Earth and Planetary Science Letters最新文献

{"title":"Mercury has multiple, superposed global tectonic patterns","authors":"Christian Klimczak ,&nbsp;Kelsey T. Crane ,&nbsp;Paul K. Byrne","doi":"10.1016/j.epsl.2025.119331","DOIUrl":"10.1016/j.epsl.2025.119331","url":null,"abstract":"<div><div>There is a long tradition in studying tectonic landforms on Mercury, as it hosts myriad structures accommodating both shortening and extension. These landforms have been extensively studied in terms of size, distribution, and age, and many tectonic maps have been produced. The orientations of fault-related landforms were previously studied for subsets of structures, but a detailed global investigation of orientations for all tectonic landforms on Mercury has yet to be carried out. Variations in orientations of tectonic structures across the globe can provide insights into the tectonic processes that formed them. We compile a global tectonic map that contains 18,541 structures specified as shortening landforms, extensional landforms, or troughs. We process the map data to extract fault orientations in three different geographic configurations with radial and concentric bins around the rotational poles, the Caloris basin, and the hot poles. In each of these three representations, we find systematic tectonic patterns that, taken together, show multiple, superposed preferred orientations of faults. In particular, systematic thrust fault orientations radial and concentric to the Caloris basin are detected on the hemispheric scale, revealing an enormous impact damage zone where fractures were reactivated by later tectonic processes. Furthermore, faults display systematic orientations around the hot poles, showing that tectonic processes or lithospheric strength and thickness variations arising from Mercury's spin–orbit resonance with the Sun have played a role in its tectonic history.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119331"},"PeriodicalIF":4.8,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684605","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":"2023–2024 inflation-deflation cycles at Svartsengi and repeated dike injections and eruptions at the Sundhnúkur crater row, Reykjanes Peninsula, Iceland","authors":"Michelle Parks ,&nbsp;Vincent Drouin ,&nbsp;Freysteinn Sigmundsson ,&nbsp;Ásta R. Hjartardóttir ,&nbsp;Halldór Geirsson ,&nbsp;Gro B.M. Pedersen ,&nbsp;Joaquin M.C. Belart ,&nbsp;Sara Barsotti ,&nbsp;Chiara Lanzi ,&nbsp;Kristín Vogfjörd ,&nbsp;Andrew Hooper ,&nbsp;Benedikt Ófeigsson ,&nbsp;Sigrún Hreinsdóttir ,&nbsp;Einar Bessi Gestsson ,&nbsp;Ragnar H. Þrastarson ,&nbsp;Páll Einarsson ,&nbsp;Valentyn Tolpekin ,&nbsp;Drew Rotheram-Clarke ,&nbsp;Sydney R. Gunnarsson ,&nbsp;Birgir V. Óskarsson ,&nbsp;Virginie Pinel","doi":"10.1016/j.epsl.2025.119324","DOIUrl":"10.1016/j.epsl.2025.119324","url":null,"abstract":"<div><div>Series of inflation-deflation cycles have occurred during 2020–2024 in the center of the Svartsengi volcanic system, SW-Iceland. Since 27 October 2023, continuous inflation has been interrupted by deflation periods when nine dike injections and seven eruptions have occurred from 10 November 2023 to 8 December 2024 at the Sundhnúkur crater row and its extension. Extensive observations of ground deformation using GNSS (Global Navigation Satellite System) geodesy and interferometric analysis of synthetic aperture satellite (InSAR) images is here used to improve understanding of the dynamics of magma accumulation and transfer, both prior to and during repeated rifting events. Joint inversions of the GNSS and InSAR data, considering a deformation source within a uniform elastic half-space, infer pressure changes at about 4–5 km depth near the regional brittle-ductile boundary, with inflow causing volume increase rates of 2.4–9 m³/s. Geodetic modelling using GNSS has been undertaken in near real-time throughout the events, using deformation sources in fixed locations inferred in earlier joint inversions. The deflation periods began rapidly when a dike propagated from the eastern edge of the magma accumulation area. The estimated volume of dikes is in the range (1–133) × 10⁶ m³, with the first event being by far the largest and longest (∼15 km). Geodetic observations have contributed to success in forecasting diking/eruption onset in the medium and short term, using the expectation that a correlation exists between volume loss in the magma domain during a deflation event and subsequent volume recharge to the system before the next event is triggered.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119324"},"PeriodicalIF":4.8,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684694","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":"Polybaric heterogeneous mush zones: From deep to shallow beneath the ultraslow-spreading Southwest Indian Ridge","authors":"Xiang Cui ,&nbsp;Huaiyang Zhou ,&nbsp;J. Koepke ,&nbsp;Qiang Ma","doi":"10.1016/j.epsl.2025.119325","DOIUrl":"10.1016/j.epsl.2025.119325","url":null,"abstract":"<div><div>The formation and evolution of the oceanic lithosphere are controlled by complex magmatic processes that remain subjects of ongoing research. Studies on Plagioclase Ultraphyric Basalt (PUB) have greatly expanded our understanding of these processes over the past two decades. In this study, we report a novel type of PUB sampled from the ultraslow-spreading Southwest Indian Ridge (SWIR), revealing two distinct mineral assemblages that coexist within individual samples. Group 1 minerals, dominated by high-anorthite (An) plagioclase macrocrysts with core An values up to 86 and high-Mg olivine with core Fo (molar Mg/(Mg+Fe) × 100) values up to 88, are characterized by cotectic crystallization. They represent deep, anorthositic mush zones that have undergone multiple magma replenishments. In contrast, Group 2 minerals, consisting of clinopyroxene oikocrysts and plagioclase chadacrysts, display features of fractional crystallization from shallower gabbroic mush zones. The broad range of ⁸⁷Sr/⁸⁶Sr ratios in Group 1 plagioclase macrocrysts (0.70280–0.70375) and Group 2 plagioclase chadacrysts (0.70285–0.70388), coupled with a narrower isotopic range in matrix plagioclase laths (0.70308–0.70384), suggests that magma diversity was well preserved within these crystal mushes. Moreover, significant magma mixing from variable sources occurred at mid-crustal levels. These findings illustrate the presence of polybaric, heterogeneous mush zones, with slow crystallization occurring at various depths beneath the SWIR. This study highlights the intricate interplay among multiple magma sources, replenishment events, and crystallization environments, providing new insights into the formation and variability of the oceanic crust at ultraslow-spreading ridges.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119325"},"PeriodicalIF":4.8,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684689","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":"Microwave thermophysical properties of surface deposits in CE-6 landing region and its potential implications for analyzing the returned samples","authors":"Wenqing Chang ,&nbsp;Zhiguo Meng ,&nbsp;Yi Xu ,&nbsp;Xiaoping Zhang ,&nbsp;Roberto Bugiolacchi ,&nbsp;Long Xiao ,&nbsp;Jinsong Ping ,&nbsp;Hongbo Zhang ,&nbsp;Yuanzhi Zhang","doi":"10.1016/j.epsl.2025.119326","DOIUrl":"10.1016/j.epsl.2025.119326","url":null,"abstract":"<div><div>The Apollo basin, situated on the northeastern edge of the South Pole-Aitken (SPA) basin, is the sampling area for the Chang'e -6 (CE-6) mission. In this study, we investigated the microwave thermophysical properties of surface deposits in the region by comparing brightness temperature (TB) and TB difference (dTB) maps derived from CE-2 Microwave Radiometer data combined with topography, chemical elements, and Moon Mineralogy Mapper products. The main results are as follows. (1) High dTB anomaly: A significant high dTB anomaly is identified near the CE-6 landing region, characterized by the highest FeO and TiO₂ contents estimated from the small-fresh craters; (2) Basaltic Volcanism: High dTB anomaly is proposed as a new basaltic unit in late stage of mare infill, and, by combining derived ages and geomorphology, we provide a new perspective on the basaltic volcanism with four episodes of magma infill in the CE-6 landing region; (3) Thermophysical Parameters: The high dTB anomaly indicates the potential importance of analyzing the returned CE-6 samples to enhance our understanding of the Moon's surface deposits using the passive microwave remote sensing data.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119326"},"PeriodicalIF":4.8,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684692","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":"Intraoceanic active rifting revealed by deep seismic reflection imaging in the southern Bay of Bengal, northeastern Indian Ocean","authors":"Luning Shang ,&nbsp;Gang Hu ,&nbsp;Thomas P. Ferrand ,&nbsp;Jun Pan ,&nbsp;Chuansheng Yang","doi":"10.1016/j.epsl.2025.119328","DOIUrl":"10.1016/j.epsl.2025.119328","url":null,"abstract":"<div><div>Oceanic domains form via the break-up of the continental lithosphere resulting from extensional tectonic processes that eventually create passive margins. Whether active rifting and subsequent volcanic break-up occur within the oceanic lithosphere remains ambiguous. New seismic reflection data from the southern Bay of Bengal, where multiple mantle plumes were active during the late Cretaceous, provide visual evidence for resolving this issue. The studied seismic profile reveals an ∼300-km-wide anomalous crustal domain characterized by basement highs, irregular Moho depth fluctuations, and a thick pile of well-organized upper crustal dipping reflections. These features resemble those of volcanic passive margins, i.e., stacked volcanoclastic layers, seaward-dipping reflectors, underplating and failed rifting centers. Here, we document a similar setting within an intraoceanic domain, which is consistent with the active rifting model, with an excess magma supply presumably associated with active mantle upwelling. The structures described in the present study require a multistage dynamic process during local impingement of the northward-drifting Indian oceanic lithosphere by mantle upwelling, with a transition from thermal doming, intense volcanic eruptions and magmatic underplating, to lithospheric extension and necking, and finally to an incipient but failed rift. The volcanism initiated at ∼84–85 Ma, and volcanics were emplaced on young oceanic lithosphere with an age of ∼7–8 Ma. The active mantle upwelling that promoted the intraoceanic rifting was likely driven by a weak or pulsed branch of the Kerguelen Plume, which is also involved in producing the Ninety-East Ridge. These findings help further understand the processes dominating lithospheric breakup and extend some concepts seaward from passive margins to the interior of the oceanic lithospheric domain.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119328"},"PeriodicalIF":4.8,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684693","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":"Moho depth (crustal thickness) variations under the northeastern midcontinent of North America, based on H-κ−c receiver-function analysis","authors":"Hongyu Xiao ,&nbsp;Stephen Marshak ,&nbsp;Michael DeLucia ,&nbsp;Xiaodong Song","doi":"10.1016/j.epsl.2025.119289","DOIUrl":"10.1016/j.epsl.2025.119289","url":null,"abstract":"<div><div>Previous studies of crustal thickness variation in the cratonic platform and bordering foreland basin of the USA Midcontinent emphasize that Moho relief exceeds topographic relief by an order of magnitude and exceeds structural relief of the Great Unconformity (the Phanerozoic-Precambrian contact) by a factor of 2 to 3. Consequently, the Moho displays significant local slopes. Unfortunately, traditional receiver-function analysis of depth to the Moho can lead to inaccurate results when applied to steeply sloping Moho. Therefore, to decrease measurement uncertainty due to slopes, we applied the recently developed H-κ-c receiver-function method (Li et al., 2018) to the northern and part of the eastern Midcontinent of the United States to produce a higher-resolution map of Moho-depth (i.e., crustal thickness) variation. Results for the central Midcontinent (including the Ozark Plateau and southern Illinois Basin) were reported in Xiao et al. (2022). Here, we extend our coverage eastward and northward, across the Michigan Basin, Grenville front, and western Appalachian Basin.</div><div>Our results emphasize that crustal thickness varies by almost 13 km in a region of North America where land-surface varies by less than 0.5 km and where relief of the Great Unconformity varies by a maximum of 7.5 km. In contrast to contemporary orogenic belts, crustal thickness does not correlate directly with either land-surface elevation or with sedimentary cover thickness (i.e., depth to the Great Unconformity). For example, the thickest crust of the study area occurs in the southwestern Illinois Basin, where land surface elevation is about 150 m, and the thinnest crust occurs in north central Indiana, where land-surface elevation is 250 m. There is a rough correspondence between crustal thickness and epeirogenic structures. In general, thinner crust underlies domes and arches, whereas thicker crust underlies basins, but there are exceptions. For example, while crust is relatively thin beneath the Kankakee and Cincinnati Arches, it is relatively thick beneath the Findlay Arch and the Wisconsin Arch, crust beneath the Michigan basin, overall, is thinner than that of the Illinois or Appalachian basins, and crust beneath the Canadian Shield is thinner than that beneath the cratonic platform. Notably, the Moho beneath the Canadian Shield and beneath the cratonic platform west of the Grenville front, displays roughly periodic long-wavelength north-south trending undulations. These undulations do not coincide with Precambrian tectonic fabrics or crustal boundaries, hinting that they developed after crustal assembly and could instead reflect variable degrees of thinning, underplating, or crustal delamination during failed Proterozoic rifting, or perhaps of crustal buckling associated with the Grenville collision.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119289"},"PeriodicalIF":4.8,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684690","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":"Dual clumped isotopes reveal an out-of-equilibrium state in shallow-water carbonate sediments on Great Bahama Bank","authors":"Chaojin Lu ,&nbsp;Megan E. Moore ,&nbsp;Peter K. Swart","doi":"10.1016/j.epsl.2025.119322","DOIUrl":"10.1016/j.epsl.2025.119322","url":null,"abstract":"<div><div>While non-skeletal carbonate grains and muds precipitated on shallow-water platforms have been widely used to reconstruct past ocean temperatures and chemistry, the question remains as to what degree the geochemical signatures of carbonate sediments are in equilibrium with their original environments. To evaluate the extent of equilibrium, we have applied the dual clumped isotope proxy (Δ₄₇ and Δ₄₈) to surface sediments (aragonite &gt; 90 %, <em>n</em> = 150) ranging from mudstones (&lt; 63 μm) to non-skeletal grainstones from the Great Bahama Bank. While there is no statistical difference in the mean Δ₄₇ values of the various facies, there are very large ranges of Δ₄₇ values within each type (∼ 0.1 ‰) equivalent to a temperature uncertainty of 25 °C. Our Δ₄₈ data reveals an out-of-equilibrium state where the muddy sediments have more positive values than the equilibrium, while the grainy facies are more negative. The positive Δ₄₈ disequilibrium in the muds is proposed to be a result of the photosynthetic removal of CO₂ caused by the activity of cyanobacteria turns promotes the precipitation of calcium carbonate in the water column (whitings area). In contrast, the grainstones, that are mainly composed of peloids, show a negative Δ₄₈ disequilibrium resulting from the CO₂ absorption by a complex mixture of biogeochemical processes. Our findings highlight the importance of kinetic processes in shaping non-skeletal carbonate factories and defining their geochemistry.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119322"},"PeriodicalIF":4.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143684691","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":"Limited water contents of wadsleyite and ringwoodite coexisting with hydrous minerals in cold subducting slabs","authors":"Takayuki Ishii ,&nbsp;Jintao Zhu ,&nbsp;Eiji Ohtani","doi":"10.1016/j.epsl.2025.119310","DOIUrl":"10.1016/j.epsl.2025.119310","url":null,"abstract":"<div><div>How water is distributed in a subducting slab is essential to understand water transport into the deep mantle and mechanisms of deep-focus earthquakes and slab deformation around the 660-km discontinuity. A recent experimental study demonstrated that water contents of olivine and wadsleyite coexisting with hydrous phase A is limited at upper mantle pressures, suggesting strong water partitioning to the hydrous phase. However, water distribution between nominally anhydrous and hydrous minerals at the deeper mantle is not investigated in detail. We determined water contents in wadsleyite and ringwoodite coexisting with hydrous phases down to transition-zone depths along cold slab temperatures. Wadsleyite coexisting with hydrous phase A has ∼200 ppm water at 14–16 GPa and 800 °C. At 21 GPa, ringwoodite coexisting with superhydrous phase B has 8–13 ppm water at 800 °C and 46 ppm at 900 °C. Thus, olivine and its high-pressure polymorphs are kinetically dry along cold slab core conditions even in a wet subducting slab. Slab deformation and stagnation around 660 km depth can be caused by grain-size reduction due to phase transitions of dry olivine and the presence of rheologically weak hydrous phases. The deepest earthquakes below 660 km depth can be caused by dehydration of hydrous phases.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119310"},"PeriodicalIF":4.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Zebra textures in fault-controlled, hydrothermal dolomite bodies: Coupled mechanisms of replacement, deformation, and cementation","authors":"Cole A. McCormick ,&nbsp;Ernest H. Rutter ,&nbsp;Hilary Corlett ,&nbsp;Matthew Steele-MacInnis ,&nbsp;Eivind Block Vagle ,&nbsp;Fiona Whitaker ,&nbsp;Cathy Hollis","doi":"10.1016/j.epsl.2025.119274","DOIUrl":"10.1016/j.epsl.2025.119274","url":null,"abstract":"<div><div>Fault-controlled, hydrothermal dolomitization typically involves the interaction of high pressure (P), high temperature (T) fluids with the surrounding host-rock. A striking feature of hydrothermal dolomite bodies is the pattern development and periodicity of zebra textures, whereby alternating units of replacement dolomite (RD) and saddle dolomite (SD) form symmetrical RD-SD/SD-RD patterns. Zebra textures are often considered to be diagnostic of these elevated P/T conditions, but the roles of mechanical deformation and the localization of strain during dolomitization have received limited attention. Here we evaluate the effect of P/T perturbations on the genesis of zebra textures, alongside how strain-hardening mechanisms promote their characteristic pattern development. Published fluid inclusion homogenization and carbonate clumped isotope temperatures were compiled from the literature and the offset between these data were used as a geobarometer. Based on these pore-fluid pressures, a series of rock deformation experiments were conducted to reproduce zebra textures in the laboratory. Cylindrical rock samples were held in an annealed copper jacket and deformed in axisymmetric extension. As the rock underwent tensile failure, the copper jacket locally deformed by intracrystalline plasticity, strain-hardened, and stabilized each opening-mode fracture. As a result, a succession of closely spaced fractures formed along the length of the sample. In natural geological settings, an analogous process is inferred, whereby dilatancy hardening, precipitation hardening, and the stress shadow effect promote the rhythmicity that is a defining feature of zebra textures. Lastly, the effects of P/T perturbations on the solubility of dolomite, for a range of different fluid compositions, were evaluated using the Pitzer aqueous model in PHREEQC. This interdisciplinary study presents novel insights into the geomechanical and hydrochemical interaction between metasomatic fluids and carbonate rocks, which are of critical importance to our understanding of carbonate-hosted ore deposits in sedimentary basins worldwide.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119274"},"PeriodicalIF":4.8,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Reexamination and reidentification of ocean oxygenation event in the wake of the Marinoan glaciation","authors":"Run Li ,&nbsp;Xiqiang Zhou ,&nbsp;Chuan Guo ,&nbsp;Taiyu Huang ,&nbsp;Zhenfei Wang ,&nbsp;Kang-Jun Huang ,&nbsp;Peng Peng ,&nbsp;Xiangli Wang ,&nbsp;Tongxuan Du ,&nbsp;Dingshuai Xue ,&nbsp;Yanhong Liu","doi":"10.1016/j.epsl.2025.119312","DOIUrl":"10.1016/j.epsl.2025.119312","url":null,"abstract":"<div><div>The earliest Ediacaran oceanic oxygenation event in the wake of the Marinoan glaciation defined as OOE-A (∼635–632 Ma) constitutes an integral component of the Neoproterozoic Oxygenation Event. It was largely identified based on high enrichments of redox-sensitive elements (RSEs) in the basal Ediacaran Doushantuo Formation in South China, but this proposal has been challenged on a global scale. Here, we reexamine the purported OOE-A through an integrative study of correlative successions across the shelf-to-basin transect in South China, along with records from other continents. Sedimentary and geochemical evidence, including iron speciation, RSE concentrations, organic carbon isotopes, and pyrite sulfur isotopes, collectively suggest an oxic shelf and an anoxic (intermittently euxinic) basin with a fluctuating chemocline around the upper slope environment in South China. Importantly, a diffusion-reaction model integrating sedimentation rates and authigenic RSE concentrations suggests that the discrepancies in RSE enrichment levels between the basal Ediacaran black shales of South China and northwestern Canada can be reconciled if seawater Mo and U concentrations were only 0.5–3 % and 1.5–6 % of their modern values, respectively. This finding contradicts the traditional viewpoint of the expansion of seawater RSE reservoirs in response to a widely oxygenated ocean, while emphasizing a non-negligible role of slow sedimentation rate in driving authigenic RSE enrichments in anoxic marine facies locally. From spatial and temporal perspectives, this study further refines the magnitude of the OOE-A in South China, characterizing it as a short-lived oxygenated shelf environment in a redox-stratified ocean. The reexamination of OOE-A offers new insights into understanding other documented oceanic oxygenation events, as well as the cause-and-effect relationship between marine oxygenation and biological evolution during the Neoproterozoic Oxygenation Event.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"658 ","pages":"Article 119312"},"PeriodicalIF":4.8,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642461","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}