Lithos最新文献

{"title":"The ultrahigh-temperature porphyritic charnockites in the eastern Khondalite Belt, North China Craton: Implications for two-stage of anatexis events","authors":"Tongjun Liu ,&nbsp;Weimin Li ,&nbsp;Yongjiang Liu ,&nbsp;Wei Jin ,&nbsp;Yingli Zhao ,&nbsp;Jinhui Gao","doi":"10.1016/j.lithos.2025.108272","DOIUrl":"10.1016/j.lithos.2025.108272","url":null,"abstract":"<div><div>Igneous charnockites are key components of many high-grade metamorphic terranes and provide crucial insights into crustal anatexis and crust-mantle interactions in the deep crust. However, the petrogenesis of ultrahigh-temperature (UHT) peraluminous charnockites—a distinctive subgroup of igneous charnockites—remains poorly understood because of their limited exposure. In this study, we investigate the UHT porphyritic charnockites from the Jining terrane in the eastern Khondalite Belt of the North China Craton, using petrography, mineralogy, geochemistry, geochronology, and EBSD fabric analyses to elucidate their petrogenesis and relationship with UHT metamorphism. The porphyritic charnockites are characterized by 40–50 vol% of partially interlocking, subhedral to anhedral phenocrysts of K-feldspar, plagioclase, and quartz (3–8 mm), commonly exhibiting embayed or subrounded margins. The remaining ∼50–60 vol% finer-grained interstitial matrix are composed of euhedral to subhedral plagioclase, quartz, K-feldspar, and orthopyroxene. Geochemically, these rocks are strongly peraluminous (ASI = 1.09–1.42) and enriched in high ferromagnesian components (TFeO + MgO = 8.28–10.87 wt%). Both macro- and microscopic structures indicate that the porphyritic charnockites underwent significant crystal accumulation and melt loss/extraction processes. Ternary feldspar thermometry reveals that matrix minerals crystallized at higher temperature condition (950–1000 °C) than the early-formed phenocrysts (850–900 °C), reflecting a complex thermal evolution. Zircon U<img>Pb dating, combined with previous data, reveals two-stage anatectic events at approximately 1.95 Ga and 1.92 Ga. These results suggest that the porphyritic charnockites formed initially through the accumulation of anatectic magma crystals, where were later remelted under UHT conditions. Consequently, the Jining terrane underwent multistage anatexis, with melt-bearing conditions sustained over tens of millions of years. These findings provide new insights into the processes of crustal anatexis and the evolution of the UHT orogenic lower crust.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108272"},"PeriodicalIF":2.5,"publicationDate":"2025-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochronology and petrogenesis of alkaline rocks from the Peshawar Plain Alkaline Igneous Province, NW Himalaya, Pakistan: Implications for rare metal mineralization and geodynamic settings","authors":"Amjad Hussain ,&nbsp;Kui-Dong Zhao ,&nbsp;Hafiz U. Rehman ,&nbsp;Qian Li ,&nbsp;Syed Asim Hussain ,&nbsp;Zahid Hussain ,&nbsp;Tehseen Zafar ,&nbsp;Sakine Moradi ,&nbsp;David Widory","doi":"10.1016/j.lithos.2025.108271","DOIUrl":"10.1016/j.lithos.2025.108271","url":null,"abstract":"<div><div>Alkaline rocks of the Peshawar Plain Alkaline Igneous Province (PPAIP) constitute a major magmatic unit within the Indian plate in northwestern Pakistan. However, their tectonic settings, petrogenesis, and potential for associated rare metal mineralization remain poorly constrained. In this study, we present U<img>Pb zircon ages, mineral and whole-rock geochemical data, and Nd<img>Hf isotope compositions for the Baru granite and its associated pegmatite, providing new insights into their origin. Zircon U<img>Pb dating of the Baru granite and the pegmatite yielded crystallization ages of 270.6 ± 1.7 Ma and 270.3 ± 1.5 Ma, respectively. Zircon grains exhibit positive ɛ_Hf(t) values, ranging from +4.1 to +7.3 for the Baru granite and from +5.2 to +10.0 for the pegmatite. The nearly identical ages and highly similar Hf isotope compositions indicate a co-magmatic origin for the granite and the pegmatite. Geochemically, the Baru granite is characterized by high SiO₂, Rb, Nb, U, and Ta contents, low Yb/Ta, Y/Nb ratios, and positive bulk-rock ɛ_Nd(t) values (+2.8 to +4.5). These features are consistent with fractionated anorogenic A-type granites derived from an OIB-like mantle source. Trace element compositions of zircons from the granite and the pegmatite exhibit systematic evolutionary trends, including increasing concentrations of HREEs, Hf, U, Y, Nb, and Ta, coupled with decreasing Eu anomalies and Ti concentrations. These trends strongly suggest that prolonged fractional crystallization of an alkaline magma, progressing from the granite to the pegmatite, was responsible for the enrichment of rare metals in the residual pegmatitic melt. The Baru granite shares similar emplacement ages and Hf<img>Nd isotope compositions with other Permian alkaline rocks in the NW Himalaya, southern Qiangtang, and Tibet. This spatial and temporal correlation implies that these alkaline rocks formed within a large-scale extension regime across the Tethys realm. This early Permian magmatic event was likely triggered by a mantle plume, which played an active role during rifting along the northern margin of Gondwana.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108271"},"PeriodicalIF":2.5,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disseminated layering or syn-shearing multi-phase petrogenetic model of Cu-Ni-PGE-bearing Khudolaz Differentiated complex in the Southern Urals: A case study of collisional ultramafic-mafic magmatism","authors":"I.R. Rakhimov ,&nbsp;E.L. Kunakkuzin ,&nbsp;A.V. Vishnevskiy ,&nbsp;N.G. Soloshenko ,&nbsp;D.V. Kiseleva","doi":"10.1016/j.lithos.2025.108267","DOIUrl":"10.1016/j.lithos.2025.108267","url":null,"abstract":"<div><div>The Khudolaz Differentiated Complex (KDC) with Cu-Ni-PGE mineralization is located in the central part of the Southern Urals. Its geology is marked by numerous minor intrusions of diverse composition from schriesheimites to diorite scattered over a wide area and corresponding to individual horizons within larger layered massifs. We analyzed the morphologies and structural-geological constraints of the intrusion emplacement. Based on the mineralogical, geochemical and Sr-Nd isotopic data, we developed a petrogenetic model of KDC that explains the disseminated layering. According to our model a deep-seated magma chamber formed beneath the Khudolaz Trough within a local extension zone at the boundary between the ophiolitic mélange and continental metasedimentary complexes during the <em>syn</em>-collisional shearing. The magma ascended from a deep-seated chamber through a network of syn-shearing faults. The process was accompanied by assimilation of diverse country rocks composing the continental crust beneath the Magnitogorsk island-arc terrane. Smaller intermediate chambers developed in the upper crust, facilitating further melt differentiation. A fault network constraining emplacement of the intrusions occurred about 330 Ma ago during the convergence of the Kazakhstania and Laurussia paleocontinents and their surrounding terranes. A <em>syn</em>-collisional thrust instigated the deformation the deep-seated fractionating chamber, driving the extrusion of its individual horizons into the upper crustal level. As a result, a schriesheimite belt formed, which origin cannot be explained solely by processes of intra-chamber differentiation or finger-like magma flow. Melt differentiation in deep-seated chamber and intermediate chambers was associated with olivine cumulus formation and sulfide precipitation following early sulfide-silicate immiscibility. At the advanced stage of the magmatic system evolution, the melt became enriched in water under crustal conditions, promoting extensive formation of taxitic gabbro and pegmatites. The Carboniferous volcano-plutonic belt of the Magnitogorsk terrane could have formed by the emplacement of oncoming asthenospheric diapirs into tectonic windows. This process was initiated by slab break-off beneath the Magnitogorsk arc and continued after subsequent slab break-off beneath the East Uralian continental block.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108267"},"PeriodicalIF":2.5,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochronological and geochemical insights into episyenite metasomatic overprint in the Proterozoic Suomenniemi rapakivi granite complex (Finland)","authors":"Adam Abersteiner ,&nbsp;O. Tapani Rämö ,&nbsp;Alkis Kontonikas-Charos ,&nbsp;Melissa Kharkongor ,&nbsp;Nikolaos Karampelas ,&nbsp;Sarah E. Gilbert ,&nbsp;Ben Wade ,&nbsp;Karolina Ambroziak-Murzyn ,&nbsp;Jarred C. Lloyd ,&nbsp;Christoph Beier ,&nbsp;Stijn Glorie","doi":"10.1016/j.lithos.2025.108269","DOIUrl":"10.1016/j.lithos.2025.108269","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Rapakivi granites from the late Paleoproterozoic Suomenniemi Complex (south-eastern Finland) experienced pervasive localised metasomatism via interaction of high-temperature, oxidising peralkaline fluids and granite along dyke-like zones, resulting in the formation of episyenite bodies. To constrain the timing and conditions of episyenite formation, we combine in-situ U&lt;img&gt;Pb zircon, U&lt;img&gt;Pb and Lu&lt;img&gt;Hf apatite, and U&lt;img&gt;Pb titanite geochronology with petrography and mineral chemistry from four episyenite bodies. Zircon yields U&lt;img&gt;Pb ages coeval with crystallisation of the ca. 1644 Ma granite, preserving the igneous protolith age, whereas U&lt;img&gt;Pb ages from hydrothermally modified zircon (1635.1 ± 2.7 Ma; 1627.8 ± 6.3 Ma) and apatite (1611.6 ± 9.5 Ma; 1630 ± 19 Ma), along with hydrothermal titanite (1603 ± 43 Ma; 1623 ± 30 Ma) record younger ages, reflecting variable degrees of disturbance of the U&lt;img&gt;Pb system and indicating that episyenite formation post-dated granite emplacement. Apatite Lu&lt;img&gt;Hf ages (1648 ± 30 Ma; 1643 ± 41 Ma) and some titanite U&lt;img&gt;Pb ages (1646 ± 12 Ma; 1642 ± 62 Ma) overlap with the host granite but their large uncertainties preclude confident attribution to either magmatic crystallisation or subsequent metasomatism. Collectively, these data indicate that episyenitisation postdated granite emplacement and was likely driven by regional thermal perturbations linked to the emplacement of the ∼1630 Ma Wiborg Batholith.&lt;/div&gt;&lt;div&gt;Petrographic and mineral chemistry analyses of zircon, apatite, and titanite indicate that hydrothermal alteration of the protolith was highly variable, both between episyenite bodies and even over small metre-scale intervals within individual bodies. This is evident in zircon, where different areas of high intensity hydrothermal alteration under high temperature and oxidising conditions resulted dissolution and reprecipitation of zircon. Apatite in the host granite was likely recrystallised during episyenitisation, as evidenced by textural modification and younger U&lt;img&gt;Pb ages. Titanite is an accessory mineral found exclusively within the episyenite bodies and is absent in the surrounding granite protolith. It commonly occurs as inclusions in mafic mineral aggregates or as rims around Fe&lt;img&gt;Ti oxides (magnetite, ilmenite), suggesting a hydrothermal origin associated with episyenitisation and crystallisation under oxidising conditions. Variations in the major (Al, Fe, Ti, F) and trace element (light REE, Nb) chemistry of titanite and Zr-in-titanite thermometry (660–875 °C) further indicate differences in hydrothermal fluid composition and temperatures during titanite formation across different episyenite bodies. These findings, along with the overlapping ages of hydrothermal titanite and the host protolith, suggest that the episyenites in the Suomenniemi Complex formed by fluid-rock interaction, either shortly after consolidation of the main granite sequence of the complex and/o","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108269"},"PeriodicalIF":2.5,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 Cenozoic magmatic heterogeneity in the Alborz rear-arc: Spatial variation from enriched to juvenile signatures","authors":"Ghasem Ghorbani ,&nbsp;Fatemeh Sepidbar ,&nbsp;Hadi Shafaii Moghadam ,&nbsp;Zhaochu Hu ,&nbsp;Massimo Chiaradia ,&nbsp;Richard M. Palin","doi":"10.1016/j.lithos.2025.108268","DOIUrl":"10.1016/j.lithos.2025.108268","url":null,"abstract":"<div><div>Across-arc geochemical variations in igneous rocks are common in magmatic belts that form at convergent margins, but the geological processes responsible are unclear. To investigate this, we acquired new whole-rock major and trace element data, coupled with Sr–Nd–Pb isotopic ratios, zircon Hf isotopes, and U<img>Pb geochronology for three intermediate and felsic intrusions in the Baghu, Chalu and Gandi regions of the Moallemen magmatic complex, NE Alborz rear-arc. These were compared to data from well-exposed Early Cenozoic Alborz rear-arc igneous rocks in northeastern and northwestern Iran. The Chalu intrusions are mainly monzonite, quartz-monzonite, whereas the Baghu and Gandi intrusions are granodiorite and granite, respectively. U<img>Pb zircon crystallization ages of 49.9 ± 0.74 and 46.3 ± 0.82 Ma for the Chalu intrusions indicate that they are slightly older than the Baghu granodiorite (41.2 ± 2.3 Ma) and Gandi granite (42.2 ± 0.99 Ma). The Chalu monzonite and quartz-monzonite rocks display relatively higher LILE/HFSE (Ba/Th: 60–167) but similar LILE/LREE (Ba/La: 17–21) values to those of the Baghu and Gandi intrusions (Ba/Th: 27–54; Ba/La: up to 25). All three units show the same Sr–Nd–Pb isotopic compositions, having same radiogenic Sr (⁸⁷Sr/⁸⁶Sr, 0.70400–0.70425) and Pb (²⁰⁶Pb/²⁰⁴Pb, 18.50–18.53; ²⁰⁷Pb/²⁰⁴Pb, 15.58–15.59; ²⁰⁸Pb/²⁰⁴Pb, 38.56–38.63), Nd (¹⁴³Nd/¹⁴⁴Nd, 0.51272–0.51295) and zircon Hf (+7.2 to +11.4) isotopic compositions. Modeling of Sr<img>Nd isotopes suggests that these magmas were generated by the interaction of mantle-derived melts with lower continental crust through a series of assimilation-fractional crystallization (AFC) processes during ascent in the NE Alborz rear-arc. Published major and trace element data, bulk rock εNd(t) and zircon εHf(t) isotope data across the Alborz rear-arc show that melts of enriched lithospheric mantle and subducted slab-derived experienced less crustal interaction in the central and NW Alborz rear-arc than in the NE Alborz rear-arc. This variation reflects differences in subduction dynamics, crustal thickness, and mantle wedge processes along the Alborz rear-arc, indicating the utility of magmatic complexes for deciphering ancient tectonic processes. This work also settles a long-standing debate about the geodynamic evolution of the Alborz rear-arc, showing that a compressive to extensional tectonic regime existed during the Arabia–Eurasia collision.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108268"},"PeriodicalIF":2.5,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical constraints on origin of high-silica granite and volcanic-plutonic connection: An example from Ningwu volcanic basin, Eastern China","authors":"Jiancheng Xie,&nbsp;Sujuan Zhou,&nbsp;Lin Qian,&nbsp;Qian Feng,&nbsp;Liu Yang,&nbsp;Shan Huang,&nbsp;Quanzhong Li,&nbsp;Jianmin Liu,&nbsp;Jun Yan","doi":"10.1016/j.lithos.2025.108270","DOIUrl":"10.1016/j.lithos.2025.108270","url":null,"abstract":"<div><div>High-silica granites (HSGs), commonly associated with felsic volcanic rocks, preserve key information on origin and differentiation of the continental crust through geological time. However, a typical distribution area of Cretaceous HSGs and felsic volcanic rocks in southeast China, origin of the HSGs, their volcanic-plutonic connection, and the causes of mineralization differences remain poorly constrained. This study systematically presents petrological, zircon U<img>Pb geochronological, and whole-rock major and trace element, whole-rock Sr-Nd-Pb, and zircon Hf isotopic data of the HSGs in Ningwu volcanic basin, eastern China. Zircon U<img>Pb ages indicate that the HSGs (SiO₂ = 73.5–76.4 wt%) are coeval (ca. 130–128 Ma) with the low-silica granites and volcanic rocks (60.2–70.2 wt% SiO₂) in the Ningwu basin. The similar Nd<img>Hf isotopes, high radiogenic Pb isotopes, and identical trace elemental evolution trends suggest that their parental magmas possibly were originated from partial melting of pre-existing Paleo-Mesoproterozoic accreted crust which was modified and replaced by Cretaceous enriched basic magma involving limited subducted sediments. The HSGs studied have low Eu/Eu* (0.45–0.67) and Zr/Hf (26.9–29.6) ratios, low Eu (0.33–0.83 ppm) and Ba contents (47.6–714 ppm). Combined with the corrosion structures of quart and K-feldspar, these trace-element variations (whole-rock and zircon) and geochemical features suggest that the Ningwu HSGs are the extracted melt of a crystal mush. The low-silica granite porphyries and volcanic rocks have high Eu/Eu* (&gt; 0.7) and Zr/Hf (&gt; 30) ratios, and high Eu (mainly &gt;0.80 ppm) and Ba contents (mainly &gt;800 ppm), showing a cumulate residue. We propose that injection of mantle-derived basaltic magma rejuvenated partial melting of the pre-existing Paleo-Mesoproterozoic crust, generating intermediate to felsic magma. Progressive crystallization produced a crystal-rich mush, which evolved into a shallow silicic magma chamber. The extracted crystal-poor high-silica melts ascended to shallower crustal levels, forming the Ningwu HSGs, whereas the residual silicic cumulates crystallized as the low-silica granites and volcanic rocks. Comprehensive discriminant analysis further suggests that magma source and evolutionary processes likely were key controls on iron mineralization, while high tungsten contents (580–1620 ppm) in the HSGs reflect strong magmatic fractionation in the Ningwu region.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108270"},"PeriodicalIF":2.5,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contrasting geochemistry of apatite from the Jurassic W- and Sn-mineralized granites in the Qitianling field, Nanling Range, South China","authors":"Hongfei Di ,&nbsp;Yong-Jun Shao ,&nbsp;David Chew ,&nbsp;Rui-Chang Tan ,&nbsp;Han Zheng ,&nbsp;Yong Liang ,&nbsp;Wen-Jie Fang ,&nbsp;Yi-Qu Xiong","doi":"10.1016/j.lithos.2025.108264","DOIUrl":"10.1016/j.lithos.2025.108264","url":null,"abstract":"<div><div>Tungsten and tin are vital to human society, however, their spatio-temporal decoupling mechanisms remain debated. The Qitianling batholith in the Nanling Range hosts the Xintianling W deposit in the northeast and the Furong Sn deposit in the southwest, making it an ideal place to study the spatial separation of Jurassic W-Sn deposits. This study analyzes apatite geochemistry and Nd isotopes in the Xintianling W-mineralized granites, comparing them with published data of the Qitianling Sn-mineralized granites. Apatite in the Qitianling Sn-mineralized granites exhibits ε_Nd(t) values of −8.19 to −5.88 with T_DM2 ages ranging from 1615 to 1428 Ma, while apatite in the Xintianling W-mineralized granites displays clustered ε_Nd(t) values of −9.27 to −8.06 with T_DM2 ages ranging from 1706 to 1608 Ma. The overlapping T_DM2 ages suggest that both were derived from the partial melting of Paleo- to Mesoproterozoic crustal materials, with the addition of mantle-derived melts in the Qitianling granites. The Sr and ΣREE contents, along with (La/Sm)_N, (La/Yb)_N, and Eu/Eu* ratios of apatite indicate that the Qitianling granites underwent significant feldspar and hornblende fractional crystallization, while the Xintianling granites experienced significant feldspar, monazite, and allanite fractional crystallization. Apatite in the Qitianling granites has higher FeO contents and lower MnO, SO₃ contents and Eu/Eu* ratios than apatite in the Xintianling granites, suggesting more reducing conditions for the former. The Qitianling Sn-mineralized granites have lower F and SO₃ contents and higher Cl contents than the Xintianling W-mineralized granites. Therefore, source magma chemistry and its subsequent magmatic evolution, along with intensive physical-chemical variables together play a significant role in controlling the spatial segregation of W-Sn deposits. Supervised orthogonal partial least squares discriminant analysis (orthoPLS-DA) was used to evaluate the suitability of apatite as a discriminator for the decoupling of W-Sn deposits. Results reveal that LREE, Mn, Hf, Nd, and Eu are the key elements contributing to the discrimination of apatites between the Qitianling Sn and Xintianling W granites, which can be a discriminator for decoupling of W-Sn deposits in the Nanling Range and beyond in South China.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108264"},"PeriodicalIF":2.5,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mineralogy and provenance of the Chang'e-6 shoveled lunar samples","authors":"Shanna Xue ,&nbsp;Wenlei Song ,&nbsp;Zhuang Guo ,&nbsp;Yuqi Qian ,&nbsp;Kangjun Huang ,&nbsp;Chao Zhang ,&nbsp;Qian Liu ,&nbsp;Xiaojun Wang ,&nbsp;Le Qiao ,&nbsp;Qian Chen ,&nbsp;Donghai Zhang ,&nbsp;Lihui Chen ,&nbsp;Honglin Yuan ,&nbsp;Guochun Zhao","doi":"10.1016/j.lithos.2025.108265","DOIUrl":"10.1016/j.lithos.2025.108265","url":null,"abstract":"<div><div>Lunar regolith develops through continuous gardening resulting from various space weathering processes. The Chang'e-6 (CE-6) mission landed on the lunar farside within the geologically complex South Pole-Aitken basin that was modified by impact events. Soil collected from this site preserves a detailed record of lunar geological evolution. The fine-grained regoliths reflect extensive mechanical fragmentation and mixing, and they closely match the landing area's average mineralogy. This study provides a statistical evaluation of the mineralogy, bulk geochemistry, and provenance of the CE-6 fine-grained soils (70,437 particles) using automated quantitative mineralogy and mineral chemistry analysis. The examined particles, mostly ≤30 μm in size, comprise approximately 93.5 vol% of mare basalts (plagioclase: 27.5 %; glass: 32.3 %; pyroxene: 28.2 %; olivine: 0.7 %; ilmenite: 1.9 %; Si-rich phase: 1.2 %) and approximately 6.5 vol% of exotic non-mare components. Exotic components consist mainly of anorthite (An ≥ 95) and pyroxene (En &lt; 50) from ferroan anorthosite (FAN) (0.9 %; 0.3 %), low-Ca pyroxene (Wo ≤ 5, 1.2 %, norite), Mg-rich pyroxene (En ≥ 50, 1.3 %), equivalent plagioclase from Mg-suite clast (∼2.5 %) and magnesian olivine from the troctolite and mantle materials (Fa ≤ 20, 0.3 %). Compared to Chang'e-5 basalts, the CE-6 samples show higher glass abundance and elevated Al₂O₃, CaO, and Mg^#, but lower FeO levels. These differences suggest a longer history of impact gardening with more exotic non-mare components at the CE-6 sampling site. This study provides the first direct and statistically robust mineralogical evidence constraining the provenance of CE-6 soils, supporting and refining previous interpretations of lunar regolith evolution.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108265"},"PeriodicalIF":2.5,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Raichur schist belt, eastern Dharwar Craton, India: A geochemical analogue of western Aleutian arc","authors":"Tarun C. Khanna ,&nbsp;D. Srinivasa Sarma","doi":"10.1016/j.lithos.2025.108263","DOIUrl":"10.1016/j.lithos.2025.108263","url":null,"abstract":"<div><div>Oblique convergence of the Pacific plate beneath the North American plate produced the western Aleutian arc. The western Aleutian basalts, and to a large extent, the Mg-andesites concur with partial melting of a mantle source infused with subducted slab-derived melts. By analogy, MORB-like depleted rare earth element patterns (La_N/Yb_N ≤ 1) and arc-like incompatible trace element enrichments relative to high field strength elements Ba/Nb &gt; 25 in the Raichur basalts are consistent with their genesis in a setting, similar to the modern-day intraoceanic arcs. Geochemical attributes of the Aleutian arc lavas preclude melting of pelagic sediment during the course of subduction. By analogy, the radiogenic initial εNd_(<em>t</em> _{=2.7 Ga)} = +2.05 to +3.15 isotopic compositions in the Raichur basalt-andesite suite preclude crustal contamination. The rare earth element patterns and Ba-La-Yb systematics between the Aleutian arc lavas and the Raichur belt are identical, and concur with the absence of subducted sediment in their mantle source. A hypothetical slab-melt + mantle wedge interaction model, discounting sediment melt, can explain the genesis of Raichur Mg-andesites, which is identical to that proposed for the western Aleutians. Apparently, the geochemical process of arc magma genesis recorded in the Neoarchean greenstone belts of the Dharwar Craton resembles Phanerozoic-style magmatism in the Cenozoic oceanic arcs. Consequently, the mechanism of continental crust formation has neither changed significantly over time nor across the Earth.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108263"},"PeriodicalIF":2.5,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145119395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of dunites within the Moho transition of the Samail Ophiolite: A study using drill cores obtained by of the Oman Drilling Project","authors":"Sven Merseburger ,&nbsp;Felix Marxer ,&nbsp;Ingo Horn ,&nbsp;Dieter Garbe-Schönberg ,&nbsp;Ulrike Westernströer ,&nbsp;Sandrin T. Feig ,&nbsp;Andreas B. Kaufmann ,&nbsp;Francois Holtz ,&nbsp;Jürgen Koepke","doi":"10.1016/j.lithos.2025.108261","DOIUrl":"10.1016/j.lithos.2025.108261","url":null,"abstract":"<div><div>Here we investigate the genesis of the Moho transition zone (MTZ), sandwiched between mantle and crustal rocks of the Samail ophiolite, through a petrological and geochemical study of cores taken by the Oman Drilling Project (Oman DP). The MTZ drilled, comprises a 150 m-thick dunite horizon that is practically pure dunite in the upper 90 m but cut by several gabbroic intrusions in the lower part. The dunite is nearly completely altered to serpentinite, with only Cr-spinel as the relict primary phase. We interpret the entire MTZ as having formed through reactive interactions between MORB melts and shallow mantle peridotite. The key process is the dissolution of orthopyroxene and concomitant precipitation of olivine during porous flow of ascending MORB melts.</div><div>In the lower part of the MTZ, evolution trends in Cr-spinel chemistry are absent, precluding crystal fractionation processes. Instead, the presence of relict clino- and orthopyroxene in the serpentinized dunites, exhibiting characteristic mantle deformation, associated with elevated “spoon”-shaped bulk REE patterns, are interpreted as signatures of replacive dunites formed by MORB/harzburgite interaction. In contrast, relict spinels of the upper pure dunite zone at the top of the MTZ show systematic compositional variations with depth, interpreted to have resulted from differentiation of a primitive MORB melt. Although spinel compositions are well correlated with incompatible element concentrations, including Ti and V, there is very poor or non-existent correlation of compatible elements, such as Ni and Cr. These are diagnostic signatures of “reactive fractionation” according to <span><span>Collier and Kelemen (2010)</span></span>, where compatible element concentrations are buffered by diffusive interaction with the surrounding harzburgite, whereas the decreasing magma mass leads to the accumulation of incompatible elements in the remaining melt.</div><div>This upper dunite zone could correspond to the “missing cumulates”, necessary to model the evolution of the Oman bulk crust, which shows a too-evolved composition, assuming it was formed from a typical primitive parental MORB.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"516 ","pages":"Article 108261"},"PeriodicalIF":2.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}