam,&nbsp;A. D. Saunders,&nbsp;T. L. Barry","doi":"10.1029/2025GC012208","DOIUrl":"https://doi.org/10.1029/2025GC012208","url":null,"abstract":"<p>Hawaiian volcanoes &lt;∼7 Ma are believed to originate from two different portions of the deep mantle: Loa-trend volcanoes originate from within the Pacific Large Low Shear Velocity Province (LLSVP), whereas Kea-trend volcanoes tap ambient mantle adjacent to the LLSVP. To assess whether the Emperor-Hawaiian plume maintained this association throughout its history, we present new geochemical data (trace elements, Sr-Nd-Pb-Hf isotopes) and geodynamical modeling for Emperor Seamounts ranging from &gt;81 Ma (Meiji and Detroit Seamounts) to ∼50 Ma (Kōko Seamount). We show that Emperor seamounts differ from younger Hawaiian Islands in the abundance of isotopically depleted components. In ε_Hf-ε_Nd isotope space, Detroit lavas trend toward a high ε_Hf component similar to that observed in other mantle plumes (e.g., Iceland, Galápagos). This component originated deep within the mantle, possibly as a sheath surrounding the plume stem. Sampling of this component was facilitated by Detroit being ridge-proximal when it formed (∼81–76 Ma). Emperor seamounts younger than Suiko (∼68 Ma) were intraplate and located beneath progressively older, thicker lithospheres. Backtracked locations of Emperor seamounts lie up to 15° latitude north of the Pacific LLSVP. This suggests that the ancestral Emperor-Hawaiian plume was either (a) not initially associated with the Pacific LLSVP, (b) was deflected northward by shallow mantle features such that plume-ridge interactions dominated in the upper mantle or convective flow patterns modified the plume structure in the mid mantle, or (c) the edge of the Pacific LLSVP receded southward by more than 15° over the past ∼100 m.y.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012208","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144190911","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":"Sediment Depositional History and Processes for the Eurasian Basin Since 54 Ma, Arctic Ocean","authors":"Pingchuan Tan,&nbsp;Chunyang Wang,&nbsp;Fei Wang,&nbsp;Jiabiao Li","doi":"10.1029/2025GC012201","DOIUrl":"https://doi.org/10.1029/2025GC012201","url":null,"abstract":"<p>The Eurasian Basin in the Arctic Ocean, comprising the Amundsen and Nansen Basins separated by the Gakkel Ridge, has sediment deposits up to 4–5 km thick. However, its sedimentation history and processes remain poorly understood. Using 31 seismic profiles, we have estimated deposition rates for 54 Ma. From 54 to 45 Ma, the Nansen Basin averaged ∼15 cm/kyr, while the Amundsen Basin exhibited higher but variable rates (15–50 cm/kyr). From 45 to 20 Ma, the Amundsen Basin's rates decreased significantly, dropping to 6–7 cm/kyr (34–45 Ma) and ∼3.5 cm/kyr (20–34 Ma). Meanwhile, the Nansen Basin maintained higher rates (∼12 cm/kyr to ∼5 cm/kyr). After 20 Ma, sedimentation rates diverged further. The Nansen Basin stabilized at ∼5 cm/kyr and was significantly influenced by glaciation and iceberg rafting, while the Amundsen Basin continued to decline to ∼2 cm/kyr, with pelagic sediments dominated by sea-ice and iceberg rafting, and debris flows near the Lomonosov Ridge. The Nansen Basin's higher rates are likely due to its proximity to the Barents and Laptev Sea shelves, while the general declined rates across the basin are related to basin expansion, climate cooling, and reduced tectonic activity. Additionally, the Eurasian Basin's sedimentation is shaped by two phases of Siberian river activity. Before 45 Ma, the Lena and Indigirka rivers dominated, particularly near the eastern Laptev Sea Shelf. After 45 Ma, the Pyasina and Yenisey rivers became the main contributors, with significant sediment delivery through the St. Anna Trough. Sediment deposits (0.6–1 km) along the Gakkel Ridge (70°E−100°E) are also caused by these processes.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012201","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171680","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":"Constraining Solid Dynamics, Interface Rheology, and Slab Hydration in the Hikurangi Subduction Zone Using 3-Dimensional Fully Dynamic Models","authors":"D. Douglas,&nbsp;J. Naliboff,&nbsp;M. R. T. Fraters,&nbsp;J. Dannberg,&nbsp;D. Eberhart-Phillips,&nbsp;S. Ellis","doi":"10.1029/2024GC011824","DOIUrl":"https://doi.org/10.1029/2024GC011824","url":null,"abstract":"<p>Simulating present-day solid Earth deformation and volatile cycling requires integrating diverse geophysical data sets and advanced numerical techniques to model complex multiphysics processes at high resolutions. Subduction zone modeling is particularly challenging due to the large geographic extent, localized deformation zones, and the strong feedbacks between reactive fluid transport and solid deformation. Here, we develop new workflows for simulating 3-dimensional thermal-mechanical subduction and patterns of volatile dehydration at convergent margins, adaptable to include reactive fluid transport. We apply these workflows to the Hikurangi margin, where recent geophysical investigations have offered unprecedented insight into the structure and processes coupling fluid transport and solid deformation across broad spatiotemporal scales. Geophysical data sets constraining the downgoing and overriding plate structure are collated with the Geodynamic World Builder, which provides the initial conditions for forward simulations using the open-source geodynamic modeling software code ASPECT. We systematically examine how plate interface rheology and hydration of the downgoing plate and upper mantle influence Pacific–Australian convergence and seismic anisotropy. Models prescribing a plate boundary viscosity of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>5</mn>\u0000 <mo>×</mo>\u0000 <mn>1</mn>\u0000 <msup>\u0000 <mn>0</mn>\u0000 <mn>20</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $5times 1{0}^{20}$</annotation>\u0000 </semantics></math> Pa s best reproduce observed plate velocities, and changing the configuration of the Pacific–Australia plate boundary directly influences the modeled plate motions. Models considering hydrated olivine fabrics best reproduce observations of seismic anisotropy. Predicted patterns of slab dehydration and mantle melting correlate well with observations of seismic attenuation and arc volcanism. These results suggest that hydration-related rheological heterogeneity and related fluid weakening may strongly influence slab dynamics. Future investigations integrating coupled fluid transport and global mantle flow will provide insight into the feedbacks between subduction dynamics, fluid pathways, and arc volcanism.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC011824","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144171954","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 First-Order Crustal Structure and Basin Architecture of the Canadian Arctic Margin","authors":"Randell Stephenson,&nbsp;Goodluck Anudu","doi":"10.1029/2025GC012196","DOIUrl":"https://doi.org/10.1029/2025GC012196","url":null,"abstract":"<p>First-order sedimentary isopach and depth-to-Moho maps have been produced for the first time along the Canadian Arctic margin from legacy seismic profiles, calibrated with two-dimensional gravity and magnetic modeling and augmented by some younger passive seismic and exploration seismic data. These maps show margin-scale structural patterns that can be interpreted in terms of fundamental tectonic processes of lithosphere deformation. The Canadian Arctic margin from the Beaufort Sea to Sever Spur, but not beyond it, is a typical passive continental margin along the Canada Basin ocean. However, beyond Sever Spur through to the Lincoln Shelf, the margin comprises a narrow linear sedimentary basin overlying an axis of crustal thinning embedded within continental lithosphere. This basin formed by intracontinental (trans)extension at least in part after the main HALIP magmatic events that helped build Alpha Ridge on its northern margin. This segment of the margin has a tectonic affinity more facing the Late Cretaceous and Cenozoic North Atlantic-Baffin Bay-Arctic extensional regime rather than the earlier Canada Basin extensional regime. These interpretations, which together provide a “Canadian” boundary condition on models of Amerasia Basin origin and evolution, are clearly speculative given the resolution of the available geophysical data. They are presented here, nevertheless, accompanied by a thorough overview of pertinent recent literature, with the aim of helping to prompt and inform further debate about the tectonic history of the Arctic Ocean.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025GC012196","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148387","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":"Eruption, Emplacement and Internal Architecture of Massive and Super-Massive Inflated Submarine Basalt Lava Flows, Walvis Ridge Hotspot Track, IODP Expeditions 391/397T","authors":"John W. Shervais,&nbsp;Jesse L. Scholpp,&nbsp;Mike Widdowson,&nbsp;Wendy R. Nelson,&nbsp;Katherine E. Potter,&nbsp;Stephan Homrighausen,&nbsp;Drew White,&nbsp;David Buchs,&nbsp;Daniel E. Heaton,&nbsp;Aaron Avery,&nbsp;Rajneesh Bhutani,&nbsp;Robert A. Duncan,&nbsp;Cornelia Class,&nbsp;Mbili Tshiningayamwe,&nbsp;Yusuke Kubota,&nbsp;Xiao-Jun Wang,&nbsp;Tao Wu,&nbsp;William W. Sager,&nbsp;Kaj Hoernle,&nbsp;Tobias Höfig","doi":"10.1029/2024GC012145","DOIUrl":"https://doi.org/10.1029/2024GC012145","url":null,"abstract":"<p>Massive submarine basalt flows were sampled at five sites on the Tristan-Gough-Walvis hotspot track in the South Atlantic by International Oceanic Discovery Program Expeditions 391/397T, where the plume was interacting with a mid-ocean ridge, a setting similar to that the of modern Iceland. High resolution XRF core scans document significant internal chemical variations with depth in these flows. Some of this reflects basal olivine accumulation. However, some examples have “scallop-shaped” patterns that are interpreted to represent influxes of new magma during flow lobe inflation with successive lava injections focused toward the base of the flow unit. Olivine concentration in the deeper parts of the flow is interpreted to reflect top-down tapping of a vertically zoned magma chamber, with the upper part of the chamber erupting first, and successive eruptive pulses tapping progressively deeper levels of the stratified chamber. The occurrence of massive submarine lava flows requires high eruptive fluxes relative to pillow lava formation. Propagation of these massive flows is favored by (a) high sea water confining pressures, which inhibit vesiculation and keep effective viscosity low and dissolved volatile content high, and (b) chill zones and thick viscoelastic crusts of quenched lava on the flow tops, which effectively insulate the flow interior from ambient temperatures. The formation of a thin film of super-heated steam on the upper flow surface may similarly enhance the insulation. Evidence suggests that similar massive flows on the seafloor may extend many kilometers from their vents.</p>","PeriodicalId":50422,"journal":{"name":"Geochemistry Geophysics Geosystems","volume":"26 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024GC012145","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148389","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}