Earth and Planetary Science Letters最新文献

{"title":"Subduction of an oceanic triple junction: Geodynamic implications of successive mid-ocean ridge subduction","authors":"Jorge Sanhueza ,&nbsp;Gonzalo Yáñez ,&nbsp;Sofía Lagarrigue","doi":"10.1016/j.epsl.2025.119444","DOIUrl":"10.1016/j.epsl.2025.119444","url":null,"abstract":"<div><div>Mid-ocean ridge subduction and subsequent opening of slab windows have profound implications in the spatio-temporal evolution of convergent margins. The geological record, geophysical observations and numerical studies have accounted for the geodynamic implications in the overriding plate and the upper mantle in modern and ancient settings. Geological consequences are the disruption of the arc magmatism and the emplacement of extensive backarc plateau lavas. While geophysical imaging has documented low seismic anomalies associated with mantle upwelling. However, the subduction of an oceanic triple junction is a complex process that has been identified through tectonic reconstructions but has not been tested yet. In this contribution, we provide a simplified numerical model to understand the geodynamic and thermal consequences due to a subducted oceanic triple junction. We conducted 2D thermomechanical simulations with appropriate initial conditions to reproduce the long-term effects (up to 14 Ma) of successive mid-ocean ridge subduction. Model results show migration of partial melts in the upper mantle that lead to the generation of ridge jumps, slab remnants and a new subduction zone, having an impact in tectonic reorganizations and terrane accretion. In addition, long-term thermal anomalies (60-90 °C/km) in the overriding plate can only be developed with a proper combination of geodynamics settings and erosional conditions (1 mm/yr). Finally, we used our modeling results to provide an integrated geodynamic evolution at Tierra del Fuego in southernmost South America, in which the two episodes of mid-ocean ridge subduction and climate-driven erosional processes during the Miocene are the key controlling factors.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"664 ","pages":"Article 119444"},"PeriodicalIF":4.8,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072245","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":"Quantifying salt extrusion versus surface salt flow rates at Mt. Sedom to gain insights on its mechanics and potential external atmospheric forcing","authors":"Man Wai Yip ,&nbsp;A.Alexander G. Webb ,&nbsp;Pablo J. González","doi":"10.1016/j.epsl.2025.119446","DOIUrl":"10.1016/j.epsl.2025.119446","url":null,"abstract":"<div><div>The study of salt tectonics is essential due to its relevance in locating hydrocarbon reserves, providing storage for fuels and waste, and offering insights into extraterrestrial geology. Despite decades of research, salt extrusion and flow rates at the surface remain poorly characterized, even with frequent confusing terminology. In our study, we aim to separate both phenomena at one of the best test sites on Earth, Mt. Sedom, a prominent salt extrusion site in a tectonically active basin. We utilized InSAR (Interferometric Synthetic Aperture Radar) techniques to measure surface salt motion with high temporal resolution, analyzing 9.5 years of Sentinel-1 data to derive both vertical and horizontal displacement components. Our approach improves previous estimates that used only line-of-sight (LOS) measurements. We are able to estimate vertical uplift rates directly above the salt extrusion channel location inferred using mechanical modeling. We propose that these estimates are a much closer representation of the actual salt extrusion rates, and largely independent of the typically overlapping surface gravity-driven flow dynamics. The InSAR time-series suggests that thermal expansion is a first-order driver of the observed seasonal uplift and subsidence patterns. Moreover, for the first time in Mt. Sedom, displacement changes in response to weather (rainfall) were inferred to be statistically significant. We conclude that any rainfall event, regardless of its magnitude, might be sufficient to enhance salt flow rate. This can be explained as a result of salt dissolution and increased gravity-driven downslope movement in the salt glacier as the salt becomes wet, due to increased surface load or reduced viscous/frictional forces. By integrating InSAR measurements, mechanical modeling, and meteorological data, this study provides new constraints on surface salt motion at Mt. Sedom, improving our understanding of its driving mechanisms. Most importantly, our results reveal an immediate response of salt motion to rainfall, providing new insights into interactions between atmospheric and crustal processes.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"664 ","pages":"Article 119446"},"PeriodicalIF":4.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072244","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":"Sound velocity measurements of γ-(Mg0.91Fe0.09)2SiO4 show that the ringwoodite to bridgmanite and ferropericlase phase transformation does not produce the seismically observed 660 km discontinuity","authors":"Rong Huang ,&nbsp;Andrew R. Thomson ,&nbsp;John P. Brodholt ,&nbsp;Wilson A. Crichton ,&nbsp;Anja Rosenthal ,&nbsp;Dmitrii Druzhbin ,&nbsp;Nicholas Backhouse ,&nbsp;Isaac Taschimowitz ,&nbsp;Dimitrios Bessas ,&nbsp;Sergey Yaroslavtsev ,&nbsp;Biao Wang","doi":"10.1016/j.epsl.2025.119416","DOIUrl":"10.1016/j.epsl.2025.119416","url":null,"abstract":"<div><div>The canonical model of Earth’s interior directly links the global 410 and 660 km seismic discontinuities to olivine’s high pressure phase transitions in a pyrolite mineral assemblage. However, previous studies observe that the expected sound velocities of pyrolite are too low to match 1-dimensional seismic models in the lower mantle transition zone (MTZ). In this study, we report measurements of the elastic properties of (Mg_0.9Fe_0.1)₂SiO₄ ringwoodite (Rw90), the dominant component of pyrolite between 520 km and 660 km depths, using pulse-echo ultrasonic interferometry combined with synchrotron X-radiation in the multi-anvil press up to 21 GPa and 1650 K. Our results show that <em>V</em>_P and <em>V</em>_S of anhydrous Rw90 (0.003–0.035 wt.% H₂O, 5.6 ± 1.2% Fe³⁺/Fe^tot) are both higher than predictions at MTZ conditions from previous studies, with a smaller increase for <em>V</em>_S. Simultaneous fitting of <em>PVT-V</em>_P<em>-V</em>_S data yields global fit equation of state (EoS) parameters of <em>V</em>₀= 39.69(2) cm³/mol, <em>K</em>₀ = 183(4) GPa, <em>K</em>₀′ = 5.5(3), <em>G</em>₀ = 125(2) GPa, <em>G</em>₀′ = 1.3(1), <em>q</em>₀ = 0.3(3), <em>γ</em>₀ = 1.27(4), <em>θ</em>₀ = 1100(100) K and <em>η</em>_S0 = 3.5(2). Combining results with literature data, our predicted <em>V</em>_S for pyrolite produces a sharp discontinuity consistent with seismic models, although <em>V</em>_S is slightly lower than observed in the lower MTZ. In contrast, we find that pyrolite would not produce a large and sharp <em>V</em>_P discontinuity at 660 km as the jump in <em>V</em>_P caused by the decomposition of Rw90 is too small. A homogenous assemblage of pyrolite cannot, therefore, currently explain the seismic features in the lower MTZ. We also find that neither an accumulation of harzburgite nor basaltic crust immediately above or below the 660 km discontinuity explains the observations. Instead, either a heterogeneous mixture of some other chemically distinctive components is required or more prosaically, the elastic properties of all the other mantle phases need reevaluation.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119416"},"PeriodicalIF":4.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068942","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":"Duration of isobaric heating and slab rollback in the Aegean extensional province, Eastern Mediterranean: Evidence from garnet diffusion modelling","authors":"Alexandre Peillod ,&nbsp;Benjamin Hess ,&nbsp;Evangelos Moulas ,&nbsp;Simon Hector ,&nbsp;Clifford G.C. Patten ,&nbsp;Aratz Beranoaguirre ,&nbsp;Uwe Ring","doi":"10.1016/j.epsl.2025.119409","DOIUrl":"10.1016/j.epsl.2025.119409","url":null,"abstract":"<div><div>A phase of isobaric heating during exhumation of high-pressure rocks is often reported, but the tectonic significance of isobaric heating remains uncertain. Constraining the timescales of isobaric heating is essential for connecting the heating to tectonic processes of lithospheric thickening and extension. An isobaric heating phase has been reported for the Cycladic Blueschist Unit in the Hellenide orogen of Greece. We present diffusion modeling of major elements in garnet using data from Naxos Island to provide new independent estimates of the duration of isobaric heating. We also present radioactive trace element analyses of the Cycladic basement and a heat conduction model to explore the heat production generated in the basement and its influence on isobaric heating. Our model indicates that isobaric heating occurred over <em>∼</em>9.7 Myr, during which the Cycladic basement generated enough heat to explain the observed temperature increase. At the end of this heating phase, the temperature increase caused a significant drop in crustal strength, which controlled the style of crustal extensional deformation during subsequent rollback of the subducting slab. Our work implies that the underthrusting of radiogenic material in convergent settings produces sufficient heat to significantly increase temperature which weakens the crust and enables pervasive deformation.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119409"},"PeriodicalIF":4.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068940","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":"Rock fabric and hydromechanical evolution from Quartz to clay rich faults and implications for slip stability","authors":"M.M. Scuderi ,&nbsp;C. Giorgetti ,&nbsp;C. Wibberley ,&nbsp;C. Collettini","doi":"10.1016/j.epsl.2025.119422","DOIUrl":"10.1016/j.epsl.2025.119422","url":null,"abstract":"<div><div>Fault rock heterogeneity has a dominant effect on frictional and fluid flow properties of faults, yet the study of how fault hydromechanical properties are coupled, evolve with fabric and influence slip behaviour is still in its infancy. Here, we show that the increase in clay content within a quartz-bearing experimental fault promotes a fabric evolution from a load-bearing granular framework to an interconnected foliated and clay-rich network. This fabric evolution causes a significant reduction in frictional strength, a marked decrease in permeability, and enhanced frictional stability. Fault stability is favoured by contact area saturation (mechanical effect) acting in concert with fault dilation associated to a reduction in pore fluid pressure promoted by transient undrained conditions within the low permeability, clay-rich faults (hydromechanical effect). Our results indicate that fault rock fabric and associated hydromechanical properties exert a primary control on fault slip behaviour. The enhanced stability within pressurized clay-rich faults matches well with observations of aseismic slip during hydraulic stimulations of shales and models proposing dilation strengthening as a mechanism for the occurrence of slow slip events in clay-rich sediments at shallow crustal levels.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119422"},"PeriodicalIF":4.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068937","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":"Retroarc foreland basins document past oceanic subduction history","authors":"Xuesong Ding ,&nbsp;Carolina Lithgow-Bertelloni","doi":"10.1016/j.epsl.2025.119412","DOIUrl":"10.1016/j.epsl.2025.119412","url":null,"abstract":"<div><div>Retroarc foreland basins are natural laboratories for reconstructing the history of oceanic plate subduction. However, disentangling that history from the basin stratigraphic record remains challenging due to lack of quantification of how oceanic subduction and other geological processes separately or collectively affect the basin sedimentation. We aim to partially fill that gap by modeling the stratigraphic record of retroarc foreland basins under various subduction and mountain building events. We systematically evaluate the impacts of four parameters - slab geometry (or slab dip <em>θ</em>), surface uplift rate (<em>U</em>), elastic thickness of overriding plate (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>e</mi></mrow></msub></math></span>), and surface erosion efficiencies (<span><math><msub><mrow><mi>κ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>) - on basin geometry and stratigraphic patterns. Our results reveal that shallow basin geometries are promoted by high <em>θ</em> and <em>U</em>, and low <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>e</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>κ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>. Basin width increases as <em>U</em> and <span><math><msub><mrow><mi>κ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> increase, but exhibits no universal scaling with <em>θ</em> and <span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>e</mi></mrow></msub></math></span>, due to its dependence on sediment supply to the basin. Progradation of fluvial deposits positively correlates to the magnitude of flexural rebound (uplift), suggesting a novel proxy for estimating lithospheric elastic thickness. Furthermore, our model demonstrates that slab flattening can drive large-scale depocenter migration, mirroring the patterns observed in the Cordilleran retroarc basins in North America. Lastly, by normalizing basin geometry, we categorize accommodation-dominant or supply-dominant basins, which helps to evaluate the relative contribution of operated processes on basin formation. This work advances quantitative linkages between stratigraphic architecture and the interplay of subduction dynamics, mountain building, and surface processes, offering predictive tools to extract past geodynamic and tectonic signals from stratigraphic records.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119412"},"PeriodicalIF":4.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068938","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":"Tectonic evolution and thermal structure of the Gold Butte normal fault block, Nevada: New insights from multiple diffusion domain (MDD) 40Ar/39Ar K–feldspar analyses","authors":"Martin S. Wong ,&nbsp;Phillip B. Gans","doi":"10.1016/j.epsl.2025.119441","DOIUrl":"10.1016/j.epsl.2025.119441","url":null,"abstract":"<div><div>The Gold Butte normal fault block in Nevada has been interpreted as one of the structurally thickest intact upper crustal sections exposed in the western United States. As such, this fault block has been extensively used as a natural laboratory both to investigate the tectonics of large magnitude extension, as well as to evaluate new and existing thermochronometers. However, recent work has led to debate about the tectonic history of the region and the degree to which the fault block is intact. We report new thermochronologic results derived from multiple diffusion domain (MDD) modeling of ⁴⁰Ar/³⁹Ar K-feldspar analyses that shed new light on the accuracy of this method as well as the tectonic evolution of the fault block. ⁴⁰Ar/³⁹Ar K-feldspar ages decrease systematically towards the west to a paleodepth of ∼14 km and MDD models accurately reproduce many key features of the known tectonothermal history of the fault block, including the inception, rate, and magnitude of rapid cooling produced by tectonic exhumation. These MDD models also yield Miocene temperatures that match the known pre-extensional thermal structure of the block from other thermochronologic studies. These results provide strong evidence that MDD modeling of K-feldspar analyses can provide geologically meaningful and accurate continuous thermal histories. At the deepest inferred paleodepths however, the ⁴⁰Ar/³⁹Ar K-feldspar data show a clear repetition of the age gradients and MDD models yield Miocene temperatures that are 80–100 °C cooler than models assuming an intact fault block predict. We propose that the deepest parts of the block lie in the hanging wall of a previously unrecognized normal fault that repeats the westernmost part of the block. An analysis of prior thermochronology strongly supports this hypothesis. These results demonstrate the utility of high precision ⁴⁰Ar/³⁹Ar K-feldspar analyses and MDD models for resolving structural and tectonic problems.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119441"},"PeriodicalIF":4.8,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068939","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":"Origin of moderately volatile elements in Earth inferred from mass-dependent Ge isotope variations among chondrites","authors":"Elias Wölfer ,&nbsp;Christoph Burkhardt ,&nbsp;Francis Nimmo ,&nbsp;Thorsten Kleine","doi":"10.1016/j.epsl.2025.119435","DOIUrl":"10.1016/j.epsl.2025.119435","url":null,"abstract":"<div><div>The bulk silicate Earth (BSE) is depleted in moderately volatile elements, indicating Earth formed from a mixture of volatile-rich and -poor materials. To better constrain the origin and nature of Earth's volatile-rich building blocks, we determined the mass-dependent isotope compositions of Ge in carbonaceous (CC) and enstatite chondrites. We find that, similar to other moderately volatile elements, the Ge isotope variations among the chondrites reflect mixing between volatile-rich, isotopically heavy matrix and volatile-poor, isotopically light chondrules. The Ge isotope composition of the BSE is within the chondritic range and can be accounted for as a ∼2:1 mixture of CI and enstatite chondrite-derived Ge. This mixing ratio appears to be distinct from the ∼1:2 ratio inferred for Zn, reflecting the different geochemical behavior of Ge (siderophile) and Zn (lithophile), and suggesting the late-stage addition of volatile-rich CC materials to Earth. On dynamical grounds it has been argued that Earth accreted CC material through a few Moon-sized embryos, in which case the Ge isotope results imply that these objects were volatile-rich, presumably because they were either undifferentiated or accreted volatile-rich objects themselves before being accreted by Earth.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119435"},"PeriodicalIF":4.8,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942681","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":"Early pyroxene crystallisation deep below mid-ocean ridges","authors":"Teresa Ubide ,&nbsp;David T. Murphy ,&nbsp;Robert B. Emo ,&nbsp;Michael W.M. Jones ,&nbsp;Marco A. Acevedo Zamora ,&nbsp;Balz S. Kamber","doi":"10.1016/j.epsl.2025.119423","DOIUrl":"10.1016/j.epsl.2025.119423","url":null,"abstract":"<div><div>The oceanic crust grows in mid-ocean ridges where melt generation is followed by magmatic processing through vertically extended mush systems. The composition of global mid-ocean ridge basalts (MORBs) requires early crystallisation of clinopyroxene at depth, however, petrological observations in MORBs (scarce clinopyroxene phenocrysts) and gabbros (clinopyroxene occupying intercumulus space) suggest clinopyroxene crystallisation is late and restricted to relatively low pressure. These competing inferences constitute the long-standing ‘pyroxene paradox’. Here, we report the discovery of rare (up to 4 vol.%) relict clinopyroxene ‘cores’ in intercumulus clinopyroxene from the Atlantis Bank slow spreading centre (southwest Indian Ridge ODP Hole 735B). We exploit slowly diffusing trace elements Cr, Zr and Ti to uncover relics that preserve evidence of an early, transported and largely resorbed, mafic pyroxene mush. Using dimensionality reduced semantic segmentation of elemental maps, we define the mode and outline of antecryst cores. The cores have rare earth element systematics that agree with crystallisation from MORB liquids, providing an empirical connection between deep melt crystallisation and erupted basalts. In contrast, clinopyroxene rims are notably enriched in incompatible elements because of late melt-rock reaction in the gabbroic mush. The rims have strong negative Eu anomalies, indicating crystallisation after development of plagioclase-dominated mush at low pressure. Thermodynamic modelling of clinopyroxene crystallisation from MORB parental melts at high pressure (8–10 kbar) reproduces the large spread in MORB Ca-Al-Mg systematics and generates a strong density contrast between the evolving liquid and cumulate pyroxenites. At the buoyancy peak, crystallinity remains low, liquid compositions approach observed MORB chemistries, and clinopyroxene compositions match antecryst cores. Our work supports the idea that polybaric mid-ocean ridge crystal mushes act as multi-stage magma filters, with cryptic clinopyroxene crystallisation as a driver of the early evolution of the oceanic crust.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119423"},"PeriodicalIF":4.8,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935121","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":"The extraterrestrial dust accretion rate on Earth at Dome C, Antarctica: a fresh look with 3He","authors":"G. Fénisse ,&nbsp;D.V. Bekaert ,&nbsp;P.-H. Blard ,&nbsp;J. Duprat ,&nbsp;I. Mattia ,&nbsp;M. Genge ,&nbsp;M.D. Suttle ,&nbsp;O. Barres ,&nbsp;C. Engrand ,&nbsp;Y. Marrocchi","doi":"10.1016/j.epsl.2025.119396","DOIUrl":"10.1016/j.epsl.2025.119396","url":null,"abstract":"<div><div>Interplanetary dust particles (IDPs) and micrometeorites (MMs), from 1 µm to 5 mm, are the primary source of extraterrestrial (ET) material currently accreted on Earth. The flux of ET particles smaller than ∼50 µm is typically determined through optical counting, but it remains uncertain and may deviate from predictions made by numerical simulations. The volatile element content carried by this flux is still not well-constrained and is influenced by the potential effects of atmospheric heating.</div><div>We developed a clean, pressurized system to extract cosmic dust from ∼38 kg of clean snow collected near the Concordia station (Dome C, Antarctica). We measured helium isotope concentrations in various granulometric fractions (&gt; 62 µm, 25–62 µm, 5–25 µm and &lt; 5 µm). The inferred global ³He_ET annual flux is (1.25±0.03) × 10⁻¹² ccSTP·cm⁻²·ka⁻¹ (weighted mean±1SD), consistent with previous ³He_ET flux estimates from marine sediments and polar samples. Our data shows that the majority of the ³He_ET flux (70 %) is carried by particles in the 5–25 µm size range, with 20 % attributed to the 25–62 µm fraction. Using an empirical relationship between ³He_ET concentrations and cosmic particle mass, we convert these fluxes into a global ET mass flux for particle diameters &lt; 100 µm of (3.5±0.5) kilotons·a⁻¹ (weighted mean±1SD). This result is about 3 times higher than collection estimates from (Rojas et al., 2021) and aligns with CABMOD-ZoDy modeling, after atmospheric entry (Carrillo-Sánchez et al., 2020). This ³He_ET method is suited for detecting particles smaller than 100 µm, while collection results are more relevant for larger fractions.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"663 ","pages":"Article 119396"},"PeriodicalIF":4.8,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935248","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}