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Oligocene and Miocene Himalayan anatexis is generally thought to have been induced by intracrustal heating or processes without the involvement of mantle-derived heat and materials, suggesting that the Himalayan leucogranites are typical examples of purely crustal melts. This study focuses on a Miocene leucogranite at Langkazi within the Himalayan orogen, an intrusion that contains a large number of dioritic enclaves. These enclaves have typical igneous textures, contain acicular apatites, and have back-veining structures, quenched margins, and crystallization ages identical to the hosting two-mica granites, indicating that these enclaves are magmatic. Although the enclaves are evolved, the most primitive samples contain high concentrations of MgO (up to 4.3 wt.%), Cr (up to 159 ppm), and Ni (up to 102 ppm), are strongly enriched in large-ion lithophile elements, are depleted in high-field-strength elements, have negative ε Nd(t) values (–8.6 to –6.1), and have relatively high 87 Sr/ 86 Sr (i) values (0.7085–0.7137), suggesting that they were derived from a relatively enriched region of the lithospheric mantle source. Whole-rock geochemical data indicate that the hosting Langkazi leucogranite formed from magmas generated by the partial melting of metapelite material within the High Himalaya crystalline sequence, and these magmas subsequently mixed with mantle-derived melts that are now represented by the Langkazi dioritic enclaves. This indicates that mantle-derived material played an important role in the generation of the Langkazi intrusions. The whole-rock geochemical compositions of samples from the study area also indicate that the primary melts that formed the Langkazi enclaves were significantly contaminated by the relatively juvenile Himalayan lower crustal material, suggesting in turn that these mantle-derived magmas underwent MASH (crustal melting, melt assimilation, magma storage, and homogenization) processes at the base of crust, introducing heat to the lower crust. This mantle-derived heat may have induced partial melting of the Himalayan lower crust, forming adakite-like magmas. Although the small volumes of these dioritic enclaves suggest that this heat may have assisted the genesis of the north Himalayan granites and the High Himalayan leucogranites, whereas in situ crustal radiogenic heating, shear heating, and decompression melting dominated the melting processes in this region. [ABSTRACT FROM AUTHOR]

Abstract: We have conducted a whole-rock geochemical, U–Pb zircon geochronological, and in situ zircon Hf–O isotopic compositional study of rocks in southern Tibet from the Langxian igneous suite (including a lamprophyre dyke, mafic enclaves, a granodiorite, and a two-mica granite) and the Nuri igneous suite (a quartz–diorite). U–Pb zircon dating indicates that the timing of crystallization of the mafic enclaves and host granodiorite of the Langxian suite are ca. 105Ma and 102Ma, respectively, that the Langxian lamprophyre dyke and the two-mica granite were emplaced at ca. 96Ma and 80–76Ma, respectively, and that the Nuri quartz–diorite was emplaced at ca. 95Ma. With the exception of the lamprophyre dyke and mafic enclaves in the Langxian area, felsic rocks from the Langxian and Nuri igneous suites all show signs of a geochemical affinity with adakite-like rocks. The high Mg-numbers, high abundance of compatible elements, high εNd(t) (2.7 and 2.8) and δ18O (8.9 and 9.2‰) values, elevated zircon εHf(t) (11.0–17.0) values, and low 87Sr/86Sr(i) ratios (0.7040), collectively indicate that the Nuri adakite-like quartz–diorite was derived from partial melting of the low temperature altered Neo-Tethyan oceanic crust, and that these dioritic magmas subsequently interacted with peridotite as they rose upwards through the overlying mantle wedge. The observation of identical differentiation trends, similar whole-rock Sr–Nd and zircon Hf isotopic compositions, and consistently low (Dy/Yb)N ratios among the Langxian igneous suite rocks, indicates that the adakite-like granodiorite was produced by low-pressure fractional crystallization of precursor magmas now represented by the (relict) mafic enclaves. However, relatively high Al2O3 contents, low MgO, Cr and Ni contents, and low (La/Yb)N and (Dy/Yb)N values indicate that the two-mica granite was derived from partial melting of the southern Tibetan mafic lower crust in the absence of garnet, while isotopic data suggest that at least 70% of the magma source region was juvenile materials. Combined with the presence of HT (high temperature) charnockitic magmatism, HT granulite facies metamorphism, and large volumes of Late Cretaceous batholiths, the oceanic-slab-derived Nuri adakitic rocks indicate a substantial high heat flux in the Gangdese batholith belt during the Late Cretaceous, which may have been related to subduction of a Neo-Tethyan mid-ocean ridge system. According to this model, hot asthenosphere would rise up through the corresponding slab window, and come into direct contact with both the oceanic slab and the base of the overlying plate. This would cause melting of both the oceanic slab and the overlying plate by the addition of heat that was ultimately linked with peak magmatism and the significant growth and chemical differentiation of juvenile crust in southern Tibet during the Late Cretaceous (105–76Ma). In addition, the petrogenesis of the Langxian adakite-like two-mica granite indicates that the southern Tibetan crust was still of normal thickness prior to the emplacement of these intrusions at ca. 76Ma. This probably means that large parts of southern Tibet were not very highly elevated prior to the Indian–Asian collision. [Copyright &y& Elsevier]

Abstract: We describe the whole-rock geochemistry, biotite Ar–Ar and zircon U–Pb geochronology, and in situ Hf–O isotopic compositions of the Linzhi two-mica granitoid in the southeastern Lhasa terrane. The granitoids are calc-alkaline to high-K calc-alkaline in composition, and they have geochemical affinities with adakites. The whole-rock geochemistry, with high SiO2 and Al2O3 contents, low MgO, Cr, and Ni contents, low Mg# values, negative εNd(t) (−6.2 to −2.9), and low 87Sr/86Sr(i) (0.7059–0.7074), together with the in situ zircon Hf–O isotopic data (εHf(t) =−2.7 to 2.7; δ18O=7.2‰–8.8‰), indicates that the granitoid was derived mainly from the partial melting of a rejuvenated lower crust underneath the Lhasa terrane. This lower crust was dominated by ancient crustal material with the minor involvement of juvenile mantle inputs (<55%). SIMS zircon U–Pb analyses of two samples indicate that the crystallization of the Linzhi granitoid took place around 26Ma, implying that the crust of the Lhasa terrane was already thickened up to 50km prior to emplacement of the adakitic rocks. 40Ar/39Ar ages for biotites, and the presence of magmatic epidote, suggest the granitoid was intruded at mid-crustal depths, indicating that the eastern Lhasa terrane experienced a pulse of rapid uplift in the interval from 26 to 22Ma. The geochemical features of the Linzhi adakitic rocks are significantly different from those of Eocene adakitic rocks from the north Himalayan belt, and this suggests that we can rule out the possibility of crustal thickening in the eastern part of Lhasa terrane, caused by impingement of the Indian lower crust. Post-collisional (26–10Ma) adakitic rocks occur within an E–W-trending magmatic belt that runs parallel to the Yarlung–Tsangpo suture in the Lhasa terrane. These rocks have distinctive variations in geochemistry along the strike of the Lhasa terrane, indicating that the lower crust is isotopically heterogeneous from west to east along the terrane. These geochemical variations probably result from variable degrees of input, along strike, of juvenile mantle-derived melts into an old lower crust. The middle part of the Lhasa terrane is marked by a juvenile lower crust that contains large amounts of mantle-derived melt, underplated during Neo-Tethyan oceanic crust subduction. In contrast, the lower crust below the western and eastern parts of the terrane is relatively ancient. Therefore, crustal thickening caused by underplating of mantle-derived magmas could play an important role in the middle segment of the terrane, whereas crustal compression and shortening as a result of the collision of the Indian and Asian plates could be the major cause for crustal thickening in the western and eastern segments. [Copyright &y& Elsevier]

Abstract Cenozoic high–Sr/Y shoshonites in western Yunnan, China, are spatially and temporally associated with porphyry deposits and mafic volcanic rocks that formed at a post–collisional setting. However, the petrogenesis of these rocks and the origins of the associated mineralization remain unclear. Here we present new geochemical data for the high–Sr/Y shoshonites and associated mafic microgranular enclaves (MMEs) in the Jinshajiang–Ailaoshan mineralization belt, which formed as a result of India–Asia collision during the Cenozoic. Both fertile and barren shoshonitic porphyries were emplaced during the Eocene–Oligocene (32–37 Ma) and are characterized by enrichment in large–ion lithophile elements (LILE), depletion in high field strength elements (HFSE), high K 2 O (4–6 wt%), Sr contents (674–1370 ppm), and low Y contents (7–18 ppm). The barren Zhanhe, Yongsheng, Songgui, and Jianchuan, and fertile Machangqing (Cu–Au–Mo mineralization) porphyry intrusions have variable zircon εHf(t) values of −6 to +9 and old T DM2 ages of 1433 to 900 Ma. However, the barren Shigu porphyry intrusion yields relatively positive zircon εHf(t) values (−4 to +8) and younger T DM2 ages (903–631 Ma). These features indicate that the Shigu intrusion was derived from late Permian juvenile lower crust, and the other high Sr/Y shoshonites were derived mainly from Neoproterozoic juvenile lower crust. Fertile and barren porphyries have variable whole–rock εNd(t) values (−5 to −0.7) and (87Sr/86Sr) i ratios (0.70595–0.70788) that are within the range of coeval mafic magmas in western Yunnan. The MMEs comprise mafic enclaves and andesitic enclaves that formed during the Eocene (34–35 Ma) and have spheroidal shapes, igneous textures and contain acicular apatites. This indicates that the MMEs are globules of coeval mafic magma that was injected into and mixed with the host shoshonitic magma. The enclaves show low TiO 2 contents (0.7–0.8 wt%), high MgO (6–9 wt%), Cr (184–450 ppm) and Ni contents (98–157 ppm), positive LILE anomalies, marked negative HFSE anomalies, a narrow range of εNd(t) values (−1.2 to −0.6), and (87Sr/86Sr) i values of 0.70556–0.70635. The andesitic enclaves show adakitic geochemical affinities and have similar zircon εHf(t) values (−2.7 to +2.5) to the host porphyries, whereas, the mafic enclaves have relatively negative zircon εHf(t) values (−8.7 to +1.5), similar to enriched mantle. These evidences suggest the high−Sr/Y shoshonites were produced by partial melting of juvenile lower crust mixed with ultrapotassic or potassic mafic magmas as represented by the andesitic enclaves. The mafic enclave melts were derived from enriched mantle metasomatized by slab–derived fluids, which elevated the Mg#, Cr, Ni contents of the host porphyries at Machangqing, Zhanhe and Yongsheng. Zircon saturation temperatures (T Zr) of the high–Sr/Y shoshonitic rocks range from 735 to 777 °C and indicate the shoshonites were derived mainly from water–fluxed melting of lower crust. The Manchangqing fertile intrusion had a high oxidation state (zircon Ce4+/Ce3+ = 38–180, average = 91) and was derived by mixing between juvenile lower–crustal melts and voluminous coeval lamprophyres. In contrast, the barren Jianchuan, Songgui, Shigu, Yongsheng and Zhanhe high–Sr/Y shoshonites formed by partial melting of juvenile lower crust and some mixing with mafic lavas, and are characterized by low oxygen fugacity (zircon Ce4+/Ce3+ = 0.5–77, average = 20). As such, we suggest the mafic magmas triggered water–fluxed, moderate–degree partial melting of the lower crust and caused amphibole breakdown during melting. This process could not provide enough water for the formation of porphyry Cu-Au deposits in western Yunnan, and therefore formed low–fO 2 , relatively low–H 2 O, and barren high–Sr/Y magmas. However, ultrapotassic magmas (e.g., lamprophyres) with high H 2 O are able to trigger intense water–fluxed, partial melting of metal–fertilized lower crust, which generated high–fO 2 , relatively high–H 2 O, fertile, high–Sr/Y shoshonitic magmas in this intracontinental setting. Highlights • The high-Sr/Y shoshonites were emplaced during the Eocene-Oligocene. • The shoshonites were derived from heterogeneous juvenile lower crust. • The MMEs are dominated by mafic enclaves and andesitic enclaves. • Fertile shoshonites were formed by intense water-fluxed partial melting. • Barren shoshonites were originated from moderate water-fluxed partial melting. [ABSTRACT FROM AUTHOR]

Northward Neo-Tethyan oceanic lithosphere subduction beneath southern Tibet in the Mesozoic–Early Cenozoic produced continental arc magmas in the ~ 1600 km-long Gangdese belt. The most voluminous magmatism occurred in the Paleocene–Eocene, and is characterized by extensive I-type calc-alkaline to high-K calc-alkaline Linzizong volcanic rocks, and coeval plutons. These rocks have been extensively studied in the eastern Gangdese belt (east of ∼ 89°E), but few data exist from the western Gangdese belt. New data for eleven samples of these rocks, combined with existing data from the literature, show that they are similar to the eastern Gangdese belt rocks, with relative depletions in Nb, Ta, P, and Ti, and enrichments in Rb, Ba, Th, U, K, Pb, Zr, and Hf on a primitive mantle-normalized trace element diagrams, typical of continental arc-related igneous rocks. However, compared to the east, western Gangdese igneous rocks range to higher K 2 O contents (up to 6.1 wt.%), higher ( 87 Sr/ 86 Sr) i ratios (up to 0.7151), and lower εNd i values (down to − 8.1), suggesting that an evolved crustal source was involved in arc magmatism. The Gangdese arc magmatism lasted to ~ 80 Ma, and has a gap or quiescent period afterwards. Starting at ~ 69 Ma, the arc magmatism initiated and shifted southward from ~ 30.5°N to ~ 29.5°N in southern Tibet with an abrupt change of India-Asia convergence rate. The magmas through the whole Gangdese belt at ~ 69–53 Ma are characterized by intermediate εNd i values (− 0.6 to + 4.0), positive εHf i values (+ 3.8 to + 7.1), intermediate δ 18 O values (+ 5.0‰ to + 6.5‰), and low Th/Y and La/Yb ratios (< 20). These magmas were likely derived from the mantle with crustal contamination by MASH process in response to Neo-Tethyan slab rollback as proposed by previous studies. The Sr–Nd–Hf–O isotopic compositions of Linzizong volcanic rocks and coeval intrusions are relatively homogeneous during ~ 69–53 Ma, but show a wide range at ~ 53–50 Ma. Zircon temperature values from these rocks are distinctively high during the latter period and whole rock Th/Y and La/Yb ratios increased significantly after ~ 50 Ma. We suggest that the high temperature and heterogeneous geochemistry of these magmas at ~ 53–50 Ma reflect Neo-Tethyan slab breakoff during India-Asia collision, which triggered asthenospheric mantle upwelling. Mantle derived magmas resulted in extensive heating, induced crustal melting, and generated magmas with variable isotopic compositions. Tibetan crust was significantly thickened after ~ 50 Ma. [ABSTRACT FROM AUTHOR]

The tectono-magmatic history of the Lüchun-Jinping microblock and its possible affinity with the Yangtze Craton are important elements for the reconstruction of Cenozoic plate tectonics in southeastern Tibet. In order to constrain the affinity and decipher the pre-Cenozoic paleopositon of the Lüchun-Jinping microblock, we focused on the petrogenesis of Eocene-Oligocene lamprophyres in the Lüchun-Jinping microblock. The lamprophyres yield zircon U Pb ages of 34.7–33.3 Ma and exhibit potassic-ultrapotassic features with elevated K 2 O/Na 2 O (1.4–4.0) ratios. They are characterized by high concentrations of compatible elements (e.g., Cr = 187–692 ppm, Ni = 31–218 ppm), large-ion-lithophile elements and light rare-earth elements enrichment, high-field-strength elements depletion, and high radiogenic isotopic values, i.e. (87Sr/86Sr) i = 0.7063–0.7078 and εNd(t) = −3.9 to −2.4. Combined with the low Nb/U ratios, these features suggest that the lithospheric mantle source was metasomatized by subduction-related fluids beneath the Lüchun-Jinping microblock. The relatively high Rb/Sr ratios and high heavy rare-earth element contents indicate that these lamprophyres were derived from partial melting of a phlogopite-bearing lherzolite within the spinel stability field. The parental magmas have experienced fractional crystallization of olivine and clinopyroxene during emplacement. Comprehensive comparisons between the lamprophyres from the Lüchun-Jinping microblock and the potassic-ultrapotassic mafic rocks from the western Yangtze Craton indicate that the Lüchun-Jinping microblock can be regarded as a dismembered part of the western Yangtze Craton due to continental extrusion and Cenozoic sinistral displacement. The compositional trends of the potassic-ultrapotassic mafic rocks suggest that the palaeogeographic position of the Lüchun-Jinping microblock was near the Dali area (west of the Binchuan) and close to the Jinshajiang suture zone before the Cenozoic. [Display omitted] • Mafic lamprophyre dykes from the Lüchun-Jinping microblock were emplaced at 35–33 Ma. • Geochemical compositions of mafic lamprophyres reflect an enriched SCLM domain. • The enriched SCLM domain was metasomatized by Proterozoic subduction-related fluids. • The Lüchun-Jinping microblock is a displaced part of western Yangtze Craton. • The pre-Late Eocene position of this microblock was near Dali and closer to the JSSZ. [ABSTRACT FROM AUTHOR]

Abstract Phanerozoic adakites typically represent modern analogues of Middle–Late Archean (3.5–2.5 Ga) tonalite–trondhjemite–granodiorite rocks (TTGs) due to their similarities in geochemical compositions. However, no Phanerozoic analogues have been reported for the Early Archean TTGs (>3.5 Ga), which are characterized by low Sr, Y and HREEs contents with low MgO and compatible elements contents, until recent years. The newfound Phanerozoic analogues have been defined as a new adakite subgroup named as "Jamaican–type adakites" (JTAs), and been regarded as the results of partial melting of subducted oceanic plateau crust. JTA–like magmas also occur in the Nuri complex, southern Tibet. We report whole–rock geochemical, Sr Nd isotopic data, zircon U Pb ages and in-situ Hf isotopic data for adakitic quartz diorites, quartz monzonites and JTA–like quartz porphyries in the Nuri complex. Zircon U Pb dating indicates that these rocks were emplaced in the Late Cretaceous at 93.5–92.1 Ma. Combined with the continuous variation trends of major and trace elements, the similarities in terms of whole–rock Sr Nd and zircon Hf isotopic compositions indicate that the three types of rocks are genetically related, while the quartz diorites should represent the relatively primitive melts. High MgO (5.00–5.41 wt%), Cr (138–159 ppm), Ni (65.9–96.8 ppm) contents and Mg# values (66–69), high ε Hf (t) values (10.5–11.9), ε Nd (t) values (3.7), and low (87Sr/86Sr) i values (0.7046–0.7050) indicate that the quartz diorites were derived from partial melting of subducted Neo–Tethyan oceanic slab, and subsequently underwent metasomatic reaction with the mantle wedge during their ascent. Quartz monzonites and JTA–like quartz porphyries were originated from quartz diorites by two stages of fractional crystallization. Low MgO and compatible elements contents of the quartz porphyries were caused by fractionation of hornblende, biotite, with minor magnetite and allanite, while low Sr contents and Sr/Y ratios were mainly controlled by plagioclase fractionation. This means that the JTA–like geochemical features of the quartz porphyries were generated by fractional crystallization from the adakites derived from partial melting of subducted slab, rather than directly derived from partial melting of subducted oceanic plateau. Therefore, various petrogenetic possibilities of the JTA–like magmas should be considered when using them as modern analogues. Graphical abstract Unlabelled Image Highlights • Nuri quartz diorites, quartz monzonites and quartz porphyries were synchronously emplaced at 93.5–92.1 Ma. • Quartz monzonites and JTA–like quartz porphyries were evolved from quartz diorites derived from subducted Neo–Tethyan slab. • JTA–like geochemical features can be generated by fractional crystallization of adakites. [ABSTRACT FROM AUTHOR]

In the world-class Gejiu Sn district, South China, tin mineralization is related to the Gejiu granitoids, which consist of porphyritic quartz monzonite, syenogranite, and porphyritic/equigranular biotite monzogranites. Zircon U Pb dating shows that these granitoids were emplaced at ca. 77.9–81.7 Ma. Close spatio-temporal associations, systematic element distribution patterns, and similar isotopic compositions, together reveal that they are consanguineous, and the porphyritic quartz monzonite represents relatively primitive magma. The occurrence of hornblende, high apatite Nd N /Nd N * (mostly > 1), and whole-rock evolutionary trends, collectively indicate that the Gejiu granitoids are fractionated I-type granites. Negative and fluctuant εHf(t) values (−13.3 to −3.8) reveal that their I-type affinities could be caused by a mixing source through partial melting of metasedimentary rocks with minor input of mantle-derived materials, which is supported by the presence of mafic microgranular enclaves (MMEs). Zircon and apatite elemental fingerprints, combined with Rayleigh fractional crystallization modeling, decipher a two-stage fractional crystallization of hornblende-dominated and feldspar-dominated. The negative correlation between whole-rock Fe 2 O 3 /FeO and Rb/Sr ratios suggests that the magmatic oxygen fugacity gradually decreases with fractional crystallization. High zircon saturation temperatures (∼ 835 °C) indicate that the additional heat from the mantle provided a higher melting temperature to trigger biotite breakdown reactions, which can effectively release Sn into the initial melt. Subsequently, tin in magma underwent a two-stage enrichment process under the conjunctive effect of the variation of fractionating phases and magmatic redox state. In the first stage, there is no significant Sn enrichment during hornblende, magnetite, and titanite fractionation, which is due to the compatibility of Sn with these Ti-bearing minerals under oxidized conditions. In the second stage, the dominant Sn-poor feldspar with limited Sn-sequestering biotite fractionation under more reduced conditions efficiently increases Sn concentration in the residual melt by a factor of ∼ 8, as demonstrated by systematic apatite geochemical data. The hysteretic crystallization of biotite prevents the premature sequestration of Sn and reserves adequate metals for eventual mineralization. Finally, fluid exsolution during the magmatic-hydrothermal transition loads magmatically enriched Sn into the hydrothermal system, leading to the formation of the Gejiu Sn district. [Display omitted] • The Gejiu granitoids are fractionated I-type granites. • Their magmatic oxygen fugacity gradually decreases with fractional crystallization. • They experienced a two-stage fractional crystallization process. • Feldspar-dominated fractionation results in significant enrichment of magmatic Sn. • Melt-fluid transition loads magmatically enriched Sn into the hydrothermal system. [ABSTRACT FROM AUTHOR]

Crust-mantle interaction is essential to the evolution of continental crust, but its type and mechanism remain controversial in continental collision zones. Post-collisional ultrapotassic and adakitic rocks in southern Tibet can provide important constraints on this issue. Here, we newly identify the Miocene ultrapotassic enclaves hosted within the coeval Renduo adakitic granitoids (17–16 Ma), an excellent target to decipher the origin of two types of magmatism and their genetic relationship. The petrographic observations, together with elemental and isotopic features, argue for a magma mixing process. In addition, the ultrapotassic enclaves are not only enriched in incompatible trace elements and radiogenic isotopes, but also characterized by Nd Hf isotopic decoupling and sub-chondritic Hf/Sm ratios, indicating that their lithospheric mantle source was metasomatized by previous Neo-Tethyan oceanic components rather than by Indian continental materials. The adakitic host granitoids have relatively low MgO and compatible trace element contents, as well as low but variable whole-rock ε Nd (t) and zircon ε Hf (t) values. This suggests that they were generated by partial melting of thickened ancient lower crust, with varying degrees of involvement of ultrapotassic melts and asthenosphere-derived juvenile components. In combination with previously published results, we propose that relative to the metasomatism of subcontinental lithospheric mantle by subducted Indian crustal materials, the interaction between mantle-derived melts and overlying Lhasa continental crust was much more significant during the collisional orogeny, and played an important role in the crustal growth and reworking of southern Tibet; besides, the extensive post-collisional magmatism was likely triggered by the tearing of subducted Indian slab. [Display omitted] • Miocene ultrapotassic enclaves are hosted in coeval Renduo adakitic granitoids. • Enriched mantle source of ultrapotassic enclaves was metasomatized by Neo-Tethyan subduction processes. • Host adakitic rocks were originated from thickened ancient lower crust with involvement of mantle-derived materials. • Extensive interaction exists between mantle-derived melts and overlying continental crust in collisional orogens. [ABSTRACT FROM AUTHOR]

A suite of lamprophyres, spatially associated with mafic lavas and potassic felsic intrusive rocks, was emplaced between 36.5 ± 0.2 and 33.7 ± 0.5 Ma (based on phlogopite 40 Ar/ 39 Ar dating) on the eastern side of the Ailao Shan-Red River shear zone in the western Yangtze Craton. These shoshonitic and ultrapotassic intrusive rocks post-date the ~ 60–55 Ma collisional event between the Indian and the Asian continents. They are characterized by: (1) enrichment in large-ion lithophile elements and light rare-earth elements with (La/Sm) n = 3.15–7.15; (2) strong positive Pb spikes; (3) depletion in high-field-strength elements (e.g. Nb/La = 0.08–0.98); (4) high initial 87 Sr/ 86 Sr (0.706–0.709) with negative εNd(t) values of − 10.5 to − 0.9; (5) old Nd model ages of 1542–945 Ma; and (6) radiogenic ( 207 Pb/ 204 Pb) i of 15.57–15.70 and ( 208 Pb/ 204 Pb) i (38.70–39.06). These features suggest that the mantle source was metasomatized by Proterozoic subduction beneath the Yangtze Craton. The lamprophyres have similar trace element patterns, and Sr–Nd–Pb isotope compositions, as coeval mafic lava, indicating a common source of metasomatized veined continental lithospheric mantle (CLM). Lower degree partial melting of metasomatic veins likely generated the lamprophyres, whereas the coeval mafic lava was likely derived from melting of phlogopite harzburgite. The lamprophyres and mafic lava have similar Sr–Nd isotope systematics as CLM-derived Neoproterozoic mafic rocks and Late Permian Emeishan low-Ti basalt in the region, indicating that they share the same Proterozoic source. We envisage that mantle plumes thermally eroded the Proterozoic metasomatized CLM beneath the western part of the Yangtze Craton during 825–750 Ma and 260–250 Ma, although residual metasomatized domains remained before being tapped by delamination after the India–Asia continental collision during the Paleogene period. [ABSTRACT FROM AUTHOR]