Earth and Planetary Science Letters最新文献

{"title":"Elemental-organic geochemical evidence for the lacustrine metalimnetic oxygen minimum dynamics in the Mid-Late Triassic Chang 7 shales","authors":"Leibo Bian ,&nbsp;Xiaomei Wang ,&nbsp;Anthony Chappaz ,&nbsp;Zhongyu Xiong ,&nbsp;Mingze Ye ,&nbsp;Shuichang Zhang ,&nbsp;Wenzhi Zhao","doi":"10.1016/j.epsl.2024.119153","DOIUrl":"10.1016/j.epsl.2024.119153","url":null,"abstract":"<div><div>The Middle-Late Triassic Ordos Basin has gained increasing attention due to its significance in recording the earliest known recovery-radiation of terrestrial aquatic ecosystems following the Permian-Triassic mass extinction (PTME) and its abundant non-renewable resources. Despite numerous attempts to elucidate the mechanisms for high organic carbon burial, the pattern of carbon cycle and its associated environmental variations remain largely unknown, probably ascribed to multi-periodic deposition of volcanic ashes and complex lacustrine depositional architectures. Herein, we reconstructed environmental variations within basinal and global contexts and identified the formation of metalimnetic oxygen minimum area in paleo-lacustrine environments. Our results demonstrate a shift of oxygen-deficient and organic matter hyper-enriched areas from the central basin in the lower part of Chang 7–3 (interval I) towards the periphery in the upper part (interval II). This transition is ascribed to enhanced weathering intensity but weakened volcanic activity, which is contemporaneous with terrestrial bio-evolution across the Mid-Late Triassic boundary. In addition, the contemporary variations in carbon isotopes and relatively sea and lacustrine levels around the Paleo-Tethys Ocean, along with the rare occurrence of high redox metal abundances in lacustrine environments, indicate a (intermittent) water connection between the Ordos Basin and Paleo-Tethys Ocean during the latest Middle Triassic to early Late Triassic. We hypothesize that mild to moderate volcanic activity induced genetic disturbance and stimulated bio-irradiation in the late Ladinian. In contrast, intensified weathering resulted in biological proliferation but also transiently elevated morality in the early Carnian, which appears to be the prelude of spectacular Triassic terrestrial radiation that dominates modern ecosystems.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119153"},"PeriodicalIF":4.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759275","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":"Inverted metamorphic gradient in the Zanhuang nappe/thrust system, north China indicates large-scale thrust stacking in an Archean Orogen","authors":"Yating Zhong ,&nbsp;Kurt Stüwe ,&nbsp;Timothy Kusky ,&nbsp;Christoph A. Hauzenberger ,&nbsp;Simon Schorn ,&nbsp;Lu Wang","doi":"10.1016/j.epsl.2024.119121","DOIUrl":"10.1016/j.epsl.2024.119121","url":null,"abstract":"<div><div>We report a dramatic inverted metamorphic gradient across an Archean suture zone in the North China craton. The upper plate of the suture experienced metamorphic conditions of 650–700 °C/7–11 kbar, whereas the lower plate experienced temperatures of 500–600 °C, and pressures of 4-6 kbar, rising slightly in the frontal thrusts of the orogen. Importantly, we show that metamorphic conditions drop from 11 kbar/700 °C to 4 kbar/500 °C over a mere 1 km across-strike, representing a depth difference of almost 20 km across the frontal thrust fault. <em>P-T</em> trajectories derived from the upper plate record decompression, whereas those from the lower plate record a prograde path with increasing temperature. We show that the inverted metamorphic gradient formed during emplacement of thrust sheets during an Archean arc/continent collision, accommodating horizontal transport of at least hundreds of kilometers 2.5 billion years ago. Peclet number analysis shows that the inverted gradient formed with a thrusting rate of ∼ 30 mm/yr, consistent with modern analogues. This finding enhances our understanding of Archean tectonics and highlights similar convergence rates and thermal structure of orogens between Archean and modern examples.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119121"},"PeriodicalIF":4.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757503","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":"Subduction-stalled plume tail triggers Tarim large igneous province","authors":"Kai Wang ,&nbsp;Keqing Li ,&nbsp;Keda Cai ,&nbsp;Xiangsong Wang ,&nbsp;Jiashun Hu","doi":"10.1016/j.epsl.2024.119150","DOIUrl":"10.1016/j.epsl.2024.119150","url":null,"abstract":"<div><div>Cold slab subduction and hot plume burst are generally envisaged as independent triggers for convergent margin and intraplate magmatisms, respectively. However, descending oceanic plates occasionally encounter ascending mantle plumes, leading to contrasting hypotheses that plumes interrupt subduction processes and/or slabs choke plume pathways. This study used 2-D numerical simulation to reproduce a Paleozoic scenario in Central Asia where a subduction-induced plume head is invoked to interpret the formation of the Tarim large igneous province (LIP). The model assumes a long-lived mantle plume beneath the South Tianshan oceanic plate adjacent to the trench. As subduction initiated, plume materials spread first under the moving oceanic lithosphere, which developed a sequence of seamounts. Subsequently, the continual subduction drove a strong downwelling flow that stalled or restricted plume ascent in the upper mantle and caused the accumulation of hot materials in the uppermost lower mantle. Ultimately, the slab break-off after collision provided an opening pathway allowing for the accumulated hot materials to reach the surface, resulting in the development of a concurrent plume head and the formation of LIP on the overriding Tarim craton. Bending and rollover of the subducted oceanic lithosphere beneath an implemented stationary trench may contribute slab components to the LIP source, which can reasonably explain the slab-like geochemical fingerprints of basaltic rocks. Our work offers a tentative interpretation for the paradox that seamount formation preceded the LIP eruption in Tianshan and highlights possible slab effects, where subduction can stall the plume tail, causing heat accumulation that triggers a LIP.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119150"},"PeriodicalIF":4.8,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745973","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":"Diffusion of Sr and Ba in plagioclase: Composition and silica activity dependencies, and application to volcanic rocks","authors":"Thomas Grocolas ,&nbsp;Elias M. Bloch ,&nbsp;Anne-Sophie Bouvier ,&nbsp;Othmar Müntener","doi":"10.1016/j.epsl.2024.119141","DOIUrl":"10.1016/j.epsl.2024.119141","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Strontium and barium diffusion chronometry in plagioclase is routinely applied to mafic and felsic magmatic systems. This technique can be used to determine the timescales of magma reservoir assembly and the cooling rates of plutons and volcanic rocks, which has emerged as a useful method to assess volcanic hazards. Here we report diffusion experiments that aim to constrain the diffusivities of Sr and Ba in oligoclase and labradorite at 1 atm pressure, between 900 and 1,200 °C, and assessing diffusion in different crystallographic orientations. In all of the reported experiments, silica activity (&lt;em&gt;a&lt;/em&gt;SiO&lt;sub&gt;2&lt;/sub&gt;) is buffered by varying stable phase assemblages in the diffusant source powder. The experimental products were analysed by secondary ion mass spectrometry (SIMS) depth profiling and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) line scanning. There is no resolvable dependence of Sr and Ba diffusion in plagioclase upon &lt;em&gt;a&lt;/em&gt;SiO&lt;sub&gt;2&lt;/sub&gt; or crystal orientation. However, Sr and Ba diffusivities are found to vary as functions of the plagioclase anorthite content. As such, we parameterise the diffusivity of Sr and Ba in plagioclase as a function of temperature and anorthite content as follows:&lt;span&gt;&lt;span&gt;&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;log&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mtext&gt;Sr&lt;/mtext&gt;&lt;/msub&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msup&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1.65&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;0.24&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;mtext&gt;An&lt;/mtext&gt;&lt;/msub&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;3.03&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;1.16&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;[&lt;/mo&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;368&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;142&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;27&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;141&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2.303&lt;/mn&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;mo&gt;]&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;log&lt;/mi&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mtext&gt;Ba&lt;/mtext&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msup&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1.43&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;0.20&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;msub&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;mtext&gt;An&lt;/mtext&gt;&lt;/msub&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;4.65&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;0.96&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;[&lt;/mo&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;337&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;037&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;22&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;969&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2.303&lt;/mn&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;mo&gt;]&lt;/mo&gt;&lt;/mrow&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;wh","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"651 ","pages":"Article 119141"},"PeriodicalIF":4.8,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746062","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":"Active, long-lived upper-plate splay faulting revealed by thermochronology in the Alaska subduction zone","authors":"Suoya Fan ,&nbsp;Kristin D. Morell ,&nbsp;Donald M. Fisher ,&nbsp;Hugues Raimbourg ,&nbsp;Vincent Famin ,&nbsp;Kristijan Rajič","doi":"10.1016/j.epsl.2024.119140","DOIUrl":"10.1016/j.epsl.2024.119140","url":null,"abstract":"<div><div>The lack of subaerial forearc geological records in active subduction zones has hindered our understanding of the roles of upper-plate structures and their interactions with plate interface processes in accommodating forearc deformation. Forearc splay faults, a type of upper-plate structure, are of particular interest due to their high efficiency in triggering tsunamis during great earthquakes. The coastal area of the Kodiak Islands, Alaska, USA exhibits stratigraphic and geomorphologic records of Miocene to Recent vertical tectonism and Quaternary thrust faults, suggesting potential splay-fault-involved deformation over geological timescales. To better understand the mechanisms of forearc long-term strain accumulation and the roles of splay faults, we investigate the spatial and temporal pattern of recent forearc exhumation in the Kodiak accretionary prism by conducting zircon and apatite (U-Th)/He (ZHe and AHe) thermochronologic analyses and thermal history modeling. These results are supplemented by field investigations, detrital zircon geochronology analyses and offshore active fault mapping. Most of the ZHe ages record cooling through the ZHe closure temperature in the late Eocene-early Oligocene, temporally and spatially consistent with the Eocene-early Oligocene broad antiformal exhumation previously documented by zircon and apatite fission track thermochronological ages. However, the AHe ages record cooling through the AHe closure temperature from early Miocene to Pliocene and exhibit an overall trenchward younging trend, with all the Pliocene ages (3–5 Ma) in the regions closest to the trench. Our thermal history modeling and field survey suggest that the trenchward coastal area of the Kodiak Islands experienced a change from early-middle Miocene basin subsidence to recent deformation and rapid uplift from 6–7 Ma to recent, while the rest of the island experienced an early-middle Miocene decrease in the prolonged exhumation from the Eocene-Oligocene. The newly revealed long-term exhumation pattern resembles the estimated uplift patterns based on elevated marine terraces and geodetic data. The early-middle Miocene change in exhumation pattern might be caused by a change in the dominant deformation mechanism affecting the Kodiak Islands, from broad underplating along the subduction interface mainly during the Eocene-Oligocene to hanging-wall uplift due to an active crustal splay thrust fault system since the late Miocene (the Kodiak Shelf Fault). We further discuss the dip-slip rate and geometry of the Kodiak Shelf Fault system and how inherited forearc upper-plate structures and lithology may affect forearc fluid distribution and facilitate the development and persistent deformation of the Kodiak Shelf Fault system.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"650 ","pages":"Article 119140"},"PeriodicalIF":4.8,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746558","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":"Numeric ring-reconstructions based on massifs favor a non-oblique south pole-Aitken-forming impact event","authors":"Hannes Bernhardt ,&nbsp;Jessica M. Walsh ,&nbsp;Leon M. Schröder ,&nbsp;Jaclyn D. Clark ,&nbsp;Megan R. Henriksen ,&nbsp;Christopher S. Edwards","doi":"10.1016/j.epsl.2024.119123","DOIUrl":"10.1016/j.epsl.2024.119123","url":null,"abstract":"<div><div>The size and shape of ring structures around the South Pole-Aitken basin (SPA) have been subject of several studies over the past decades. Most investigations considered long wavelength signatures such as the topographic outline of the extant basin floor or orbital observations of elemental abundances, all of which are oval or crescent-shaped and therefore implied an elliptic SPA formed by an oblique impact. Here we present a novel dataset of 286 circum-SPA massifs taller than 1000 m prominence, 201 of which we interpret as likely ring remnants based on morphology and location. Using a gradient-based optimization algorithm, we performed three numeric fits of these massifs, each consisting of an outer and an inner ellipse. While one fit included all 201 likely ring remnants, the two other fits included only massifs taller than 2160 m prominence or such that show a negative Bouguer anomaly (like the Outer Rook Ring around Orientale basin). A set of massifs that are part of non-ambiguous, relatively intact SPA-ring segments were given the same weight as all other massifs in every fit. The sizes of our three fits are relatively similar (variances ≤ 3.7%) with semimajor and semiminor axes of the outer ellipses ranging from 1099.4 km to 1126.9 km and 1060.0 km to 1099.4, respectively, and those for the inner ellipses from 946.2 km to 947.4 km and 910.2 to 941.3 km, respectively. As the two more exclusive fits discard massifs that are part of the relatively intact ring segments, we tentatively favor our more inclusive fit using all 201 likely ring remnants, which also has the lowest loss per datapoint value. All our fits have ellipticities ≤ 1.06 resulting in a near-circular SPA, which should have required an impact at a non-oblique angle of well over 44°. Compared to previously assumed lower impact angles around 30° to 45°, 2D and 3D models by previous studies suggest that such a non-oblique SPA-forming impact would increase the volume of generated impact melt, excavation depth, and diameter of the transient cavity, albeit only moderately by up to 20%. The energy injected by the SPA-forming event might be smaller in a non-oblique case because the size of the basin is determined only by the vertical component of the impactor trajectory, allowing for a lower impact energy to explain the diameter of SPA. Most decisively, though, a non-oblique scenario would imply a more symmetric distribution of ejecta, predicting an up to 10 km thick blanket at the South Pole, where oblique scenarios estimated only very small amounts of SPA ejecta. This is in agreement with increased olivine abundances in the regolith at the Chandrayaan 3 landing site and would imply SPA ejecta, including materials from the lower crust and upper mantle, to be relatively widespread in the Artemis Exploration Zone.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"650 ","pages":"Article 119123"},"PeriodicalIF":4.8,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746557","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":"Did the terrestrial planets of the solar system form by pebble accretion?","authors":"A. Morbidelli ,&nbsp;T. Kleine ,&nbsp;F. Nimmo","doi":"10.1016/j.epsl.2024.119120","DOIUrl":"10.1016/j.epsl.2024.119120","url":null,"abstract":"<div><div>The dominant accretion process leading to the formation of the terrestrial planets of the Solar System is a subject of intense scientific debate. Two radically different scenarios have been proposed. The classic scenario starts from a disk of planetesimals which, by mutual collisions, produce a set of Moon to Mars-mass planetary embryos. After the removal of gas from the disk, the embryos experience mutual giant impacts which, together with the accretion of additional planetesimals, lead to the formation of the terrestrial planets on a timescale of tens of millions of years. In the alternative, pebble accretion scenario, the terrestrial planets grow by accreting sunward-drifting mm-cm sized particles from the outer disk. The planets all form within the lifetime of the disk, with the sole exception of Earth, which undergoes a single post-disk giant impact with Theia (a fifth protoplanet formed by pebble accretion itself) to form the Moon. To distinguish between these two scenarios, we revisit all available constraints: compositional (in terms of nucleosynthetic isotope anomalies and chemical composition), dynamical and chronological. We find that the pebble accretion scenario is unable to match these constraints in a self-consistent manner, unlike the classic scenario.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"650 ","pages":"Article 119120"},"PeriodicalIF":4.8,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722696","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":"Soft barrier to megathrust rupture enabled by serpentinized mantle wedge: The Chile subduction zone","authors":"Kelin Wang ,&nbsp;Haipeng Luo ,&nbsp;Jiangheng He ,&nbsp;Matias Carvajal","doi":"10.1016/j.epsl.2024.119115","DOIUrl":"10.1016/j.epsl.2024.119115","url":null,"abstract":"<div><div>How temperature and petrology control the seismogenesis of the deeper megathrust and associated hazard is poorly understood. It was previously proposed that the serpentinized mantle wedge would limit seismic rupture, but modern observations show many recent earthquakes to have ruptured far deeper than the mantle wedge corner (MWC). However, the notion of mantle wedge serpentinite impeding seismic rupture is still of great scientific value. Here, by comparing model predictions of megathrust temperature and petrology with instrumentally constrained slip distributions of megathrust earthquakes along the Chile margin, we propose a new hypothesis based on the contrasting frictional behaviours of different serpentine polymorphs widely reported in the literature. At low slip rates, lizardite (and chrysotile) exhibits rate-strengthening and hence stable-sliding, but antigorite, given high enough temperatures, exhibits rate-weakening and hence stick-slip. However, they both undergo dynamic weakening at high slip rates and thus can facilitate rupture propagation. Along most of the Chile margin, as in most other global subduction zones, the megathrust at and immediately downdip of the MWC is rich in lizardite. The lizardite-serpentinite impedes but cannot always stop seismic rupture, forming a soft barrier. Farther downdip, the megathrust is rich in antigorite. Antigorite patches and their dense collections can facilitate rupture propagation and even initiation, and some of the stronger patches can radiate abundant short-period seismic energy. This MWC “soft-barrier” hypothesis explains the different modes of downdip slip distribution observed along Chile: bimodal slip straddling the MWC, slip confined downdip or updip of the MWC, and slip predominantly updip of the MWC with a deep extension crossing the MWC. The hypothesis is qualitatively compatible with global observations of megathrust seismicity and embraces the exception of very warm subduction zones.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"650 ","pages":"Article 119115"},"PeriodicalIF":4.8,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722697","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":"Multilevel Mechanisms Driving Intraplate Volcanism in Central Mongolia Revealed by Adjoint Waveform Tomography of Receiver Function and Ambient Noise Data","authors":"Mijian Xu ,&nbsp;Kai Wang ,&nbsp;Jing Chen ,&nbsp;Jing He ,&nbsp;Qinya Liu ,&nbsp;Yiduo Liu ,&nbsp;Zhouchuan Huang ,&nbsp;Ping Tong","doi":"10.1016/j.epsl.2024.119137","DOIUrl":"10.1016/j.epsl.2024.119137","url":null,"abstract":"<div><div>The genesis of the Cenozoic intraplate volcanism in Central Mongolia, characterized by sustained and low-volume eruptions remains debated due to the lack of a comprehensive model to interpret the Cenozoic volcanic activities. Here, we introduce a high-resolution 3D velocity model of the Hangay Dome, using a novel joint method which combines receiver function adjoint tomography and ambient noise adjoint tomography. The small-scale low-velocity zones in the crust and uppermost mantle reveal a crustal magma reservoir and partially molten subcontinental lithospheric mantle (SCLM). Melt fraction estimation indicates low-degree partially molten crust and SCLM. Combining previous geophysical and geochemical observations, we suggest that the volcanism in the Hangay Dome is driven by multilevel mechanisms. The remnant Mesozoic volatiles triggered upper mantle upwelling. This upwelling accumulated in the asthenosphere, heating the SCLM, and prompted its low-degree partial melting. The molten SCLM caused local lithospheric thinning and facilitated the magmatic underplating in the lower crust, eventually leading to the formation of the crustal magma reservoir.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"650 ","pages":"Article 119137"},"PeriodicalIF":4.8,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722698","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":"Melting the Marinoan Snowball Earth: The impact of deglaciation duration on the sea-level history of continental margins","authors":"Freya K. Morris ,&nbsp;Tamara Pico ,&nbsp;Jessica R. Creveling ,&nbsp;John Grotzinger","doi":"10.1016/j.epsl.2024.119132","DOIUrl":"10.1016/j.epsl.2024.119132","url":null,"abstract":"<div><div>The termination of the Marinoan Snowball Earth (∼635 Ma) represents a significant transition in Earth's climate. Cap carbonate strata, and underlying glaciogenic deposits, record global deglaciation and preserve diverse relative sea-level histories, representing the intersection of global mean sea-level rise with regional forcings such as glacial isostatic adjustment and sedimentation. For example, at cap carbonate outcrops in the Naukluft Mountains of central Namibia, facies transitions reveal two intervals of water-depth deepening and shallowing. While many factors may have contributed to this deglacial pattern of relative sea-level change, here we consider the possibility that this, and other, non-monotonic sea-level histories, were driven by glacial isostatic adjustment. We modeled relative sea-level change due to glacial isostatic adjustment for a globally synchronous and continuous Marinoan deglaciation, and explored how the duration of deglaciation impacts the range of resulting relative sea-level patterns across continental margins. Short Snowball deglaciation durations, on the order of ∼2 kyr, result in exclusive relative sea-level rise, or relative sea-level rise followed by relative sea-level fall but cannot drive two distinct phases of relative sea-level fall. However, longer duration Snowball deglaciations, of ∼10–30 kyr, can drive two distinct intervals of relative sea-level rise and fall across much of the width of a continental margin, which may have contributed to the stratal patterns observed in Naukluft Mountains cap carbonate, though we cannot exclude that the pattern arises from changes in sediment supply or other factors. This work underlines the need for better constraints on the areal distribution and volume of Marinoan ice sheets from field observations, as well as plausible deglacial durations from global climate models.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"650 ","pages":"Article 119132"},"PeriodicalIF":4.8,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705426","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}