Earth and Planetary Science Letters最新文献

{"title":"Garnet as a reliable timekeeper in Archean polymetamorphic terranes","authors":"Jonas Kaempf ,&nbsp;Chris Clark ,&nbsp;Tim E. Johnson ,&nbsp;Mudlappa Jayananda ,&nbsp;Martin Hand ,&nbsp;Krishnan Sajeev","doi":"10.1016/j.epsl.2025.119545","DOIUrl":"10.1016/j.epsl.2025.119545","url":null,"abstract":"<div><div>Reliably reconstructing the pressure–temperature–time (<em>P–T–t</em>) history of Archean polymetamorphic terranes is key to gaining insight into the tectonic processes operating on the early Earth. In this regard, garnet is arguably the most important mineral. Not only does it capture information about both the timing and the conditions of metamorphism, but can also preserve this record through multiple tectonic cycles. Here, we used in situ Lu–Hf dating of garnet from two greenstone belts in the Western Dharwar Craton (WDC) in southern India to investigate their tectono-metamorphic evolution. Garnet ages reveal a record of two distinct medium- to high-pressure tectono-metamorphic events during the Archean eon. Whereas garnet from the Holenarsipur Greenstone Belt grew during late Neoarchean metamorphism at 2.53 Ga, garnet from the Kalyadi Greenstone Belt records a 2.96 Ga regional metamorphic episode that has not previously been recognized. Coupled with results from in situ monazite U–Pb dating and thermodynamic modelling, our data suggest that the two neighboring greenstone belts, which were previously thought to share a common tectonothermal history, underwent contrasting <em>P–T–t</em> evolutions throughout the Mesoarchean and Neoarchean, challenging existing models for the tectonic evolution of the WDC. Obtaining reliable age constraints in polymetamorphic terranes via in situ Lu–Hf dating of garnet that can be directly linked to <em>P–T</em> information represents a key advance in deciphering the cryptic record of crustal metamorphism throughout Earth history.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"668 ","pages":"Article 119545"},"PeriodicalIF":4.8,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680585","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":"Thermodynamics of Fe-S-O-C-H liquids: Implications for the Martian core","authors":"Jac van Driel ,&nbsp;Lidunka Vočadlo ,&nbsp;John Brodholt","doi":"10.1016/j.epsl.2025.119540","DOIUrl":"10.1016/j.epsl.2025.119540","url":null,"abstract":"<div><div>We present a comprehensive investigation into the composition of the Martian core. We use new density functional theory (DFT) calculations, which consider in detail the magnetic properties of the Fe alloys, essential for obtaining the correct density and velocities. We then fit our results to a new Gaussian Process Regression (GPR) equation of state (EOS). Using this GPR-EOS we search for all compositions of the Martian core in the system Fe-S-O-C-H that match both the density and compressional wave speeds of a liquid Martian core throughout its entire depth range. We consider different models for the interior of Mars – in particular, those with and without a deep melt layer at the base of the Martian mantle (<span><span>Irving et al., 2023</span></span>; <span><span>Samuel et al., 2023</span></span>; <span><span>Khan et al., 2023</span></span>). The existence of a deep melt layer is important as it revises previous estimates for the core's size and density. We consider a range of core-mantle boundary temperatures from 1900 K to 2850 K, although we find that temperature has a relatively small effect on the possible compositions. As with previous studies, and also for the Earth, we find many different compositions that are able to match the geophysical observations of Mars' core density (<em>ρ</em>) and velocity (<span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>ϕ</mi></mrow></msub></math></span>), regardless of which set of geophysical observations are used. All models require very high concentrations of light-elements of ≈ 50 mol% in line with previous work. The compositional variation can be reduced considerably by considering cosmochemical constraints on the maximum amount of sulphur, together with geochemical constraints on the partitioning. In this case, all solutions require very high hydrogen content of at least 0.5 wt% (27 mol%) and practically no oxygen.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"668 ","pages":"Article 119540"},"PeriodicalIF":4.8,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680587","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":"Electrostatic detachment of dust from the lunar surface: Microscopic fluctuations could be the key","authors":"Trinesh Sana ,&nbsp;S.K. Mishra","doi":"10.1016/j.epsl.2025.119544","DOIUrl":"10.1016/j.epsl.2025.119544","url":null,"abstract":"<div><div>We propose a solution to the fundamental problem and physical mechanism of dust detachment from the lunar surface. We conceptualize that the electrostatic charge fluctuation at microscopic scale could create a sufficient electric field and coulomb force to overcome the dust-surface adhesive force and detach the dust particles. Markovian process is manifested with Monte Carlo scheme to simulate the concept. The simulation establishes the random generation and annihilation of fluctuating charged microscopic spots. The results demonstrate the existence of microscopic charged spots, capable of inducing sufficient electric field and Coulomb force of the order of a few MV/m and 10s of pN, respectively, which creates favorable conditions for lunar dust detachment. This concept fits the gap and put forward a consistent mechanism describing dust dynamics and generation of dusty plasma scenario over Moon.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"668 ","pages":"Article 119544"},"PeriodicalIF":4.8,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680586","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":"An abrupt change in source materials for Chinese loess deposits at the Pliocene-Pleistocene boundary: Insights from K isotopes and modeling","authors":"Jun Mu ,&nbsp;Jiawei Da ,&nbsp;Hu Yang ,&nbsp;Junfeng Ji ,&nbsp;Lianwen Liu ,&nbsp;Weiqiang Li","doi":"10.1016/j.epsl.2025.119543","DOIUrl":"10.1016/j.epsl.2025.119543","url":null,"abstract":"<div><div>The eolian deposits on the Chinese Loess Plateau (CLP) are key archives of late Cenozoic climate changes and atmospheric circulation, However, the long-standing controversy about the stability of dust sources over the last ∼ 6 Myr limits our understanding of the genesis of the CLP and its paleoenvironment implications. Here we report that an abrupt decrease in K isotope compositions (δ⁴¹K) of the CLP eolian deposits occurred at ∼2.58 Ma, with loess/paleosol displaying δ⁴¹K values (-0.41 ‰ to -0.63 ‰) lower than the bulk-silicate-earth-like Red Clay values (-0.35 ‰ to -0.45 ‰). Furthermore, The δ⁴¹K values of eolian deposits are negatively correlated with the Na₂O/K₂O and Na₂O/Al₂O₃ ratios, with negligible influence from different grain size fraction. These observations indicate that the δ⁴¹K values are not controlled by post-depositional weathering at the CLP, but rather by an increased export of weathered detritus or recycled sediments from the Northeastern Tibetan Plateau, as revealed by K isotope surveys of potential source materials and Earth system model simulations. Our results further suggest that the intensified global cooling during the Quaternary promoted greater sediments erosion and altered the dynamics of the westerlies and the Siberian High, with important implications for understanding the paleoenvironment changes and reconstruction of the East Asian atmospheric circulation across the Pliocene-Pleistocene boundary.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"668 ","pages":"Article 119543"},"PeriodicalIF":4.8,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665890","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":"Organic carbon, sea level and carbonate weathering controls on marine carbon isotope perturbations across the Hirnantian glaciation","authors":"Jiaqiang Zhang ,&nbsp;Zhen Qiu ,&nbsp;Wenjiao Xiao ,&nbsp;Paul B. Wignall ,&nbsp;Weiliang Kong ,&nbsp;Benjamin J.W. Mills ,&nbsp;Yijun Xiong ,&nbsp;Simon W. Poulton","doi":"10.1016/j.epsl.2025.119539","DOIUrl":"10.1016/j.epsl.2025.119539","url":null,"abstract":"<div><div>The Hirnantian isotopic carbon excursion (HICE) records a dramatic perturbation to the global carbon cycle across the Late Ordovician Hirnantian glaciation. The HICE is characterized by variable duration and amplitude in global records, but its ultimate driver, and controls on the observed variability, are poorly understood. Here, we present a comprehensive compilation of geochemical data and paired carbon and calcium isotope records for two continuous Hirnantian sections at Wanhe and Shuanghe on the Yangtze Shelf (South China). Our results reveal a lateral gradient of up to 4 ‰ in organic carbon isotope (δ¹³C_org) values across the shelf, decreasing from nearshore to offshore. Carbonate carbon isotope (δ¹³C_carb) data from the Wanhe and Shuanghe sections also show pronounced variability, which cannot be fully explained by primary mineralogical changes or early marine diagenesis. We therefore interpret the spatial δ¹³C_org patterns as reflecting, at least in part, shelf-scale heterogeneity in seawater dissolved inorganic carbon isotope (δ¹³C_DIC) values. Our compilation further suggests that substantial organic carbon burial likely triggered the HICE, while sea-level change subsequently drove the asynchronous, spatially heterogeneous changes in seawater δ¹³C_DIC values. Additionally, enhanced carbonate weathering, linked to falling syn-glacial sea-level, amplified the spatial heterogeneity in regional marine δ¹³C_DIC values. Moderate δ¹³C_org changes (&lt;+2 ‰) are observed in central shelf areas across the Hirnantian glaciation, suggesting that the global carbon cycle perturbations during this ice age were of more modest amplitude than often suggested.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"667 ","pages":"Article 119539"},"PeriodicalIF":4.8,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633752","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":"Deep carbon sink in the East Asian mantle and its impact on atmospheric CO2 drawdown since the Cretaceous","authors":"Chun Yang ,&nbsp;Sheng-Ao Liu ,&nbsp;Hong-Yan Li ,&nbsp;Yi-Gang Xu","doi":"10.1016/j.epsl.2025.119541","DOIUrl":"10.1016/j.epsl.2025.119541","url":null,"abstract":"<div><div>The western Pacific oceanic slab has been deeply subducted into the mantle beneath East Asia since the early Cretaceous, eventually stagnating within the mantle transition zone (410–660 km). Here we present the first quantitative estimate of the flux of deeply subducted carbon beneath East Asia related to the Pacific slab and evaluate its impact on atmospheric CO₂ levels (<em>p</em>CO₂) since the Cretaceous. We compiled chemical and zinc isotopic data for the widely distributed East Asian intercontinental basalts (EAIBs; <em>N</em> = 399), which originated from partial melting of the upper mantle above the stagnated western Pacific slab. By using a melt CO₂ degassing correction and a \"melting-mixing\" model, we show that the formation of EAIBs involved ubiquitous magma mixing between silicate melts and carbon-rich melts. Consequently, the mantle source of EAIBs is estimated to have an unexpectedly high carbon content (297 ± 118 μg/g; 1σ), about three times the average carbon in the convecting mantle (110 ± 40 μg/g), primarily due to subducting carbon input from the western Pacific slab. Based on paleogeographic reconstruction models, we show that two peak periods of subducting carbon influx into the mantle transition zone sparked the deep carbon sink beneath East Asia. There is a gap of approximately 26 Ma between peak carbon subduction and widespread EAIB eruptions. This gap suggests that deep carbon sink beneath East Asia, due to inefficient mantle carbon outgassing, may have significantly contributed to the drawdown of atmospheric <em>p</em>CO₂ since the Cretaceous.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"667 ","pages":"Article 119541"},"PeriodicalIF":4.8,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655713","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 evolution of planetesimal reservoirs revealed by Fe-Ni isotope anomalies in differentiated meteorites","authors":"Fridolin Spitzer ,&nbsp;Timo Hopp ,&nbsp;Christoph Burkhardt ,&nbsp;Nicolas Dauphas ,&nbsp;Thorsten Kleine","doi":"10.1016/j.epsl.2025.119530","DOIUrl":"10.1016/j.epsl.2025.119530","url":null,"abstract":"<div><div>Differentiated meteorites sample planetesimals formed earlier than the parent bodies of chondritic meteorites. To evaluate whether these two generations of planetesimals formed from the same or distinct materials, we have analyzed the Fe and Ni isotopic compositions for a large set of differentiated meteorites, representing approximately 26 distinct parent bodies. Most of these samples are genetically related to the carbonaceous chondrite (CC)-type reservoir, which is thought to represent some portion of the outer disk. The new data reveal that early and late CC planetesimals cover a similar range of Fe and Ni isotopic compositions, indicating that all these bodies accreted from the same mixture of dust components, either in a long-lived pressure structure of the disk or in different substructures containing the same materials. Many differentiated meteorites have an isotopic composition similar to the late-formed CR chondrites, indicating that the CR chondrite reservoir was established early and remained isolated for essentially the entire disk lifetime. Finally, CI chondrites are the only CC chondrites whose isotopic composition is not represented among differentiated meteorites. Thus, planetesimals with CI chondrite-like isotopic compositions represent a late burst of planetesimal formation and possibly formed by a distinct mechanism and/ or in a different location from the other CC planetesimals.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"667 ","pages":"Article 119530"},"PeriodicalIF":4.8,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623660","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":"Hybrid mantle plumes with recycled and primordial nitrogen: Insights from plume-influenced basaltic glasses from Reykjanes Ridge and Rochambeau Bank","authors":"Kan Li ,&nbsp;Michael R. Hudak ,&nbsp;Michael W. Broadley ,&nbsp;Molly K. Anderson ,&nbsp;David V. Bekaert ,&nbsp;John A. Krantz ,&nbsp;Namitha Kumar ,&nbsp;Manuel Pimenta Silva ,&nbsp;Doshik Hahm ,&nbsp;Joshua M. Curtice ,&nbsp;Mark D. Kurz ,&nbsp;Peter H. Barry","doi":"10.1016/j.epsl.2025.119538","DOIUrl":"10.1016/j.epsl.2025.119538","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Sources of nitrogen (N) in the plume mantle source remains hotly debated between a primordial origin (i.e., acquired during Earth’s formation) and a recycled origin associated with subduction of surficial material. Although N isotope data for plume-derived magmas are limited, the available data show clear differences in N isotope compositions between plume (δ&lt;sup&gt;15&lt;/sup&gt;N &gt;-2 ‰) and the depleted mid-ocean-ridge basalt mantle sources (i.e., DMM; δ&lt;sup&gt;15&lt;/sup&gt;N = -5 ± 2 ‰). Here we present N-isotope and noble gas isotope data from two suites of well-characterized plume-influenced submarine basaltic glasses with high &lt;sup&gt;3&lt;/sup&gt;He/&lt;sup&gt;4&lt;/sup&gt;He: 1) the Rochambeau Bank in the northeastern Lau backarc basin (up to ∼23 R&lt;sub&gt;A&lt;/sub&gt;, where R&lt;sub&gt;A&lt;/sub&gt; refers to the atmospheric &lt;sup&gt;3&lt;/sup&gt;He/&lt;sup&gt;4&lt;/sup&gt;He ratio), and 2) the Reykjanes Ridge (up to ∼18 R&lt;sub&gt;A&lt;/sub&gt;) south of Iceland. These sample suites are associated with different tectonic settings: the Tonga subducting slab interacts with the Samoan plume beneath the Lau backarc basin, whereas the Mid-Atlantic Ridge interacts with the Icelandic plume at the Reykjanes Ridge. The contrasting tectonic settings provide a unique opportunity to decipher both the origin of N in plume mantle sources and the interaction of the plume mantle with other mantle components, including recycled material from subducting slabs and the DMM. Our results show that Rochambeau Bank (δ&lt;sup&gt;15&lt;/sup&gt;N from +1.3 ‰ to +2.8 ‰) and Reykjanes Ridge samples (δ&lt;sup&gt;15&lt;/sup&gt;N from -2.3 ‰ to +0.1 ‰) are both characterized by δ&lt;sup&gt;15&lt;/sup&gt;N values that are enriched relative to the DMM. Rochambeau Bank data are consistent with ternary mixing between the DMM (δ&lt;sup&gt;15&lt;/sup&gt;N = -5 ± 2 ‰; N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;3&lt;/sup&gt;He = 3.7 ± 1.2 × 10&lt;sup&gt;6&lt;/sup&gt;; N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;40&lt;/sup&gt;Ar* = 138±65), a subduction component from the adjacent Tonga slab with recycled N (δ&lt;sup&gt;15&lt;/sup&gt;N = ∼+3 ‰; N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;3&lt;/sup&gt;He = ∼10&lt;sup&gt;9&lt;/sup&gt;; N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;40&lt;/sup&gt;Ar* = ∼5 × 10&lt;sup&gt;6&lt;/sup&gt;), and a third component with δ&lt;sup&gt;15&lt;/sup&gt;N = ∼0 ‰, N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;3&lt;/sup&gt;He = ∼2 × 10&lt;sup&gt;5&lt;/sup&gt; and N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;40&lt;/sup&gt;Ar* = ∼40, which we attribute to the Samoan plume component enriched in primordial N. In contrast, Reykjanes Ridge data, combined with Iceland data, are consistent with ternary mixing among the DMM, plume components with recycled N (δ&lt;sup&gt;15&lt;/sup&gt;N from 0 ‰ to +6 ‰; N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;3&lt;/sup&gt;He = ∼10&lt;sup&gt;9&lt;/sup&gt;; N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;40&lt;/sup&gt;Ar* = ∼5 × 10&lt;sup&gt;6&lt;/sup&gt;) and primordial N (δ&lt;sup&gt;15&lt;/sup&gt;N from -2 ‰ to +2 ‰; N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;3&lt;/sup&gt;He = ∼2 × 10&lt;sup&gt;5&lt;/sup&gt;; N&lt;sub&gt;2&lt;/sub&gt;/&lt;sup&gt;40&lt;/sup&gt;Ar* = ∼40) endmembers in deep Icelandic mantle plumes. This is consistent with the presence of both recycled and primordial N being intrinsic to the Icelandic mantle plume. By integrating N data from other global plume-influenced samples (i.e., Society, Hawaii, and Central Indian Ridge), we show that the global dataset i","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"667 ","pages":"Article 119538"},"PeriodicalIF":4.8,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144605935","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":"Surface airflow patterns at a barchan dune field in Hellespontus Montes, Mars","authors":"Richard Love ,&nbsp;Derek W.T. Jackson ,&nbsp;Thomas A.G. Smyth ,&nbsp;Andrew Cooper ,&nbsp;Timothy Michaels ,&nbsp;Jean-Philippe Avouac","doi":"10.1016/j.epsl.2025.119536","DOIUrl":"10.1016/j.epsl.2025.119536","url":null,"abstract":"<div><div>Mobile barchan dunes are well-developed in a crater in the Hellespontus Montes region on Mars. Previous studies of their temporal evolution show that the barchans maintain their shape and migrate in a uniform pattern. Whereas barchans are typically associated with unidirectional wind regimes, the crater experiences seasonal changes in wind regime, driven by large-scale circulation patterns. Using a multi-scale modelling approach we demonstrate that the effect of upwind mesas are minimal to steering regional wind conditions, beyond the extent of the mesas themselves which limits the effect on the development and maintenance of barchan dunes further downwind. The results of high resolution CFD modelling showed individual barchan dunes had the capability to locally steer oblique wind flows along the orientation of the barchan dunes. We hypothesise that this ability of barchan dunes to ‘steer’ near surface local wind flows, combined with the uni-directional source of sediment at the site allows barchan morphology to persist in Hellespontus Montes, despite being subject to a range of incident wind directions.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"667 ","pages":"Article 119536"},"PeriodicalIF":4.8,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144596777","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":"Serpentinite dehydration-driven redox heterogeneity in cold subduction zone magmas","authors":"Zuxing Chen ,&nbsp;Fang-Zhen Teng ,&nbsp;Yuxiang Zhang ,&nbsp;Liping Qin ,&nbsp;Jinjing Huo ,&nbsp;Robert J. Stern ,&nbsp;Jia Liu ,&nbsp;Jing Lei ,&nbsp;Zhigang Zeng","doi":"10.1016/j.epsl.2025.119537","DOIUrl":"10.1016/j.epsl.2025.119537","url":null,"abstract":"<div><div>Serpentinite-derived slab fluids likely control the oxidation state of the sub-arc mantle, yet their oxidation state remains controversial. To address this issue, we report the first set of redox-sensitive chromium isotopic data for arc and back-arc basin lavas. Samples from the Mariana Arc and eastern Manus Basin have heavier Cr isotopic compositions (δ⁵³Cr = −0.13 to −0.18 ‰) than the MORB-like δ⁵³Cr values in the Mariana back-arc basin (−0.21 to −0.31 ‰). The δ⁵³Cr values correlate with Ba/La and V/Yb ratios, suggesting the control of slab-derived fluids on across-arc Cr isotope and oxygen fugacity variations. The Cr⁶⁺-bearing oxidized alkaline fluids released by serpentinite dehydration at sub-arc depths are enriched in heavy Cr isotopes. Their infiltration and reactions with the overlying mantle wedge facilitate the sub-arc oxidation of Fe²⁺ to Fe³⁺ and Cr²⁺ to Cr³⁺, resulting in heavy Cr isotopes and high oxygen fugacity in arc magmas. Oxidized fluids diminish beyond sub-arc depths due to the complete breakdown of antigorite, thus back-arc basin basalts have MORB-like δ⁵³Cr values and low oxygen fugacity. Our study suggests that Cr isotopes can provide critical insights into the role of serpentinite-derived fluids in redox heterogeneity in subduction-related magmas.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"667 ","pages":"Article 119537"},"PeriodicalIF":4.8,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144587578","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}