Journal of Asian Earth Sciences最新文献

{"title":"Phosphogenesis of Kakul Garlaniyan phosphorites during the early Cambrian in northeastern Pakistan","authors":"Massam Ali ,&nbsp;Haifeng Fan ,&nbsp;Danish Khan ,&nbsp;Fang Zhang ,&nbsp;Ishfaq Ahmad ,&nbsp;Muhammad Asif Sherliyat ,&nbsp;Yuhan Ma ,&nbsp;Jibran Hussain ,&nbsp;Hanjie Wen","doi":"10.1016/j.jseaes.2025.106927","DOIUrl":"10.1016/j.jseaes.2025.106927","url":null,"abstract":"<div><div>The largest phosphogenesis event in Earth’s history occurred during the Precambrian-Cambrian transition, characterized by the formation of extensive global phosphorite deposits. One of the most notable examples is the Kakul Garlaniyan phosphorite, located at the topmost part of the Sirban member of the Abbottabad Formation in the Hazara region of northeastern Pakistan, dating to the Early Cambrian (∼541 Ma, Terreneuvian). Despite its significance, limited studies have addressed the origin and formation processes of the phosphorite deposits in this area. To enhance our understanding, we conducted petrographic and geochemical analyses on samples from three intercalated phosphorite layers within the Sirban Member. The phosphorite comprises both primary and reworked grains, with quartz supplied by terrestrial input. The grains are derived from a marine origin, enriched by upwelling of nutrient-rich bottom seawater. Additionally, the radiogenic ⁸⁷Sr/⁸⁶Sr isotope ratios (0.7113–0.7129) indicate terrestrial flux to the inner shelf environment through the chemical weathering of continental rocks. Rare earth and yttrium (REY) patterns exhibit a seawater-like, post-Archean Australian Shale (PAAS)-normalized REY distribution, with significant negative Ce/Ce* anomalies (0.40–0.54) and super-chondritic Y/Ho ratios (∼50–60), indicating a hydrogenous origin and supporting oxic conditions. The (La/Yb)_N and (La/Sm)_N ratios in Kakul Garlaniyan phosphorite layer suggest REY adsorption during early diagenesis, consistent with modern seawater conditions. Based on these findings, we propose a phosphogenesis depositional model: phosphorite formed via upwelling and reworking rather than hydrothermal activity under mainly oxic (with rarely anoxic conditions) and abiotic conditions. Winnowing and transgression events transformed pre-existing phosphate mud into reworked grains, occurring in the absence of microbial mediation. These findings provide new insights into the processes governing phosphorite formation during the Early Cambrian period in the Abbottabad region.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106927"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145808546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraints of basement geometry and supra-salt cohesion on deformation of salt-bearing fold-and-thrust belts: a discrete-element study","authors":"Huaibo Zhao ,&nbsp;Shuping Chen ,&nbsp;Timothy Chris Schmid ,&nbsp;Haowei Yuan ,&nbsp;Weijia Zhan ,&nbsp;Fan Wang","doi":"10.1016/j.jseaes.2025.106904","DOIUrl":"10.1016/j.jseaes.2025.106904","url":null,"abstract":"<div><div>Salt-bearing fold-and-thrust belts (FTBs) in foreland basins exhibit complex structural architectures, primarily governed by the interplay among basement geometry, supra-salt mechanical strength, and the detachment behavior of intervening salt layers. However, the respective roles of basement surface geometry and supra-salt cohesion in controlling deformation localization, thrust segmentation, and fold development remain poorly constrained, particularly in regions with limited subsalt seismic imaging. To address this gap, we conducted two-dimensional discrete element method (DEM) simulations to systematically assess how variations in basement surface geometry and supra-salt cohesion influence the structural evolution of salt-bearing FTBs. The results show that lateral variations in basement morphology produce significant heterogeneity in salt layer thickness, thereby strongly influencing salt particle rearrangement and deformation localization. Redistribution of salt particles from thick to thin zones leads to compression and uplift in the overburden, while reverse movement induces extension and subsidence. A relatively low supra-salt cohesion promotes more rapid deformation front propagation, increased fold density, and more frequent salt piercement, whereas a relatively high cohesion delays deformation front propagation and favors fewer but higher-amplitude folds and enhanced thrust faulting. Comparisons with representative natural examples demonstrate that the models broadly capture the main structural features of salt-related FTBs at a regional scale, including large-scale thrust systems and salt-cored folds. Overall, our findings highlight that basement relief and supra-salt cohesion are first-order controls on structural evolution in compressional salt-bearing systems, thereby enhancing the understanding of deformation localization, thrust segmentation, and fold development.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106904"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genesis and evolution of ore-forming fluids in the Liushashan Mo deposit, Inner Mongolia: Insights from fluid inclusions and C–H–O–S isotopes","authors":"Shuopu Yuan ,&nbsp;Jianping Wang ,&nbsp;Jichun Wang ,&nbsp;Dongxing Wang ,&nbsp;Jinghao Sun ,&nbsp;Degao Zhai ,&nbsp;Jiajun Liu ,&nbsp;Fangfang Zhang ,&nbsp;Zhenjiang Liu","doi":"10.1016/j.jseaes.2025.106930","DOIUrl":"10.1016/j.jseaes.2025.106930","url":null,"abstract":"<div><div>The Liushashan molybdenum deposit is located in the northern Beishan orogenic belt. The orebodies are predominantly hosted within Late Paleozoic granodiorite and quartz diorite. Two distinct mineralization types have been identified: porphyry-style mineralization and quartz-vein-style mineralization, which are characterized by stockwork-disseminated and massive quartz-vein features, respectively. Mineralization includes four paragenetic stages: (1) quartz-K-feldspar, (2) quartz-polymetallic sulfide, (3) quartz-molybdenite, and (4) quartz-calcite. Integrated fluid inclusions microthermometry and C–H–O–S stable isotope analyses were performed to constrain the properties, sources, and evolution of the ore-forming fluids, as well as the metallogenic mechanisms. Three types of fluid inclusions were identified: liquid-rich two-phase (LV-type), vapor-rich two-phase (VL-type), and pure liquid-phase (PL-type) inclusions, with LV-type constituting over 90 % of the total. Microthermometric analyses of fluid inclusions assemblages in quartz from different stages indicate homogenization temperatures of 331–431°C (Stage I), 273–367 °C (Stage II), 206–299 °C (Stage III), and 172–207 °C (Stage IV), with fluid salinities of 2.4–9.5 wt% NaCl equiv., 3.6–13.0 wt% NaCl equiv., 2.4–10.0 wt% NaCl equiv., and 2.4–7.6 wt% NaCl equiv., respectively. Combined C–H–O–S stable isotope data suggest that the ore-forming fluids were derived from deep-seated magmatic-hydrothermal systems and progressively mixed with meteoric water in later stages. Fluid boiling and mixing are the dominant ore precipitation mechanisms. Based on geological, fluid inclusions, and isotopic features, the Liushashan deposit is classified as a subduction-related porphyry Mo deposit.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106930"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Middle segment of the Red River fault: Numerical simulation of slip rates with implications for the absence of major historical earthquakes","authors":"Jianling Cao ,&nbsp;Yaolin Shi ,&nbsp;Hui Wang ,&nbsp;Xiaoxia Liu","doi":"10.1016/j.jseaes.2025.106933","DOIUrl":"10.1016/j.jseaes.2025.106933","url":null,"abstract":"<div><div>The middle segment of the Red River fault (RRF) in southwestern China has historically lacked large earthquakes, unlike its parallel northern fault zone. To explain the reason for the absence of historical seismicity on the middle RRF, we developed a 3D viscoelastic–plastic model simulating slip partitioning between these structures, using GNSS and short-baseline geodetic constraints. The simulated horizontal velocities match observations well. Based on data fitting, the optimal mechanical parameters are determined as follows: a fault viscosity of 10¹⁹ Pa·s, and plastic yield strengths of 10 MPa and 20 MPa for the straight and Big Bend sections of the middle segment of the RRF, respectively; the corresponding dextral slip rates are: 1.5 mm/a for the straight RRF section, 1.0–1.5 mm/a for its Big Bend section, 1.0–1.5 mm/a for the Chuxiong fault, 2.5–3.0 mm/a for the Qujiang fault, and 0.5 mm/a for the Shiping fault. Slip rates are more sensitive to plastic yield strength than viscosity, as simulations exceed viscoelastic relaxation time. Estimated recurrence intervals with slip rates we obtain for <em>M</em> 7–8 earthquakes on the middle segment of the RRF range from 1200 to 3500 years. This long recurrence interval—compared to local earthquake written history about four to five centuries in the region—may explain the absence of large historical earthquakes on the middle segment of the RRF. Another possible reason is that the middle RRF may currently be in a seismically quiescent period if its parallel strike-slip faults alternate in activity.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106933"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Silurian arc-continent collision and Permian-Triassic closure of Paleo-Asian Ocean in southeastern Central Asian Orogenic Belt: insight from the multiphase deformation from the eastern Bainaimiao arc belt, China","authors":"Falak Sheir ,&nbsp;Jiafu Chen ,&nbsp;Yichang Liu ,&nbsp;Xu Ma ,&nbsp;Wei Li ,&nbsp;Yuqi Liu ,&nbsp;Yi Zhang ,&nbsp;Zhenghe Zhao","doi":"10.1016/j.jseaes.2025.106918","DOIUrl":"10.1016/j.jseaes.2025.106918","url":null,"abstract":"<div><div>The collision between the Bainaimiao arc belt and the North China Craton, and the subsequent closure of the Paleo-Asian Ocean, are two major tectonic events for the Central Asian Orogenic Belt. However, the timing of these events remains controversial because the deformation fabrics that record crucial information about the collision history are poorly constrained. To address this, we conducted detailed structural analysis, quartz c-axis fabric analysis, and zircon U-Pb geochronology of the ductile deformation fabrics within the Chenjiatun shear zone, located east of the Bainaimiao arc belt. The structural analysis indicates that the deformation zone records two main ductile deformation events, D1 and D2, defined by S1 and S2 foliations. The S1 foliations (D1) trend ESE, plunge SE, and the S2 foliations (D2) trend ENE &amp; NE, plunge NW &amp; SE, respectively. Each deformation event is further subdivided into early-late sub-stages based on differences in fabric orientation and deformation characteristics. The D1a and D2 display dextral strike-slip shearing, while D1b involves sinistral strike-slip shearing. Microstructures and quartz c-axis patterns indicate that D1 occurred at high-temperature conditions (∼600–700 °C) under amphibolite facies conditions and D2 at medium temperature (∼400–500 °C) under upper green-schist facies conditions. The zircon U–Pb dating reveals that the deformation occurred at 423 <!--> <!-->Ma for D1b, 264–261 Ma for D2a, and 260–243 Ma for D2b. These results, combined with previous data, conclude that the D1 event records the Late Silurian Bainaimiao arc belt-North China Craton collision, while the D2 event represents the initial- to -final closure of the Paleo-Asian Ocean, which occurred from the Middle Permian to the Middle Triassic, followed by an intra-continental collision to the east of the Bainaimiao arc belt within the southeastern Central Asian Orogenic Belt.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106918"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 rupture process of the September 2022 Guanshan and Chishang Earthquakes: Joint inversion of seismological and geodetic data","authors":"Wei-Yu Zhang ,&nbsp;Yu-Sheng Sun ,&nbsp;Yopi Serhalawan ,&nbsp;Po-Fei Chen ,&nbsp;Ming-Che Hsieh ,&nbsp;Wu-Lung Chang","doi":"10.1016/j.jseaes.2025.106940","DOIUrl":"10.1016/j.jseaes.2025.106940","url":null,"abstract":"<div><div>On 17–18 September 2022, the Mw 6.5 Guanshan and Mw 7.0 Chishang earthquakes, struck the Longitudinal Valley (LV) of Taiwan, the collision boundary between the Eurasian plate and the Philippine Sea plate. Aftershock patterns show that the events occurred within 24 h, only a few kilometers apart, and that both ruptured the west-dipping Central Range Fault (CRF). To investigate their rupture behavior and interaction, we performed a joint inversion of teleseismic, strong-motion, and GNSS data. The resulting finite fault models revealed distinct rupture characteristics, with the Guanshan earthquake mainly rupturing down-dip with minor shallow southward extension, in contrast to the Chishang earthquake, which propagated northward toward the surface and produced two shallow asperities. Combining these models with static Coulomb stress calculations and rupture-velocity analysis indicates that Guanshan may have promoted failure of the Chishang segment through static stress transfer, and that a low-velocity zone and clustered aftershocks between the two hypocenters are consistent with a barrier that limited the northward extent of the Guanshan rupture.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106940"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precambrian crustal evolution of the southern margin of the North China Craton: Evidence from the Paleo–Mesoproterozoic sedimentary rock","authors":"Shuo Wang ,&nbsp;De-Bin Yang ,&nbsp;Xiang-Yu Yan ,&nbsp;Ke Wu ,&nbsp;Jian-Ning Liu ,&nbsp;Rui-Qing Xue","doi":"10.1016/j.jseaes.2025.106943","DOIUrl":"10.1016/j.jseaes.2025.106943","url":null,"abstract":"<div><div>Clastic sedimentary rocks offer crucial insights for deciphering the Precambrian crustal evolution. Paleo–Mesoproterozoic sedimentation is widely developed in the southern margin of the North China Craton (SNCC). Previous research has primarily concentrated on magmatism, while the information of Precambrian crustal evolution revealed by sedimentary rocks was less concerned. Hence, we present the zircon U–Pb ages, zircon Hf isotopes and whole-rock geochemical data of the quartz sandstones from the Beidajian Formation of the Ruyang Group, the Sanjiaotang Formation of the Luoyu Group and the Ma’anshan and Luotuopan formations of the Wufoshan Group within the SNCC. The detrital zircon dating, Hf isotope data and geochemical features of these formations indicate that their sediments were primarily sourced from the Neoarchean–Paleoproterozoic rock units in the SNCC, with the characteristics of mature crustal materials. Their detrital zircon age spectra and depositional environment combined with geological evidence indicate that the SNCC was in an extensional environment during the late Paleoproterozoic to early Mesoproterozoic. The Hf isotope data combined with geological evidence suggest that the crustal growth was dominant in the SNCC during the early Neoarchean (2.80–2.70 Ga), and the crustal reworking played a dominant role during the mid- to late Paleoproterozoic (2.00–1.72 Ga), while the crustal growth and reworking coexisted during the late Neoarchean (<em>ca.</em> 2.50 Ga) and early to mid-Paleoproterozoic (2.46–2.02 Ga).</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106943"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 Devonian alkaline volcanism in the North Qaidam, NW China: Insights into the Proto- to Paleo-Tethys tectonic transition","authors":"Mao Wang ,&nbsp;Xianzhi Pei ,&nbsp;Lei Pei ,&nbsp;Zuochen Li ,&nbsp;Chengjun Liu ,&nbsp;Lili Xu ,&nbsp;Ruibao Li ,&nbsp;Li Qin ,&nbsp;Xiao Wang ,&nbsp;Nan Hu ,&nbsp;Hao Lin","doi":"10.1016/j.jseaes.2025.106946","DOIUrl":"10.1016/j.jseaes.2025.106946","url":null,"abstract":"<div><div>The North Qaidam (NQ) preserves records of Paleozoic to Early Mesozoic magmatic activity and metamorphism, reflecting a complex multi-stage tectonic evolution. The Maoniushan Formation is a key stratigraphic record of the Proto- to Paleo-Tethys transition. We present petrological, zircon U-Pb geochronological, whole-rock geochemical, and Lu-Hf isotopic data for Maoniushan Formation alkaline volcanics in the Xiatuoaer area. The suite comprises basalt, basaltic andesite, and trachyte. Zircon U-Pb geochronology indicates an Early Devonian eruption age (ca. 403 – 400 Ma). Geochemically, the suite is shoshonitic, enriched in LREEs, and depleted in HREEs and HFSEs (e.g., Nb, Ta, P, Ti). Their ε_Hf(t) values range from −11.4 to + 6.8, predominantly negative (−11.4 to −3.4), indicating a mixed mantle source dominated by enriched mantle. Petrographic and geochemical data indicate the basalts originated from low-degree partial melting of a mixed, fluid-metasomatized lithosphere mantle with a minor asthenosphere component. The trachytes resulted from mixing of mantle-derived mafic magmas and crustal-derived felsic melts. Integrated regional geological<!--> <!-->data indicate<!--> <!-->the NQ subcontinental mantle was metasomatized by slab-derived fluids during Proto-Tethys oceanic subduction. During the Early Devonian, lithosphere delamination and remote response to back-arc extension in the Paleo-Tethys main ocean (Qiangtang area) triggered partial melting of this metasomatized mantle, generating the Maoniushan Formation alkaline volcanics. This magmatic event marks the onset of extensional collapse of the southern Proto-Tethys orogenic belt in the NQ, indicating the terminal stage of its tectonic cycle. Concurrent development of a local aulacogen (initial rift) along the northern NQ indicates the initial transition into the Paleo-Tethys domain.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106946"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenesis of Himalayan NYF-type granitic pegmatites: Constraints from accessory minerals in the beryl-bearing pegmatite, Kangmar Dome, China","authors":"Qiaoli Wang ,&nbsp;Lei Xie ,&nbsp;Rucheng Wang ,&nbsp;Zhichao Liu","doi":"10.1016/j.jseaes.2025.106926","DOIUrl":"10.1016/j.jseaes.2025.106926","url":null,"abstract":"<div><div>The Kangmar Dome is located in the eastern Tethyan-Himalayan leucogranite belt. A distinctive feature of this dome is the absence of leucogranite outcrops, but numerous beryl-bearing granitic pegmatite veins (hereafter referred to as beryl pegmatite) intrude the granitic gneiss host rocks. Distinct from the LCT-type pegmatite found in Himalaya, the Kangmar beryl pegmatites (pegmatite I) contain large numbers of Nb-Y-Ti oxide minerals and fluorite, which are the typical minerals of NYF-type pegmatite. Whereas, pegmatite II is characterized by abundant beryl (16 vol%) and Ta-enriched oxide minerals. Hafnian zircon (0.1 &lt; Hf^#&lt;0.5) are commonly present in pegmatite I whereas hafnon (Hf^#&gt;0.5) is only found in pegmatite II, indicating extreme fractional crystallization and intense hydrothermal fluid activity of pegmatite II. The beryl pegmatites yielded zircon ²⁰⁶Pb/²³⁸U ages, monazite ²⁰⁸Pb/²³²Th ages and muscovite Rb-Sr isochron ages of 26–25 Ma. Zircons within beryl pegmatites generally exhibit Paleozoic cores (∼499 Ma), consistent with the age of the host granitic gneisses. However, ε_Nd(t) values of the beryl pegmatites have a wider range (−16.8 to −7.7) as compared with the narrow range (−12.1 to −10.6) for the granitic gneisses. Consequently, we suggest that the Kangmar NYF-type pegmatites are genetically related to A-type granites that are possibly hidden at depth in a post-orogenic extensional setting. The granite was likely derived from Higher Himalayan Crystallines, with additional contribution from an undefined source that characterized by depleted isotopic signature. The melts experienced contamination by the host granitic gneiss during the emplacement. Our results highlight the unique type of rare-metal pegmatites of the Tethyan Himalaya.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106926"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Miocene high-pressure metamorphism of garnet-bearing amphibolites in the Cona area, southern Tibet: Insights into the tectonic evolution of the Higher Himalaya","authors":"Khizar Hayat ,&nbsp;Laixi Tong ,&nbsp;Zhao Liu ,&nbsp;Christopher J.L. Wilson ,&nbsp;Xiaohan Liu ,&nbsp;Kexin Wu ,&nbsp;Xinyue Han","doi":"10.1016/j.jseaes.2025.106935","DOIUrl":"10.1016/j.jseaes.2025.106935","url":null,"abstract":"<div><div>The metamorphic evolution of the Higher Himalayan rocks in southern Tibet has been characterized through detailed studies of metapelites, whereas the associated amphibolites remain largely unexplored. In this paper, we describe detailed petrography, mineral chemistry, phase-equilibrium modeling, and zircon U-Pb ages of garnet-bearing amphibolites in the Cona area, southern Tibet. The rocks record three distinct metamorphic stages M1, M2, and M3. Prograde stage (M1) is defined by a mineral assemblage of garnet with amphibole, biotite, and plagioclase, crystallized under pressure–temperature (P-T) conditions of 9.5 kbar and 720 °C. Peak metamorphic stage (M2) is characterized by the existence of garnet, amphibole, biotite, plagioclase, quartz, ilmenite, and rutile, with P-T conditions of 12 kbar and 810 °C. Retrograde stage (M3) comprising garnet, K-feldspar, plagioclase, and quartz, stable at 8.5 kbar and 710 °C. U-Pb ages of zircon indicate that these amphibolites experienced anatectic metamorphism between 28 and 15 Ma. There is an increase in the metamorphic thermobaric ratios from 675–835 °C/GPa to 875 °C/GPa, rising the geothermal gradients from 18.2 °C/km to 24.8 °C/km. Integrating our results with previous studies, it is concluded that the Cona amphibolites underwent peak HP metamorphism, followed by a decompressional path similar to that of Cona metapelites during the Miocene, reflecting a phase of post-collisional rapid exhumation.</div></div>","PeriodicalId":50253,"journal":{"name":"Journal of Asian Earth Sciences","volume":"298 ","pages":"Article 106935"},"PeriodicalIF":2.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}