Sandstone-hosted Zn–Pb deposits constitute a globally important zinc and lead resource. However, the difficulty in constraining the time of mineralization poses substantial challenges for researchers attempting to decipher Zn–Pb mineralization processes through diverse geological phenomena. The Yanjiao deposit, where sulfides occur as vein-like structures within bleached Jurassic-Cretaceous red beds, is temporally associated with solid bitumen and multistage calcite veinlets. This geological assemblage provides an intriguing case for studying metallogenic processes in sandstone-hosted Zn–Pb systems. Solid bitumen developed parallel to bedding planes in calcareous sandstones indicates that hydrocarbon charging might have initiated as early as during the sedimentation. X-ray fluorescence element mapping of bleached zones reveals that high-permeability hydraulic activity dominated by sandstone liquefaction serves as the primary driver for element migration within sandstones. Symmetrical bleached bands along fractures margins were filled with solid bitumen + pyrite/marcasite (S2) + hydrothermal calcite. Fracture-hosted solid bitumen constitutes post-diagenetic thermal cracking or oxidation products derived from hydrocarbon fluid migration processes. The δ34SVCDT values of these S2 iron sulfides range from − 12.36‰ to + 36.12‰. Negative δ34SVCDT values indicate that H2S derived from organic compounds thermal cracking played a significant role in the initial stages of thermochemical sulfate reduction (TSR) within low-temperature open-system environments. Subsequent δ34SVCDT values ranging from moderately negative to positive values document mixing between thermal cracking-derived H2S and late-stage TSR-generated H2S characterized by progressive 34S enrichment. During Zn–Pb mineralization stage (S3), S3 sphalerite exhibits progressive enrichment in heavier sulfur isotopes from early to late sub-stages (S3-sp1: -25‰ to -14‰ and S3-sp3: -13.5‰ to -2.61‰), indicating that within the closed system, concurrent the reactions between hydrocarbons and sulfate facilitated the generation of increased quantities of H2S with elevated δ34SVCDT values. Rare earth element geochemistry of calcite reveals as shift from highly reducing (pre-ore: negative Eu anomaly) to moderately reducing (post-ore: positive Eu anomaly) hydrothermal conditions during hydrocarbon-aided reduction of sulfate. Uranium–lead dating of multi-stage fracture-filling calcites constraints mineralization to 39–28 Ma (Late Eocene–Oligocene), coinciding with late-stage Himalayan-Tibetan lateral collision orogeny-driven fluid pulsing. We develop a summary model for sandstone-hosted Zn–Pb deposits that provides a framework for future exploration in tectonically active orogenic belts.

When and how the Cimmerian micro-continental blocks break away from the Eastern Gondwana continent is one of the outstanding questions that is closely related to the pattern of opening of the Neo-Tethyan ocean. This ocean is considered to have opened at similar to 280-270 Ma, triggering extension and the formation of Cimmerian micro-continental blocks. How these micro-continental blocks responded to following extension during their northward drift is another issue in the paleogeographic reconstruction of the Lhasa terrane, one of prominent Cimmerian micro-continental blocks. Documentation geochemical nature of magmatic processes occurred between the opening (similar to 280-270 Ma) and the initial subduction (similar to 230-220 Ma)of the Neo-Tethyan oceanic lithosphere could provide important constraints on the issues posed above. The Taizhao granitic intrusion in the eastern Lhasa terrane consists of coarse-grained and fine-grained granites, which yield zircon U-Pb age of 267 Ma and 259 Ma, respectively. Elemental and isotopic data suggest that their parental magmas have experienced various degrees of fractional crystallization of plagioclase and iron-oxides during their magmatic differentiation. However, the coarse-grained granites represent the more primitive melts and show geochemical characteristics (high K2O + Na2O-CaO (6.62-8.52 wt%), 10000*Ga/Al (generally >2.6), low Y/Nb (0.73-0.98) ratios, T-Zr = 750 degrees C-801 degrees C) of A1-type granite. The coarse-grained granites mainly derived from melting of middle to lower crustal rocks (Sr-87/Sr-86(t) = 0.705670 to 0.703829, epsilon(Nd)(t) = -5.5 to -5.1, epsilon(Hf)(t) = -2.6 to -8.5) with some mantle input under high temperature, injected with some mantle-derived magmas pulse associated at continental rift settings. With temperature decrease gradually (T-Zr = 665 degrees C-672 degrees C), felsic magma evolved further forming fine-grained granites with slightly low radiogenic Sr-87/Sr-86(t) varying from 0.705670 to 0.703829 and similar Nd-Hf isotope composition (epsilon(Nd)(t) = -5.7 to -5.5, epsilon(Hf)(t) = -2.2 to -10.6). The Lhasa terrane separated from the northern margin of Eastern Gondwana continent no earlier than the Middle Permian, then drifted away to the north and became a belated part of Cimmerian subcontinent no later than late Triassic.

Secular isotopic variations in the early Paleozoic magmatic rocks provide important constraints on the deep geodynamic processes and their shallow crustal responses. The Himalayan terrane contains an extensive record of the early Paleozoic magmatism, yet its tectonic setting, deep-earth processes, and metallogenic implications remain poorly constrained. In this study, we report two groups of granitic gneisses with protolith ages of 473-466 Ma from the northern Leo Pargil dome in the western Tethyan Himalaya. Both groups are peraluminous and belong to the calc-alkaline series with relatively high MgO (0.18-1.62 wt%) and total FeO (0.51-4.28 wt%) contents. Group A samples show W-Sn enrichments with relatively constant epsilon Nd(t) ranging from -7.7 to -6.2 (TDM 2 = 1.8-1.7 Ga), whereas group B has relatively lower and variable epsilon Nd(t) (-14.8 to -7.1) and TDM 2 of 2.4-1.8 Ga, indicating a contribution of ancient crustal material to the magma source. In combination with tectonic, sedimentary, and metamorphic records, an Early Ordovician magmatic flare-up and a concurrent negative Nd isotopic excursion have been revealed. We suggest a three-stage tectonic evolution involving Andean-type subduction, Cordilleran-type orogeny, and post orogenic extension. The flare-up occurred during the Cordilleran-type orogenic phase, driven by back-thrusting-induced partial melting of the Lower Himalayan Sequence and subducted Indian continental crust, which also explains the isotopic shift. Furthermore, this work highlights the W-Sn mineralization potential of early Paleozoic Himalayan granitoids along the Himalayan orogenic belt.

Eocene granite in the Northern Himalayan Gneiss Domes (NHGD), Southern Tibet, offers insights into the early India-Asia collision, yet the source anatectic pressure remains controversial. This study employs zircon U-Pb geochronology, whole-rock geochemistry, and Sr-Nd isotopes on a Late-Eocene granites-intermediate rocks suite from the Yardoi gneiss dome, combined with phase equilibrium calculations on metabasites to unravel their petrogenesis and implications. Zircon U-Pb dating indicates that these rocks crystallized at ca. 43-40 Ma. The granites exhibit high Sr/Y ratios (44-111), are peraluminous and Na-rich. The intermediate rocks have higher Al2O3, CaO, and Na2O than the granites, while other elements remain comparable. Sr-Nd isotopes indicate that metabasite is the primary source for both rock types. Phase equilibrium calculations imply that the granites originated from high-pressure melting of amphibolite at 750-800 degrees C and 1.3-1.8 GPa, yielding a plagioclase-depleted residue. Variations in muscovite content in the residua may explain the differing Rb-Ba concentrations observed in the granites. Limited HREE fractionation in the granites may stem from slow element diffusion in subsolidus garnet and low peritectic garnet abundance. Moreover, the intermediate rocks likely formed under similar P-T conditions but from alkaline metasomatized metabasite. We conclude that the decrease of plagioclase, while muscovite remains stable, is a common feature during metabasite high-pressure melting. The Eocene primary high Sr/Y magmatism resulted from melting of the thickened lower crust, with high-density residues potentially accumulating and detaching due to gravitational instability, triggering extensional tectonics in the NHGD since ca. 35 Ma.

Abstract Lower crustal sulfide‐bearing Cu‐rich cumulates, mainly occurring as hornblendite, have been proposed as a critical source component for the development of giant porphyry Cu deposits (PCDs); however, their mineralogical and geochemical nature remain elusive. We present integrated geochemical and geochronological investigations on a suite of hornblendite from the Gangdese continental arc in southern Tibet. Zircon U‐Pb geochronology documents a prolonged magmatic cooling and crystallization spanning from the Late Triassic to the Early Jurassic (ca. 207∼200 Ma; ∼6 myr). The hornblendite is characterized by (a) variable SiO2, Al2O3, MgO and Fe2O3T contents, negative anomalies of Nb, Ta, Zr and Hf, high Sr/Y ratio and Cu content (up to 1,430 ppm); (b) relative oxidized conditions represented by elevated bulk Fe3+/(Fe3++Fe2+) and Ce/Ce* ratios; (c) depleted mantle‐like Sr and Nd isotopic compositions (87Sr/86Sr(t) = 0.7038 to 0.7046, εNd(t) = +5.1∼+6.4), which are consistent with those in the coeval PCDs. These results imply that these hornblendites were originated from partial melting of mantle wedge metasomatized by subduction‐derived fluids. Considering the temporal and spatial distribution of subduction‐ and collision‐related PCDs, we propose that the deep‐seated hornblendite cumulates in the lower part of the arc crust could serve as an important potential source for PCDs and have played an important role in Cu mineralization in the Gangdese arc.

The Remula region, located within the Cona Rift of the Himalayan orogenic belt, extensively exposes Miocene leucogranites. Geochemical characteristics indicate that the granites in this area show high potential for rare-metal mineralization. LA-MC-ICP-MS zircon U-Pb dating indicate that the granites crystallized at 16.86 +/- 0. 19Ma. Based on whole-rock major, trace and rare earth element compositions, the leucogranites can be classified into two types: Type A leucogranites and Type B Li-rich aplites. Type A leucogranites are characterized by: (1) high SiO2, Al2O,, K2O and Na2O, but low FeO, MgO, MnO, CaO and TiO2 contents; (2) elevated Rb but low Sr and Ba, together with high Rh/Sr ratios; (3) enrichment in LREEs and depletion in HREEs with a pronounced negative Eu anomaly; and (4) high initial (8)7Sr/Sr-86(1) ratios but low epsilon(ND) (1) values. The highly correlated variations of trace elements in Type A leucogranites suggest their formation was controlled by fractional crystallization of minerals such as plagioclase and mica from granitic melts. Compared to Type A leucogranites (Li = 64 * 10 (- 6) - 151 x 10 (-) 6) Type B Li-rich aplites (Li=141 x 10-(6) 970 * 10(-6) ) exhibit the following characteristics: (1) Relatively higher Al2O, and K2O, but lower SiO2, Na2O, FeO, MgO, CaO and TiO2 contents; (2) elevated Li, Ba, Rb, Sr contents and K/Rb ratios, but lower Rb/Sr ratios; (3) relative depletion in LREE with slight enrichment in HREE, and a weak negative Eu anomaly; and (4) markedly lower initial Sr/Sr(1) ratios but higher epsilon(ND) ((t)) values. The elemental and isotopic characteristics of Type B Li-rich aplites, combined with foamy textures in zireon cathodoluminescence images, indicate substantial metasomatic modification by K-rich hydrothermal fluids. Based on the geochemical features of Type B Li-rich aplites and published data from the Cuona area, it can be inferred that potassium-rich hydrothermal fluids derived from deep sources metasomatized the Miocene granites within the rift tectonic setting, leading to the formation of Li-rich aplites. This genetic model provides a new perspective for understanding rare-metal mineralization processes in the Himalayan orogenic belt.

The upper-crustal extensional structures developed in the Himalayan orogen record deep dynamics, that have played significant roles in the Himalayan tectonic evolution. This study presents new detailed field investigations, microstructures, quartz [c] axis crystallographic preferred orientation (CPO) patterns, kinematic vorticity, deformation temperatures, zircon U-Pb, and mica Ar-40/Ar-39 geochronology data of the two sets of intersecting extensional structures in the Cona area of the eastern Himalayan orogen. The results suggest that the Cona Detachment (CD) is mainly in simple shear deformation and the ductile deformation temperature ranges from 280 degrees C to 517 degrees C. It was active between 19 and 16 Ma, and ceased at 15 Ma. However, the Cona Rift (CR) is mainly in pure shear deformation and its top-down-to-the-E ductile deformation is recorded at temperatures from 500 degrees C to 608 degrees C. It initiated at similar to 16 Ma, and ceased activity before 10 Ma. During the transition from N-S to E-W extension, the change in dynamic mechanism led to coupled fluid injection and crustal heating. This study indicates that the N-S and E-W extensional structures in the Cona area exhibited overlapping deformation histories during 16-15 Ma.

In the Himalayan orogenic belt, numerous Cenozoic granites are enriched in rare metals, and three giant rare metal deposits have been discovered. However, the mechanisms responsible for rare metal enrichment and mineralization remain poorly understood. In the Nyalam area, a suite of granites intruding the Southern Tibet Detachment System have high rare metal contents (100-284 ppm Be, 24-117 ppm Nb, 15-102 ppm Ta). Zircon UPb analyses revealed that these granites formed ca. 17.3 Ma. Compared with barren granites in nearby areas, the rare metal-rich granites are characterized by (1) higher Na2O and MnO contents and lower TiO2 and MgO contents; (2) higher Rb and Rb/Sr values but lower Sr and Ba contents; (3) lower REE contents, nearly flat REE patterns and pronounced negative Eu anomalies; (4) higher Be, Nb, Ta, Rb, Cs, Ga, and Tl contents but lower B contents; and (5) lower Sr-87/Sr-86(t) and epsilon(Nd)(t) values. Significantly, when Nb/Ta < 5 and Zr/Hf < 20, melt structures undergo changes characterized by increasing M/F ratios (network formers/modifiers). These geochemical compositional variations between the two types of granites imply the combined effects of fractional crystallization and hydrothermal alteration but ultimately derived from melt structural changes. Depolymerization reduces melt viscosity and increases NbTa solubility, thereby enhancing the efficiency of fractional crystallization and facilitating rare metal enrichment.

Syn-magmatic garnet-bearing and garnet-free leucogranites from the Tethyan Himalaya display pronounced differences in major element, trace element, and Sr-Nd isotope geochemistry, reflecting a complex magmatic evolution process. Compared with biotite-bearing leucogranites, the garnet-bearing leucogranites have (1) relatively higher SiO2, FeO*, and MnO contents; lower Al2O3, CaO, P2O5, and TiO2 contents; and lower A/CNK values; (2) higher Y, Yb, Zr, Hf, and Th contents and lower Ba and Sr contents; (3) notably higher heavy rare earth element contents and more pronounced negative Eu anomalies; and (4) significantly higher 87Sr/86Sr(t) ratios and epsilon Nd(t) ratios. Furthermore, the garnets in the garnet-bearing leucogranites exhibit characteristics typical of magmatic origins. On the basis of field observations and geochemical data, we propose the following model: during migration and intrusion, high-temperature granitic magma that ultimately formed the biotitebearing leucogranites, incorporated wall rocks, thereby releasing both material and ancient garnet crystals from the wall rocks into the magma. The assimilation of the wall rocks elevated the FeO*, MnO, and HREE contents and Sr-Nd isotopic compositions and ultimately promoted the crystallization of magmatic garnets and the formation of garnet-bearing leucogranites in the Kongbugang area. These observations provide new constraints on the mechanism responsible for the development of geochemical heterogeneities in granites and the mechanism responsible for the formation of magmatic garnets in S-type granites and highly fractionated I-type granites.

The various extensional structures developed at the shallow surface are the coupled embodiment of the deep dynamics, which have played significant roles in the Himalayan tectonic evolution. The two sets of intersecting extensional structures in the Cona area of eastern Himalayan orogen are studied, this paper presents new detailed field investigations, microstructures, quartz [c] axis CPO patterns, kinematic vorticity, deformation temperatures, zircon U-Pb, and mica 40Ar/39Ar geochronology. The results suggest that the Cona Detachment (CD) is mainly in pure shear deformation and the ductile deformation temperature ranges from 280 to 517℃. It was active between 19 and 16 Ma, and ceased at 15 Ma. However, the Cona Rift (CR) is mainly in simple shear deformation and its top-down-to-the-E ductile deformation is recorded at temperatures from 500 to 608℃. It initiated at ~16 Ma, and moved until 10 Ma. Statistically, it was found that the cessation of STDS and the initiation of NSTR seem to follow a youthful trend from west to east along the Himalayan orogen, and there is an overlap in the period of activity between them. Combined with previous studies, we speculate that this process resulted from the Indian plate tearing and the asthenosphere upwelling. Ultimately, this tectonic event leads to the mid-Miocene regime transition. The shallow surface reflects the change from N-S to E-W extensional movement in the mid-Miocene, while the fluid content, heat source, and stress field conditions are also changed in response.

The Dingri-Tangra Yumco rift is an important component of the Southern Tibet Rift System (STRS), where exposed syenite porphyry serve as a key petrological probe for understanding the Miocene magmatic-tectonic evolution of the southern Tibetan. The syenite porphyry occurs as dike, and composed of K-feldspar and biotite, which formed at similar to 12.5Ma, exhibits relatively high contents of SiO2 (58.79%similar to 61.16%), K2O (8.52%similar to 8.86%), and Al2O3 (13.72%similar to 14.06%). They are enriched in light rare earth elements (LREE) and depleted in heavy rare earth elements (HREE). They show enrichment in large-ion lithophile elements (LILEs) such as Th, K, Rb, and Ba but depletion in high-field-strength elements (HFSEs) like Nb, Ta, and Ti. They exhibit initial Sr-87/Sr-86(t) ratios of 0.717757 similar to 0.718018, with epsilon(Nd)(t) values of -13.0 similar to-12.5, and relatively homogeneous and elevated Pb isotopic ratios (Pb-206/Pb-204(t)=18.46 similar to 18.47, Pb-207/Pb-204(t)=15.75, and Pb-208/Pb-204(t)=39.44 similar to 39.46). Clinopyroxene compositions imply fractional crystallization of olivine and clinopyroxene during magmatic evolution. These geochemical features suggest that the syenite porphyry originated from partial melting of a fluid-metasomatized, enriched sub-continental lithospheric mantle (SCLM) and subsequently experienced minor crustal contamination during their ascent and emplacement. The geochemical differences between the syenite porphyry and coeval high-K rocks in this region, such as the Tangra Yumco ultrapotassic rocks, the Dagze Co high Sr/Y rocks, and the Zhunuo porphyry, reflect the Miocene magmatic evolutionary sequence of high-K to potassic-ultrapotassic magmas in the southern Tibetan Plateau. During the post-collisional stage (26 similar to 10Ma) following the India-Asia continental collision, the subducted Indian lithospheric slab underwent rollback and break-off, leading to asthenospheric mantle upwelling and melting of the metasomatized mantle. This process triggered the transition from compression to extension in the Lhasa terrane, forming the Dingri-Tangra Yumco rift. The syenite porphyry in this study and other high-K rocks in this region represent the magmatic response to this tectonic event.

Cenozoic leucogranites in the Himalayan orogenic belt represent the product of crustal analexis followed by various degrees of magma differentiation during the continental collisional orogeny. They provide a key litho-probe to unravel the tectonic-metamorphic-magmatic processes responsible for the construction of continental orogens. This paper focuses on the rutile- and andalusite-bearing leucogranites occurred in the Nyalam area of southern Tibet. Through detailed petrographie observations, zircon U-Pb geochronology, mineral trace element geochemistry, and whole-rock geochemical analysis, we constrain the genetic types of andalusite and rutile in these rocks and further discuss their physio-chemical formation conditions and regional tectonic dynamic setting. The results indicate that the Nyalam granite formed in the Early Miocene (ca. 17.5Ma and show high temperature (similar to 745 degrees C ) and. strongly peraluminous characteristics. Petrographic analysis reveals that the granular rutile in the leucogranite is of magmatic origin, crystallized directly from the magma, whereas the acicular rutile in the granite is a product of hydrothermal alteration of biotite. Euhedral andalusites in these leucogranites show prominent compositional zoning and well-developed reaction texture and suggest that they are of magmatic origin and crystallized at relatively high temperature conditions, These features observed in these Miocene leucogranites suggest that the Nyalam region was under an E-W extensional tectonic setting in the Early Miocene, possibly resulted from asthenospheric upwelling and heating. Such a process provided the crucial heat source for deep crustal partial melting and the crystallization of magmatic andalusite and rutile.

The geochemistry of granite is largely controlled by physical and chemical parameters that are closely linked to tectonic processes in evolving orogenic belts. Therefore, temporal changes in the geochemical compositions of granites could be used to infer critical shifts in tectonic processes. The Himalayan leucogranites are crustal anatexis products, providing a case to formulate petrogenetic models for granites and test tectonic models. From west to east, in the High Himalaya and the Tethyan Himalaya, two groups of leucogranites are derived from fluid-absent melting (Group A) and fluid-fluxed melting of muscovite (Group B), respectively. In the Cona and Mount Everest areas, Group B granites crystallized at 26−10 Ma, and Group A granites formed at 19−13 Ma. Group B granites have higher CaO, Sr, Ba, Zr, Hf, Th, Sr/Y, Zr/Hf, and Th/U, and lower Rb, Nb, Ta, U, Rb/Sr, and 87Sr/86Sr than those in Group A granites. These geochemical differences highlight the role of deep-origin fluids and the dissolution control of the accessory phases on the geochemical compositions in silicic magma systems. Field and microstructural observations show that E-W extension occurred synchronously with the granite intrusion derived from fluid-fluxed melting. Elevated heat flow accompanying the E-W extension could dehydrate hydrous minerals and release fluids from deep-seated crust (e.g., Lesser Himalayan Sequence). Such fluids could flux and melt the metasedimentary rocks within the High Himalaya and produce Group B granites. Together with literature data, from the Lhasa terrane to the Himalayan belt, E-W extensions in Tibet may have initiated as early as 26 Ma.

The Himalayan Cenozoic leucogranites record important information on the geochemical and tectonic physical effects of crustal partial melting and granite emplacement. Compared with the Eocene granites formed under thickened crustal conditions and Miocene granites formed during extensional process, the Oligocene granites are relatively distributed in a limited area, and there is still controversy about their sources and formation mechanisms. The Nyalam region is located in the central part of the Himalayan orogenic belt, where the 32. 1Ma tourmaline-biotite-bearing granite, the 29. 8Ma biotite-bearing granite, and the 26. 6Ma tourmaline-biotitebearing pegmatitic granite intruded into the upper part of the High Himalayan Crystalline Sequence. The three groups of Oligocene granites have the following characteristics: ( 1) high SiO2, Al2O3, K2O and Na2O contents, with A/CNK > 1. 0; ( 2) negative anomalies of Ba, Nb, Ta, Sr and Ti; (3) slightly enriched in light rare earths, depleted in heavy rare earths, highly variable Eu anomalies and weak negative Nd anomalies; (4) uniform initial Sr and Nd isotope ratio, with (87) Sr/ (86) Sr( t) =0. 7463 similar to 0. 7471 and eNd (t) = 15.0 similar to -14. 6. Furthermore, the tourmaline-biotite-bearing granites and pegmatitic granites have higher Sr and Ba and lower Rb/Sr ratios than the other one, and their Rb/Sr ratios are not correlated with Ba and Sr contents, which suggest that they are products of B -rich fluid -present partial melting of metamorphic sedimentary rocks. While the biotite-bearing granites have lower Sr and Ba contents and higher Rb/Sr ratios, and Rb/Sr ratio negatively correlated with Ba and Sr contents, which suggest that they are products of fluid -absent melting of metamorphic sedimentary rocks. Combined with the published research results in the Himalayan orogenic belt, it is concluded that the source of the Oligocene granites is transformed from lower crustal basic material to middle crustal metamorphic sedimentary rocks, demonstrating the process of upward migration of the source, in addition, the Oligocene granites undergo an important period of magmatic hydrothermal metasomatism. The Oligocene partial melting recorded the response of the deep crust during the transition stage from thickening to extensional collapse in the Himalayan orogenic belt and promoted the exhumation of the High Himalayan Crystalline Sequence.

Laser ablation sector field inductively coupled plasma-mass spectrometry(LA-SF-ICP-MS)is widely applied in U-Pb dating of zircon due to its remarkable sensitivity.However,the utilization of a magnetic sector mass analyzer imposes constraints on its scanning speeds,potentially affecting the concurrent acquisition of U-Pb isotopes and other trace elements.Here a method for simultaneous zircon U-Pb dating and key trace elements quantifying by LA-SF-ICP-MS were developed.Seven zircon U-Pb standard samples were measured to assess the method's feasibility.Experimental data indicate that simultaneous collection of U-Pb isotopes and other trace elements may decrease signal stability,particularly for low-content isotopes like 207Pb,which in turn leads to an increased age uncertainty and dispersion for single analyses.However,the accuracy of the concordance age and weighted mean 206Pb/238U age of each sample,and the statistical results of all data points,are not affected significantly.Compared to TIMS ages,the discordance in these ages across all samples remains below 1.0%and 0.7%,respectively,meeting the requirements of U-Pb geological dating.Furthermore,the determination of key trace elements in zircon samples shows relative errors to recommended values of less than 10%.LA-SF-ICP-MS can accurately determine both zircon U-Pb ages and trace element contents simultaneously.The BRIEF REPORT is available for this paper at .

Two suites of mafic dykes, T1193 -A and T1194 -A, outcrop in Gyangze area, southeast Tibet. They are in the area of Comei LIP and have indistinguishable field occurrences with two other dykes in Gyangze, T0902 dyke with 137.7 +/- 1.3 Ma zircon age and T0907 dyke with 142 +/- 1.4 Ma zircon age reported by Wang YY et al. (2016), indicating coeval formation time. Taking all the four diabase dykes into consideration, two different types, OIB-type and weak enriched -type, can be summarized. The "OIB-type" samples, including T1193 -A and T0907 dykes, show OIB-like geochemical features and have initial Sr-Nd isotopic values similar with most mafic products in Comei Large Igneous Provinces (LIP), suggesting that they represent melts directly generated from the Kerguelen mantle plume. The "weak enriched -type " samples, including T1194 -A and T0902 dykes, have REEs and trace element patterns showing withinplate affinity but have obvious Nb-Ta-Ti negative anomalies. They show uniform lower epsilon Nd(t) values (-6--2) and higher 87Sr/86Sr(t) values (0.706-0.709) independent of their MgO variation, indicating one enriched mantle source. Considering their closely spatial and temporal relationship with the widespread Comei LIP magmatic products in Tethyan Himalaya, these "weak enriched -type" samples are consistent with mixing of melts from mantle plume and the above ancient Tethyan Himalaya subcontinental lithospheric mantle (SCLM) in different proportions. These weak enriched mafic rocks in Comei LIP form one special rock group and most likely suggest large scale hot mantle plume -continental lithosphere interaction. This process may lead to strong modification of the Tethyan Himalaya lithosphere in the Early Cretaceous. (c) 2024 China Geology Editorial Office.

The Réunion mantle plume is known to have produced the Deccan Traps in west-central India, but its early evolution before the Deccan eruption remains poorly constrained. In this paper, we report a mafic intrusion in the eastern Tethyan Himalaya, the Manla dolerite sill, with a U–Pb zircon age of 68.7 ± 1.0 Ma and Réunion plume-like geochemical features. Similar to other ∼73–68 Ma pre-Deccan rocks scattered across the northern Indian plate, the Manla dolerite likely represents initial melts from the Réunion plume. Considering the widespread Campanian stratigraphic hiatus throughout the Tethyan Himalaya, we propose that these pre-Deccan geological records in the Himalaya area resulted from the Réunion plume evolution process involving upwelling, ponding and rapid spreading along the base of the northern Indian plate during 80–70 Ma. Major and trace element modeling results show that the Manla rocks, like the largest Western Ghats sequence in the Deccan area, have low melting pressure, suggesting that they formed in preexisting thin areas. Combined with lithosphere thickness variations in the Indian plate, the thick northern Indian plate may have been the key factor inhibiting massive melt production when the Réunion plume head first impinged on it, and the large Deccan eruption was triggered when the thin central-western Indian plate moved over the Réunion plume. The early arrival of the Réunion plume head coincides with the unusual acceleration of the Indian plate starting at ∼75–70 Ma and suggests a prolonged plume - Indian plate interaction period. Our reconstructions suggest that plume heads can impact several million years ahead of large igneous provinces formation and can affect the movements of the overlying plate in an incubation way.

Since separating from the Eastern Gondwana supercontinent in the Late Jurassic, the Indian plate drifted northward long- distance until it collided with the southern margin of Asia. The tectonic evolution of the Indian plate and its dynamic mechanisms during this long drift are still debated. In this paper, we report two diabase plutons located in the middle and the cast parts of the Tethyan Himalaya, the northernmost part of the Indian plate. They both have zircon U-Pb ages of 95 Ma, suggesting one Late Cretaceous extension event in the northern margin of the Indian plate. They belong to the tholeiite series with intraplate affinity, but their contrasting geochemical features from cast to central indicate different mantle sources. In the cast, the Dalong diabases have high Ti content (TiO2, >3.5%) and OIB-like trace element characteristics, similar suggests that they are formed by partial melting of asthenosphere material without crustal contamination. In the central, mafic rocks in the Lhagoi Kangri area have low Ti content (TiO22 <2.0%) and MORB-like REE features, and the characteristics of trace elements indicate that their arca is the enriched lithospheric mantle. The primary magma compositions recovered by the PRIMACALLC2 software show that source melting depth of the castern samples is shallower than that of the central samples. We propose that during the rifting process in the northern margin of the Indian plate at 95Ma, the extension of the thin cast lithosphere caused partial melting of asthenosphere material; while in the central, the melting of asthenosphere material was prevented due to the thick lithosphere. Thus, the upwelling asthenosphere heated the bottom of the lithosphere and caused the melting of the overlying enriched lithosphere mantle materials during this continental rifting process. Considering the Late Cretaceous magmatic peak in the Gangdese are belt, the ca. 95 similar to 90Ma mafic magmatism and continental extension in the Tethyan Himalaya should have been caused by the enhanced slab pull generated by the roll back of the subducted Neo-Tethyan slab. This passive-margin extension event was synchronous with the similar to 90Ma acceleration of the Indian plate. Different from the mantle plume push mechanism proposed by previous studies, magmatic data in this paper suggests that the slab pull force may play important role in the northward drift of the Indian plate.

A series of three CGSP‐P phosphate matrix reference materials, with variable element mass fractions, were synthesised by co‐precipitation with CaCl2 and (NH4)3PO4 to form a hydroxylapatite matrix. Each powder sample was packaged into multiple bottles and pressed into tablets as replicates. The within‐bottle homogeneity was evaluated by the repeatability of element mass fractions of six spots in per tablet of CGSP‐Ps by LA‐ICP‐MS. For the between‐bottle homogeneity evaluation, one approach adopted the % RSD of element mass fractions in twelve different tablets from twelve bottles in the same reference material in comparison with the repeatability field of LA‐ICP‐MS analyses obtained from homogeneous glasses, and the other used a one‐way analysis of variance (ANOVA) approach. Most of the elements (e.g., Mg, Ca, P, Mn and REE) were homogenous within 10% RSD, and other elements (e.g., Si, Al, K, Rb, Cs and Ni) were considered heterogeneous (with > 20% RSD). All of the elements passed the t‐test except Ni in CGSP‐P3, and V, Cr, Ni, Zr, Gd, Dy and Th in CGSP‐P4 after a 29‐month period stability examination by LA‐ICP‐MS. The preliminary reference values and standard uncertainties for CGSP‐Ps are given with a network of methods and eight laboratories by bulk analysis according to ISO Guide 35:2006 and JJF 1343‐2012.

The Kyzylkum Desert, as a transition area of different dust source in Central Asia, provides and reserves a large amount of dust transported by different atmospheric circulation systems, affecting Uzbekistan and downwind East Asia. However, there remains very few investigations about sediment sources and control factors of the desert. We hereby first present a provenance study on the Kyzylkum Desert, utilizing detrital zircon U‐Pb ages of samples composed of desert sand, alluvial sediments from Amu Darya River and piedmont of Southwest Tianshan Mountains. The results reveal that the Southwest Tianshan Mountains contribute the majority of the Kyzylkum desert sand, and the river system, dominated by Syr Darya, controls the sediment provenance of the desert. Moreover, little contribution from the Kyzylkum and Nurata segments indicates that wind erosion on the bedrocks is weak. However, the aeolian process is still crucial but deposit and storage of dust are determined by local topography.