Earth and Planetary Science Letters最新文献

{"title":"Unraveling the key factors controlling active faulting in Tertiary and Quaternary sequences","authors":"Abhisek Basa ,&nbsp;Anita Torabi ,&nbsp;Juan Jiménez-Millán ,&nbsp;Francisco Juan García-Tortosa","doi":"10.1016/j.epsl.2025.119268","DOIUrl":"10.1016/j.epsl.2025.119268","url":null,"abstract":"<div><div>The effects of across-fault variation of mechanical properties and along-fault lithological heterogeneity on the seismicity of active faults is poorly understood. Moreover, the role of chemical processes on the mechanical behavior of active faults has not yet received sufficient attention. Such phenomena have more relevance, especially when faults juxtapose chemically reactive carbonate-dominated host rocks. In this study, we examine the key controls on active faulting by utilizing excellent outcrops of an intrabasinal strike-slip fault cutting across Tertiary and Quaternary sequences. We integrate structural, geomechanical and mineralogical investigations of faults and adjacent host rocks geographically exposed at different structural positions along the length of a 30 km-long, NE-SW-striking Galera Fault (GF) in Guadix-Baza basin, SE Spain. Our results show that fault and host rocks along the GF become carbonate-rich predominantly consisting of calcite towards NE. The thickness of sedimentary cover increases towards SW, where gypsum and phyllosilicate minerals are dominant. Calcite precipitation in fault rocks leads to reduction of porosity and significant enhancement of P-wave velocity (Vp), relative to the adjacent host rocks, and makes the fault zone more prone to seismic slip. On the contrary, phyllosilicates including clay mineral assemblages reduce the strength of the fault rocks and promote aseismic creep. The relationship between Vp and modified estimate of Brittleness Index used in this study indicate that the mineral assemblage of the fault as well as the adjacent host rocks influence seismicity. Our novel approach predicts more seismic activity towards the NE-part of GF due to dominance of calcite-rich rocks and proximity to the basement. This is validated by earthquake records in the studied area, which document shallow earthquakes concentrated towards the NE-part of GF. Thus, our study highlights the importance of adopting interdisciplinary approaches and understanding of the basin architecture controlling the distribution of host rocks to comprehend complex processes associated with active faulting.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"656 ","pages":"Article 119268"},"PeriodicalIF":4.8,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471224","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":"Volatile loss history of the Moon from the copper isotopic compositions of mare basalts","authors":"Marine Paquet ,&nbsp;Frederic Moynier ,&nbsp;Paolo A. Sossi ,&nbsp;Wei Dai ,&nbsp;James M.D. Day","doi":"10.1016/j.epsl.2025.119250","DOIUrl":"10.1016/j.epsl.2025.119250","url":null,"abstract":"<div><div>The abundances and isotopic signatures of volatile elements provide critical information for understanding the delivery of water and other essential life-giving compounds to planets. It has been demonstrated that the Moon is depleted in moderately volatile elements (MVE), such as Zn, Cl, S, K and Rb, relative to the Earth. The isotopic compositions of these MVE in lunar rocks suggest loss of volatile elements during the formation of the Moon, as well as their modification during later differentiation and impact processes. Due to its moderately volatile and strongly chalcophile behaviour, copper (Cu) provides a distinct record of planetary accretion and differentiation processes relative to Cl, Rb, Zn or K. Here we present Cu isotopic compositions of Apollo 11, 12, 14 and 15 mare basalts and lunar basaltic meteorites, which range from δ⁶⁵Cu of +0.55±0.01 ‰ to +3.94±0.04 ‰ (per mil deviation of the ⁶⁵Cu/⁶³Cu from the NIST SRM 976 standard), independent of mare basalt Ti content. The δ⁶⁵Cu values of the basalts are negatively correlated with their Cu contents, which is interpreted as evidence for volatile loss upon mare basalt emplacement, plausibly related to the presence Cl- and S-bearing ligands in the vapour phase. This relationship can be used to determine the Cu isotopic composition of the lunar mantle to a δ⁶⁵Cu of +0.57 ± 0.15 ‰. The bulk silicate Moon (BSM) is 0.5‰ heavier than the bulk silicate Earth (+0.07 ± 0.10 ‰) or chondritic materials (from -1.45 ± 0.08 ‰ to 0.07 ± 0.06 ‰). Owing to the ineffectiveness of sulfide segregation and lunar core formation in inducing Cu isotopic fractionation, the isotopic difference between the Moon and the Earth is attributed to volatile loss during the Moon-forming event, which must have occurred at- or near-equilibrium.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"656 ","pages":"Article 119250"},"PeriodicalIF":4.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463482","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":"The first Al-Cu-alloy-bearing unmelted micrometeorite suggests contributions from the disrupted ureilite protoplanet","authors":"Matthew J. Genge ,&nbsp;Matthias Van Ginneken ,&nbsp;Chi Ma ,&nbsp;Martin D. Suttle ,&nbsp;Natasha Almeida ,&nbsp;Noriko T. Kita ,&nbsp;Mingming Zhang ,&nbsp;Luca Bindi","doi":"10.1016/j.epsl.2025.119276","DOIUrl":"10.1016/j.epsl.2025.119276","url":null,"abstract":"<div><div>We report the discovery of Al-Cu-alloys within a coarse-grained micrometeorite from the Congo. Oxygen isotope ratios of the sample are consistent with a CV3 source, similar to the Khatyrka meteorite. The petrology of the micrometeorite is also similar to Khatyrka and testifies to the disequilibrium impact mixing between the CV3 parent body and a differentiated body, which was the source of the Al-Cu-alloys. The oxygen isotope composition, however, suggests either limited mixing with projectile silicates or a differentiated projectile with oxygen isotopes close to the CCAM. The most plausible origin of the Al-Cu-alloys is the desilication of an aluminous igneous protolith by hydrothermal activity under highly reduced conditions. We argue that the ureilite parent body is the most likely source for the projectile owing to its silicic magmatism, late-stage reduction and similar oxygen isotope ratios. Al-Cu-alloys can, thus, be found on the disrupted remnants of such protoplanets.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"656 ","pages":"Article 119276"},"PeriodicalIF":4.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463476","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":"Eastern equatorial Pacific paleo-productivity and carbon cycling during the late Pleistocene","authors":"C.T. Pallone ,&nbsp;J.F. McManus ,&nbsp;A.W. Jacobel","doi":"10.1016/j.epsl.2025.119255","DOIUrl":"10.1016/j.epsl.2025.119255","url":null,"abstract":"<div><div>A classical paradigm links enhanced marine biological production and resulting deep ocean carbon storage in the low latitude Pacific with reduced atmospheric CO₂ concentrations during Pleistocene ice ages. Subsequent studies of eastern equatorial Pacific paleo-productivity and associated processes do not unanimously characterize this system. Here, we present paleo-records of export production, sediment mass flux, dust flux, and bottom water oxygen derived from isotopes of U, Th, and Pa in marine sediments and synthesize existing paleo-records from a site in the eastern equatorial Pacific cold tongue over the last 160,000 years. Our results support the hypothesis that variations in marine export production were a consequence of changes in equatorial upwelling and in the nutrient concentrations of upwelled waters, not aeolian iron fertilization. We conclude that changes in marine export production in the eastern equatorial Pacific were not the principal driver of changes in local deep ocean carbon storage or atmospheric CO₂ across the late Pleistocene.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"656 ","pages":"Article 119255"},"PeriodicalIF":4.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463481","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":"Cooling history of the Bay of Islands Complex sub-ophiolitic metamorphic sole constrained by new mica 40Ar/39Ar thermochronology: Tectonic implications and comparison with the Semail sole","authors":"Weiyao Yan ,&nbsp;John F. Casey ,&nbsp;Laura E. Webb","doi":"10.1016/j.epsl.2025.119269","DOIUrl":"10.1016/j.epsl.2025.119269","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Metamorphic soles, including the Bay of Islands Complex (BOIC) sole in Western Newfoundland, are commonly observed welded to the base of large, obducted, flat-slab ophiolites throughout the world. The soles are characterized by similar inverted metamorphic field gradients with decreasing pressure-temperature (P-T) conditions recorded structurally-downward. Where studied in detail, they show that initial subcretion of near-peak P-T upper sections of the metamorphic soles is close in age to the formation of overlying ophiolite and that HT-MP portions of the soles cool from ∼800–900 °C to ∼300℃ within several million years (Myr). Previously the BOIC metamorphic sole has been interpreted to be generated near the age of ophiolite obduction. Recently, however, this interpretation has been challenged based on near peak-temperature U-Pb zircon age results of upper sole amphibolites. Here we present the first lower temperature &lt;sup&gt;40&lt;/sup&gt;Ar/&lt;sup&gt;39&lt;/sup&gt;Ar biotite and muscovite cooling ages (2σ) of 479.8 ± 2.1 (± 7.2) Ma and 478.7 ± 2.2 (± 7.4) Ma, respectively, for a biotite-garnet schist within amphibolite facies portions of the BOIC HT sole. These ages, combined with recent peak-temperature U-Pb dating results of zircon (ca. 489 Ma) and titanite also in HT amphibolites, indicate an initial apparent fast-cooling rate of ∼65–78℃/Myr followed by gradually deceasing rates, which, although slightly different, are comparable to other metamorphic soles, such as the extensively studied Semail ophiolite sole. The results show that the BOIC metamorphic sole cooled from initial HT subcretion (i.e., underplating) at ∼820℃ to ∼335℃ within ∼10 Myr (ca. 489–479 Ma). The subcretion of slab material and relatively rapid subsequent cooling of the BOIC HT-MP to LT-LP sole dominantly occurred during peri‑Laurentian Iapetus intra-oceanic subduction and well prior to 1) the initiation of ophiolite obduction at ca. 470 Ma, 2) the age of LT-HP eclogite formation in the subducted Laurentian continental crust at ca. 464 Ma, and 3) final ophiolitic allochthon emplacement by ca. 460–458 Ma. Because previously existing and self-sustaining subduction beneath the central Newfoundland Notre Dame arc was ongoing prior to the synchronous formation of the BOIC forearc ophiolite and sole, no new, large-scale, spontaneous subduction initiation event is required. A simpler ridge-trench-trench triple-junction with upper plate high-angle forearc spreading centers led to incremental induced subduction initiation beneath the thin BOIC forearc lithosphere as the ophiolite and HT sole formed near-synchronously. Lower temperature sole underplating occurred during progressive exhumation of the slab interface by slab flattening. This scenario is consistent with modern ophiolitic-type forearc analogs characterized by near-trench, high-angle forearc spreading centers with steeper initial slab interface dips and consequent near-trench forearc basalt and boninite magmatism lasting ∼10–15 My","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"656 ","pages":"Article 119269"},"PeriodicalIF":4.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463483","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":"Dislocation networks facilitate element diffusion in deformed garnet","authors":"B.V. Ribeiro ,&nbsp;C.L. Kirkland ,&nbsp;M.A. Finch ,&nbsp;C. Yakymchuk ,&nbsp;S.M. Reddy ,&nbsp;F.M. Faleiros ,&nbsp;K. Goemann ,&nbsp;I. Belousov","doi":"10.1016/j.epsl.2025.119271","DOIUrl":"10.1016/j.epsl.2025.119271","url":null,"abstract":"<div><div>Garnet is a key mineral in constraining the conditions and timing of metamorphism. Changes in its elemental composition can record distinct pressure (<em>P</em>) and temperature (<em>T</em>) conditions, and information on timing can be retained by its isotopic systems. Due to its mostly rigid behavior during deformation and high closure temperature for Lu–Hf diffusion, garnet geochemistry is interpreted to reflect garnet growth undisturbed by subsequent ductile deformation. However, nanoscale observations demonstrated element mobility into intracrystalline defects and suggested that garnet may not be as geochemically robust as commonly thought. Here, we assess the efficiency of dislocations in promoting grain-scale element mobility in garnet porphyroclasts naturally deformed under high-<em>T</em> conditions using a range of high-spatial resolution microstructural and chemical-isotopic techniques. We show that the development of low-angle subgrain boundaries in response to dislocation creep is insufficient to promote grain-scale element mobility. However, we find that Ca, Mg and trace elements (e.g., La, Ce, Lu, Hf, Sm, Ti, Zr and U) are mobilised on the grain-scale when the dislocation density exceeds the threshold to form a dislocation network. Although dislocation networks can enhance element mobility, the differences in <em>P–T</em> conditions from ‘low’- and ‘high-strain’ domains are negligible and unresolvable, reinforcing its geochemical robustness to estimate the prograde garnet growth conditions. Nevertheless, dislocation networks facilitate syn-kinematic diffusional Hf loss and Lu gain, demonstrating that garnet intracrystalline deformation can impact the Lu–Hf geochronometer. These observations indicate that isotopic resetting in garnet is more complex than previously assumed in rocks that underwent high-strain and temperature deformation.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"656 ","pages":"Article 119271"},"PeriodicalIF":4.8,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453292","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":"Thin basaltic regolith at the Chang'e-6 landing site","authors":"Sheng Gou ,&nbsp;Zongyu Yue ,&nbsp;Yangting Lin ,&nbsp;Kaichang Di ,&nbsp;Patrick C. Pinet ,&nbsp;Wei Yang ,&nbsp;Yuyang He ,&nbsp;Yi Chen ,&nbsp;Roberto Bugiolacchi ,&nbsp;Hengci Tian ,&nbsp;Honglei Lin ,&nbsp;Sen Hu","doi":"10.1016/j.epsl.2025.119266","DOIUrl":"10.1016/j.epsl.2025.119266","url":null,"abstract":"<div><div>The Chang'e-6 (CE6) mission is the first probe that has returned samples from the lunar farside. The sampling site is located on the southern mare basalt within the Apollo peak-ring impact basin. The Apollo basin itself lies within the clearly-recognized, largest and oldest South Pole–Aitken (SPA) basin on the Moon. Samples from the SPA are believed to be of great implications for multiple critical lunar science questions, such as impact chronology, impact basin formation processes, as well as stratigraphy and composition of lunar lower crust/upper mantle. Using available data sets from previous lunar missions, this study proposes a subsurface stratigraphy for the CE6 landing area based on crater morphologies and their excavation depths. The result revealed the thickness of the basaltic regolith at CE6 landing site is as thin as ∼1.6 m. Compositional data suggested the basalt-dominant samples (Mg#: ∼40) actually contain both intermediate-Ti (∼5.6 wt.% TiO₂) and low-Ti (∼3.3 wt.% TiO₂) basalts, with exotic Mg-suite clasts (Mg#: ∼70) as ejecta mainly from craters inside the Apollo basin. The remotely sensed compositional signatures indicated that the CE6 probe had sampled KREEP (an acronym for potassium, rare earth elements, and phosphorus)-poor (Th: ∼2 ppm) high-Al (∼14 wt. % Al₂O₃) materials. Since the mare basalts were products of thermal evolution and partial melting of the mantle, they are appropriate agents to study lunar farside thermal and geochemical evolution, and examine the nearside-farside crustal and volcanic dichotomies. Given that the sampling site is located in the margin of the proposed SPA transient cavity and melt pool, the exotic Mg-suite clasts in the CE6 samples may represent shallower crustal materials, which have the potential to provide valuable insights into lunar crustal composition and stratigraphy.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"655 ","pages":"Article 119266"},"PeriodicalIF":4.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429733","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 relationship between gravity anomalies and topography in the Pacific Ocean and its implications for flexural isostasy, mantle viscosity and dynamics","authors":"An Yang ,&nbsp;A.B. Watts ,&nbsp;Shijie Zhong","doi":"10.1016/j.epsl.2025.119246","DOIUrl":"10.1016/j.epsl.2025.119246","url":null,"abstract":"<div><div>Mantle dynamics in the interior and flexural isostasy of the lithosphere contribute to Earth's topography and gravity fields at different wavelengths, yet the actual transition wavelength between mantle dynamics and flexural isostasy and their relative contribution are not well quantified. A critical parameter in determining the transition is Earth's viscosity structure which controls both the response of the plates to loading and mantle flow models. Here, we present the first study to use the observed relationship between topography and the gravity anomaly (admittance) at wavelengths from ∼200 km to ∼5000 km in the Pacific Ocean to determine the nature of the transition and to constrain mantle viscosity based on combined plate flexure and mantle flow models. The Pacific Ocean, as well as global, data suggest a transition wavelength of ∼600 km such that flexural isostasy dominates at wavelengths shorter than ∼600 km, while mantle dynamics also contributes significantly to the topography and gravity for wavelengths longer than ∼600 km. Mantle flow models based on different seismic tomography models have been used to determine the main controls on the dynamic admittance at wavelengths between 600 and 5000 km for the Pacific. We find that the observed admittance is best explained by a temperature-dependent viscosity mantle and a weak asthenosphere. These results are used to separate the contributions of flexural isostasy and mantle dynamics at long wavelength and to examine their implications for the amplitude of dynamic topography in the Pacific Ocean.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"655 ","pages":"Article 119246"},"PeriodicalIF":4.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429734","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":"Extremely depleted radiocarbon impact on estimation of Glacial North Pacific Intermediate Water ventilation","authors":"Anqi Wang ,&nbsp;Zhengquan Yao ,&nbsp;Zhi Dong ,&nbsp;Xuefa Shi ,&nbsp;Yanguang Liu ,&nbsp;Sergey Gorbarenko ,&nbsp;Jianjun Zou ,&nbsp;Fengdeng Shi ,&nbsp;Xun Gong ,&nbsp;Alexander Bosin ,&nbsp;Yuriy Vasilenko ,&nbsp;Kunshan Wang ,&nbsp;Yazhi Bai ,&nbsp;Yijun Ren ,&nbsp;Weibin Zhang ,&nbsp;Han Feng ,&nbsp;Xinqing Zou","doi":"10.1016/j.epsl.2025.119254","DOIUrl":"10.1016/j.epsl.2025.119254","url":null,"abstract":"<div><div>Reconstructing the ventilation history of intermediate-depth Pacific Ocean remains challenging due to the influence of geologic carbon release, which biases radiocarbon (¹⁴C) ventilation age estimates. These uncertainties complicate the interpretation of past North Pacific Intermediate Water (NPIW) dynamics and its responses to climate variability. Here, we investigate NPIW changes during the last glaciation and subsequent deglaciation by analyzing benthic and planktonic ¹⁴C age offsets (B-P ¹⁴C age offsets), along with stable oxygen (δ¹⁸O_bf) and carbon isotope (δ¹³C_bf) records of benthic foraminifera in a sediment core from the southwestern Okhotsk Sea. The results indicate that B-P ¹⁴C age offsets were more than ∼9000 yrs during the last glaciation, suggesting a significant release of ¹⁴C-free geologic carbon, likely sourced from mixed gas clathrates in the southwestern Okhotsk Sea. These highly depleted ¹⁴C values have, therefore, led to an overestimation of ¹⁴C ventilation ages for Glacial North Pacific Intermediate Water in both the Okhotsk Sea and the Northwest Pacific during the Last Glacial Maximum (LGM). A compilation of δ¹⁸O_bf records from the North Pacific suggests that intermediate water formed in both the Okhotsk and Bering Seas during the LGM, extending to depths of at least ∼1590 m and ∼1000 m, respectively. Compared to the LGM, enhanced intermediate water formation in the Bering Sea during Heinrich Stadial 1 played an important role in intensifying NPIW, effectively flushing ¹⁴C-free geologic carbon from the Okhotsk Sea. This process might lead to a more uniform ventilation pattern at intermediate depths between the Northwest and Northeast Pacific. This study advances our understanding of NPIW evolution and reconciles previous discrepancies in ventilation reconstructions between the Northwest and Northeast Pacific during the LGM.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"655 ","pages":"Article 119254"},"PeriodicalIF":4.8,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429732","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":"Zirconium isotope evidence for crystal-melt segregation during high-silica granitic magma differentiation","authors":"Jionghui Wang ,&nbsp;Xi Zhang ,&nbsp;Zhaoxian Zhu ,&nbsp;Xinshui Wang ,&nbsp;Zaicong Wang ,&nbsp;Wen Zhang ,&nbsp;Fanghua Zhang ,&nbsp;Lanping Feng ,&nbsp;Shouhua Lai ,&nbsp;Qiushi Li ,&nbsp;Tao Luo ,&nbsp;Frédéric Moynier ,&nbsp;Zhaochu Hu ,&nbsp;Jing-Liang Guo","doi":"10.1016/j.epsl.2025.119251","DOIUrl":"10.1016/j.epsl.2025.119251","url":null,"abstract":"<div><div>Magma differentiation plays a crucial role in the chemical evolution of Earth's continental crust, with high-silica granites representing the product of extensive felsic magma differentiation. However, diagnostic evidence for crystal-melt segregation in felsic systems remains limited. This study investigates the potential of stable Zr isotopic composition as a novel tracer for high-silica magma differentiation processes, focusing on the Qitianling batholith and Yaogangxian pluton in the Nanling Range, South China, an area renowned for its large-scale distribution of high-silica granites (&gt;70 wt.% SiO₂). We present comprehensive analyses of both bulk-rock and in-situ zircon Zr isotopic compositions, integrated with zircon U-Pb-Hf isotopic and trace element data. Zircon Zr isotopic compositions show systematic correlations with zircon Hf contents and Zr/Hf ratios, demonstrating that Zr isotopic fractionation during zircon crystallization is driven by the preferential incorporation of light Zr isotopes in zircon. This relationship is further supported by correlations between bulk-rock δ^94/90Zr_IPGP values and Zr contents and Zr/Hf ratios, which indicate progressive zircon separation from residual melts during magmatic differentiation. As a result, highly fractionated granites display significant heavy Zr isotope enrichments, characterized by elevated δ^94/90Zr_IPGP values in both bulk rocks (0.48 ‰ to 1.05 ‰) and zircons (up to 2.39 ‰). In contrast, common granites with insignificant zircon-melt segregation display primitive bulk-rock Zr isotopic compositions (0.04 ‰ to 0.27 ‰) similar to the upper continental crust. These results indicate that effective physical crystal-melt segregation leads to a remarkable elevation in the bulk-rock and zircon δ^94/90Zr_IPGP values of highly fractionated granites compared to those of common granites. Geochemical modeling suggests that &gt;60 % segregation of zircon is required to account for the heavy Zr isotopic compositions in highly evolved granites. Furthermore, the high Zr isotopic values in zircon correlate with enriched U, W, Sn, and other incompatible elements, implying that Zr isotopic composition could serve as an indicator for mineralization potential associated with felsic magma differentiation.</div></div>","PeriodicalId":11481,"journal":{"name":"Earth and Planetary Science Letters","volume":"655 ","pages":"Article 119251"},"PeriodicalIF":4.8,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420061","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}