Browsing by Author "Athokpam Krishnakanta Singh"

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Evidence of intraplate magmatism and subduction magmatism during the formation of Nagaland–Manipur Ophiolites, Indo–Myanmar Orogenic Belt, north-east India
(John Wiley and Sons Ltd, 2022) Sashimeren Imtisunep; Athokpam Krishnakanta Singh; Rajkumar Bikramaditya; Shoraisam Khogenkumar; Monika Chaubey; Naveen Kumar
Mafic extrusive rocks (basalts) and intrusive rocks (gabbros) from the Nagaland–Manipur Ophiolite (NMO) of the Indo–Myanmar Orogenic Belt (IMOB), north-east India, are investigated to understand their magmatic evolution in diverse tectonic environments. Basalts are distinguished into two types: basalt-I and basalt-II. Basalt-I type shows the sub-alkaline character with Nb/Y < 0.50, low Nb/Th (2.36–7.94), and low to moderate La/Sm (1.00–4.12) indicating derivation from a slightly enriched mantle source and also supported by their enriched LREE pattern with flat HREE. They are depleted in HFSEs (Nb and Ti) but enriched in U and Pb, which is indicative of a typical subduction origin derived from an MORB-type mantle source. Investigated samples of basalt-II and gabbros have an equal composition with alkaline characteristics. They have Nb/Y > 0.50, high Nb/Th (8.38–13.37), and highly enriched LREE (La/Sm = 4.41–6.35) pattern. They show typical Ocean Island Basalt (OIB) characters of a plume source. The two sets of basalts and gabbros found in this study have no sign of genetic relationship, and therefore, it strongly suggests that they were derived from two different mantle sources of a plume and a subduction zone mantle wedge. Our study supports the theory that the NMO has records of different magmatic episodes produced ranging from plume-related magmatism, to divergent and convergent plate magmatism that were generated at diverse tectonic settings. © 2022 John Wiley & Sons Ltd.
Evidence of melt– and fluid–rock interactions in the refractory forearc peridotites and associated mafic intrusives from the Tuting–Tidding ophiolites, eastern Himalaya, India: Petrogenetic and tectonic implications
(John Wiley and Sons Ltd, 2021) Amrita Dutt; Athokpam Krishnakanta Singh; Rajesh K. Srivastava; Govind Oinam
We present a comprehensive geochemical data set of whole-rock geochemistry and mineral phases from the mantle peridotites and mafic intrusives of the Tuting–Tidding Suture Zone (TTSZ) ophiolites, eastern Himalaya, north-east India. Modal mineralogy, low Al2O3 and CaO, high Cr# of Cr-spinels, and forsterite number (Fo90–92) in primary olivine indicate the highly refractory nature of the TTSZ peridotites. LREE-enriched patterns, cumulative olivines in dunites, and Cr-spinel and olivine compositions further suggest that the peridotites were subjected to high-temperature melt–rock interaction from a percolating boninitic melt in the nascent forearc of an intra-oceanic subduction zone. The associated mafic intrusives are tholeiitic in nature and their geochemical characteristics [∑REE = 23.34–59.12; nearly flat rare earth elements (REE) pattern (LaN/YbN = 1.49–2.58); negative anomalies of Nb and Ti] show mid-oceanic ridge basalt affinity. Trace elemental modelling of the mafic intrusives along with their mineralogy and geochemistry suggests that they formed due to different degrees of partial melting with the involvement of a subduction component in the spreading regime of the forearc region. Based on the presence of hydrous minerals like Cr-chlorite and tremolite in the peridotites and P–T modelling (525–575°C, 1.05–1.09 GPa) of the mafic intrusives, it is considered that TTSZ ophiolites underwent low-temperature metamorphism by fluid–rock interaction either during the later phase of subduction (in a cool mature subduction zone) or during Himalayan Orogeny. We also infer that the TTSZ ophiolites resemble other Neo-Tethyan ophiolites of the Indus-Tsangpo Suture Zone in terms of their geochemical and petrogenetic aspects. © 2020 John Wiley & Sons Ltd.
Formation of the associating high-Al and high-Cr chromitites in the Nagaland-Manipur Ophiolites in northeast India
(Taylor and Francis Ltd., 2025) Monika Chaubey; Athokpam Krishnakanta Singh; Sashimeren Imtisunep; Ibrahim Uysal; Birendra Pratap Singh; Manavalan Satyanarayanan; Bendangtola Longchar; Shoraisam Khogenkumar
The Nagaland-Manipur ophiolites (NMO), part of the Phanerozoic (538.8–0 Ma) Tethyan ophiolites, occur in the NNE-SSW trending Indo-Myanmar Orogenic Belt (IMOB), northeast India. The NMO hosts both high-Al (0.46 < Cr# < 0.53) and high-Cr chromitites (0.71 < Cr# < 0.79). These chromitite bodies are hosted in lherzolite, harzburgite, and dunite and show various textures, including massive, disseminated, nodular, and granular. The high-Al chromitite compositions in conjunction with the calculated Al2O3[melt] (15.66–16.39 wt.%), TiO2[melt] (0.65–0.94 wt.%), and FeO/MgO[melt] (0.65–0.83 wt.%) values indicate that they were derived from the tholeiitic melt that formed at the mid-ocean ridge centre through low-degree partial melting. In contrast, the high-Cr chromitites, coupled with the Al2O3[melt] (11.24–12.99 wt.%), TiO2[melt] (0.21–0.33 wt.%), and FeO/MgO[melt] (0.58–1.54) values show similar geochemical affinities to those derived from boninitic melts produced by partial melting of already depleted mantle due to the subduction of oceanic plate in a supra-subduction zone environment. The total platinum group element (PGE) contents (60–190 ppb) of high-Al chromitites are lower than the total PGE contents (118–2341 ppb) in high-Cr chromitites. Chondrite-normalized PGE patterns in high-Al chromitites are flat from Os to Rh and negatively sloping from Rh to Pd, whereas high-Cr chromitites show strongly fractionated chondrite-normalized PGE patterns. Total PGE contents and low Pd/Ir ratios (0.02–0.64) of chromitites are consistent with typical ophiolitic chromitites. Mineral chemistry and PGE systematics suggest that NMO chromitites were generated in two separate tectonic settings. Thus, we argue that the upper mantle of the NMO of the IMOB has been modified by a substantial amount of supra-subduction zone components after initially being formed in a mid-ocean ridge tectonic environment. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
Magma heterogeneity in the generation of ophiolitic mafic rocks on the eastern flank of the Indian plate
(Science Press, 2025) Sashimeren Imtisunep; Athokpam Krishnakanta Singh; Monika Chaubey; Rajkumar Bikrmaditya Singh; Bendangtola Longchar; Shoraisam Khogenkumar; Amrita Dutt
Subduction polarity reversal typically occurs in intra-oceanic arc settings; the existence of an ancient intra-oceanic arc and its associated back-arc system within the Neotethyan plate has been deliberated. In this study, we investigate the possible role of subduction initiation of polarity reversal in the formation of Nagaland-Manipur ophiolite (NMO), evaluate the petrological and geochronological data and compare it with the neighboring natural examples of subduction polarity reversal of the Andaman-Nicobar ophiolite (ANO). The ancient intra-oceanic arc, namely the Incertus-Woyla Arc, and its associated back-arc remnant have been correlated with the back-arc mafic of the ANO. We found that the geochemical signatures of mafic rocks of NMO and ANO are comparable, and the available geochronology data of ~ 145 Ma from the NMO basalt and chert fit well with the evolution and formation of the intra-oceanic arc, i.e., Incertus-Woyla Arc. The evolution and age of the Incertus-Woyla Arc are between 135 and 150 Ma. Although the oldest age of the ANO has been reported from metamorphic sole at about 106.4 and 105.3 Ma, the back-arc affinity of the amphibole has been credited to the back-arc spreading that occurred behind the Woyla Arc. Previous paleomagnetic and geochronological studies have suggested that the development of the back-arc basin behind the Incertus-Woyla Arc was a result of divergent double subduction. Therefore, we have inferred a similar scenario for the development of the back-arc affinity rocks of the NMO behind the Incertus-Woyla Arc and the reinterpretation for the evolution of the supra-subduction zone affinity rocks of NMO and ANO during subduction initiation after subduction polarity reversal. © The Author(s), under exclusive licence to Science Press and Institute of Geochemistry, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2025.
Magmatism in the Siang window of the Eastern Himalayan Syntaxis, NE India: a vestige of Kerguelen mantle plume activity
(Geological Society of London, 2022) Athokpam Krishnakanta Singh; Govind Oinam; Sun-Lin Chung; R.K. Bikramaditya; Hao-Yang Lee; Mallickarjun Joshi
We report new U–Pb zircon ages for mafic plutonic (gabbro) and volcanic (andesite) rocks, along with the whole-rock chemistry of a mafic–felsic suite of volcanic rocks from the Siang window of the Eastern Himalayan Syntaxis, NE India. Field relationships, and mineralogical and geochemical characteristics, of the studied mafic–intermediate–felsic rocks suggest their co-magmatic linkage that was generated in an extensional tectonic environment. Incompatible trace elements and low concentrations of large ion lithophile elements (LILEs) and REE behaviour reflect both the enriched nature of the mafic rocks and the limited influence of crustal contamination in their genesis. Partial melting and fractional crystallization processes have played a major role during the genesis of these felsic volcanics from the parental mafic magma. The laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb ages suggest that the mafic plutonic rock was emplaced at c. 121.18 + 1 Ma and intermediate volcanic rock was emplaced at c. 135.48 + 0.50 Ma during the Early Cretaceous period. The new ages are consistent with earlier reported zircon U–Pb ages (133.0 + 1.9–130.7 + 1.8 Ma) of felsic volcanic rocks from the present study area. Our new field observations, and mineralogical and geochemical characteristics, in conjunction with the U–Pb isotopic database suggest that the major magmatic event in the core of the Siang window of the Eastern Himalaya is coeval with the Raj-mahal–Sylhet–Mikir–Shillong flood basalts of eastern and northeastern India, and the Comei–Bunbury Large Igneous Province of southeastern Tibet and SW Australia. These events are related to the break-up of eastern Gondwana and outbreak of the Kerguelen plume. © 2021 The Author(s).
New constraints on the tectono-magmatic evolution of the Tidding-Mayodia ophiolites, eastern Himalaya, northeast India
(John Wiley and Sons Ltd, 2022) Athokpam Krishnakanta Singh; Amrita Dutt; Bibhuranjan Nayak; Raj Kumar Bikramaditya; Govind Oinam; Satyajeet S. Thakur; Rajesh K. Srivastava; Shoraisam Khogenkumar; Manoj Kumar
The Tidding-Mayodia ophiolites (TMO) exposed along the Lohit and Dibang river valleys in eastern Himalaya that have been considered as the extension of the Indus-Tsangpo Suture Zone ophiolites are revisited to review their petrogenetic-tectonic origin. The ophiolites consist of depleted harzburgite and dunite with lesser amounts of mafic rocks (gabbro intrusives, mafic dykes) and carbonates. The serpentinized peridotites consist of antigorite, lizardite, olivine, Cr-spinel, and bastite with minor sulfide minerals. From SEM-EDS studies, sulfide minerals were observed to be associated mainly with magnetites. The main sulfide mineral is pentlandite with minor millerite that exists as inclusions inside the pentlandite grains. Elemental mapping of these sulfides shows that they are mainly Ni-(Co-)-bearing sulfides. The olivines are highly forsteritic (Fo = 95–96) while the Cr-spinels show distinct Cr-magnetite rims with a chromite core (Cr# = ~93). The serpentinized peridotites have whole-rock compositions of SiO2 <47 wt% and high MgO (>36.37 wt%) and low Al2O3 (<1.21 wt%), CaO (<0.82 wt%), indicating the depleted nature of the parent rocks. Highly fractionated LREEs as compared to HREEs [(La/Yb)N = 2.62–13.22], and REE and Cr spinel chemistry modelling suggests that the studied peridotites have formed from ~22% partial melting of a depleted spinel lherzolite source which later underwent interactions with a high-temperature silicate melt that caused enrichment in LREE and Cr of spinels. The parental melt compositions of Cr spinel yield their formation during arc tectonism (Al2O3melt = 6.28–7.65 wt%, FeO/MgO = 1.00–1.33). Furthermore, Mn and Zn concentrations in spinels, the occurrence of Cr magnetite rim in Cr-spinels, presence of secondary olivine with higher Fo (~98), and occurrence of low-temperature re-equilibrated sulfide minerals, indicate that the rocks were subject to low-temperature metamorphism. Based on this evidence, combined with data from previous studies, a tectonic model has been proposed for the genesis of the studied ophiolites. This model shows that the ophiolites have formed from the entrapment of depleted N-MORB mantle in the mantle wedge of an intra-oceanic subduction zone. During the nascent forearc regime, this mantle wedge underwent interactions with high-temperature melts, which caused changes in their chemistry. Moreover, the rocks underwent interactions with low-temperature fluids in the mature forearc, which caused the formation of sulfides and metamorphozed these rocks. © 2021 John Wiley & Sons Ltd.
Petrogenesis and tectonic implications of the Late Cretaceous to Paleogene calc-alkaline volcanic rocks, Ladakh Himalaya
(Elsevier Ltd, 2023) Nongmaithem Lakhan Singh; Salim Akhtar; Athokpam Krishnakanta Singh; Birendra Pratap Singh; Ashima Saikia; Syed Hamim Jeelani
One of the most widespread volcanic suites exposed in the northwest Himalaya is the Khardung volcanic suite sandwiched between the Ladakh Batholith in the south and the Karakoram Batholith in the north. These volcanic rocks show a transition from andesite, dacite to more evolved rhyolite and have a calc-alkaline affinity. They display large ion lithophile elements (Rb, Sr, Ba, U, Pb) enrichment and depletion of high field strength elements (Nb, Ta, Hf, Ti) with increasing Eu negative anomaly from andesite to rhyolite. Bulk-rock Liquid Line of Descent (LLD) modelling shows that fractional crystallization played a dominant role in their petrogenesis. The calculated zircon saturation temperature (TZr) in andesitic magma (745 °C) is higher than the dacitic and rhyolitic magmas (682 °C). Andesites have zircon ages of 69–68 Ma, whereas more evolved dacite and rhyolite yield younger ages (59–64 Ma) that are consistent with their generation in the last stage of magmatism in an active continental marginal setting. Geochemical and geochronological findings of this study demonstrate that Khardung volcanic rocks were derived through two major magmatic events. These events occurred during the Late Cretaceous to the Paleocene Epoch due to the subduction of the Neo-Tethyan oceanic slab underneath the Eurasian plate boundary before the main collision between India and Eurasia. © 2023 Elsevier Ltd
Refertilization of depleted mantle peridotite in the Nagaland–Manipur ophiolite, north-east India: Constraints from PGE, mineral, and whole-rock geochemistry
(John Wiley and Sons Ltd, 2022) Monika Chaubey; Athokpam Krishnakanta Singh; Birendra P. Singh; Sashimeren Imtisunep; Amrita Dutt; Manavalan Satyanarayanan; Kshetrimayum Premi; Sethuraman G. Abhirami
This paper discusses whole-rock geochemistry, mineral chemistry, and platinum group element (PGE) systematics of depleted mantle rocks (harzburgite and dunite) from the northern part of Nagaland–Manipur Ophiolite (NMO), north-east India, to comprehend their source features, fractionation behaviour of PGE during magmatic evolution, and its tectonic origin. The studied ultramafic rocks are characterized by a low concentration of CaO (0.57–0.71 wt%), Al2O3 (0.18–0.92 wt%) with ∑REE of 1.135–2.702 ppm and high concentrations of MgO (38.70–44.21 wt%), Cr (1,843–4,572 ppm), and Ni (894–4,138 ppm). They show U-shaped REE patterns [LREE and HREE enrichment (La/Sm)N = 1.85–4.11, (Dy/Yb)N = 0.51–0.85]. Olivine ranges Fo 88.18 to Fo92.23, whereas Cpx and Opx range En44.84 to En47.89 and En86.37 to En93.37 respectively. The chrome spinel Cr# [Cr/(Cr + Al)] and Mg# [Mg/(Mg + Fe2+)] are 0.47–0.83 and 0.31–0.60, respectively, which indicates recrystallization from a boninitic magma in a Supra-Subduction Zone setting. Conventional thermometry indicates the equilibration temperatures of the dunite sample yielded high temperatures of ~850°C, suggesting their formation due to later interaction with high-temperature percolating melts. The PGE contents in harzburgite are low (125.6–142.8 ppb) as compared to the dunite (248–360 ppb). They have high PPGE/IPGE and negative Pt* (Pt/Pt* = 0.73) anomaly, which is characteristic of re-entry of PPGE into the system via reaction with percolating basaltic melt in the mantle wedge. Significantly higher concentration of PPGEs than IPGEs in the samples, indicating recrystallization of PPGEs with early sulphide fractionation. The presence of significant Rh and Pd enhancements relative to Pt in all samples suggests that Pt was removed during PGE fractionation. This could be one of the reasons for both harzburgite and dunite's sulphide undersaturation. PGE distribution in NMO ultramafic rocks was therefore validated as being governed by sulphide saturation in parental magma and altered not only by partial melting but also by fractionation during their production in the Supra-Subduction Zone environment. © 2022 John Wiley & Sons Ltd.
Significance of aegirine-bearing metabasic rocks in the metamorphic evolution of the Nagaland Accretionary Prism, northeast India
(John Wiley and Sons Ltd, 2022) Naresh C. Ghose; Athokpam Krishnakanta Singh; Amrita Dutt; Sashimaren Imtisunep
The ophiolite belt of Nagaland–Manipur states in Northeast India represents a segment of the ocean floor and upper mantle following eastward convergence of the Indian Plate with the Myanmar (Burmese) microplate during the Mesozoic. A variety of high-pressure metamorphic assemblages have been noted in the metabasics and metacherts from the Phanerozoic ophiolite belt in the central part of the Naga Hills, which constitute the Nagaland Accretionary Prism. The metabasics are represented by very low-grade assemblages of zeolite, prehnite-pumpellyite, greenschists, and high-pressure glaucophane schist and eclogite. We report the occurrence of aegirine-bearing metabasic rocks, previously not recorded in the region. The metabasics are strongly fractionated and show chemical affinity with low-K oceanic tholeiite. They are derived from a basic protolith of depleted mantle composition (viz. MORB). Pseudosection modelling reveals that aegirine formed at P–T conditions of c. 1.15 GPa and 490°C in the basic protolith in blueschist facies conditions. Similar P–T conditions have been reported from nearby localities, either as part of retrograde conditions or due to post-peak cooling changes in the different metamorphic assemblages. However, the P–T observed from our study does not follow the cooling or retrograde path of the reported metabasics. Therefore, we suggest that the aegirine-bearing metabasics might have formed at an earlier stage in the nascent forearc when temperatures were elevated enough to cause dehydration of the subducting slab to generate Na-rich fluid fluxes at ambient pressures. © 2021 John Wiley & Sons Ltd.
Zircon U–Pb ages and Hf isotopes of I-type granite from western Arunachal Himalaya, NE India: Implications for the continental arc magmatism in the Palaeoproterozoic supercontinent Columbia
(John Wiley and Sons Ltd, 2022) R.K. Bikramaditya; Sun-Lin Chung; Athokpam Krishnakanta Singh; Hao-Yang Lee; Leiphrakpam Lemba
We present integrated in situ zircon U–Pb and Hf isotope data, along with whole-rock and mineral chemistry data for the Salari granite of western Arunachal Himalaya to constrain its emplacement age, origin, and geodynamic evolution. The investigated Salari granites are high Fe2O3, CaO, and Nb, and low SiO2 and Rb/Sr ratio with fractionated rare earth element patterns ((Ce/Yb)N = 9.90–20.24) and minor negative Eu anomaly (Eu/Eu* = 0.69–0.94). They are metaluminous (molar A/CNK = 0.93–1.07) and have relatively similar FeOt/MgO ratio in biotite (1.58–1.60) to Mg-biotite, indicating their affinity with I-type granites. The enrichment of large-ion lithophile elements with highly depleted negative Nb anomalies is consistent with their origin in a subduction-related environment. Our zircon U–Pb ages suggest that the magmatic emplacement of the Salari granite took place between 1,791 and 1,768 Ma. The zircon grains have mostly negative εHf(t) values up to −5.5 and yield crustal Hf model ages from 2.4 to 2.8 Ga, suggesting the occurrence of a major crustal growth event in the Neoarchean and re-melting of the crust during the Palaeoproterozoic. Our new results, that is, zircon U–Pb age and Hf isotope data, in conjunction with the field observations and petro-mineralogical and geochemical characteristics, suggest that the Salari granite of eastern Himalaya was produced by partial melting of older metabasaltic/metatonalitic rocks in a continental arc setting of the supercontinent Columbia during the Palaeoproterozoic. © 2021 John Wiley & Sons Ltd.
Zircon U–Pb geochronology, Hf isotopic compositions, and petrogenetic study of Abor volcanic rocks of Eastern Himalayan Syntaxis, Northeast India: Implications for eruption during breakup of Eastern Gondwana
(John Wiley and Sons Ltd, 2020) Athokpam Krishnakanta Singh; Sun-Lin Chung; Rajkumar Bikramaditya; Hao-Yang Lee; Shoraisam Khogenkumar
This paper reports new zircon U–Pb ages and Hf isotopic compositions of felsic units of the Abor volcanic rocks (AVR) of Eastern Himalayan Syntaxis (EHS), Northeast India, and discusses their relationship to the Kerguelen plume activity. The AVR are bimodal and predominantly constituted by mafic rocks with minor felsic units. Mafic volcanics are identified as basalt and basaltic andesite with light rare earth elements (LREE) enriched and slightly depleted heavy rare earth elements (HREE) pattern without Eu anomalies. Low concentrations of LILE, high contents of Fe2O3, and other incompatible trace elements ratios reflect enriched nature of these mafic volcanics. Felsic volcanic rocks are dacitic to rhyolitic in composition, which have high REE content, high LREE/HREE, and pronounced negative Eu anomalies. Enriched LREE, high Th/Nb, Ce/Nb ratios, and variations in Rb/Zr, K/Rb, La/Sm ratios with negative anomalies of Ba, Nb, Sr, P, Ti in felsic rocks suggest substantial contribution of crustal contamination at the time of eruption. Zircons from felsic units yield an average U–Pb age of ~132 Ma and unradiogenic (ƐHf(t) < 0) Hf isotope values of −7.0 to −13.3 with model ages between 1.5 and 2.1 Ga, suggesting old crustal assimilation in their genesis. The AVR were emplaced in the continental rift tectonic setting, and depth of the magma source is confirmed as near spinel stability zone. The AVR are positively comparable with other flood basalts that were formed due to the Kerguelen plume activity. Therefore, our combined new geochemical and geochronological data show that the AVR were emplaced at early stage (~132 Ma) of eastern Gondwana breakup due to outbreak of the Kerguelen plume. This study thus supports the idea of the Kerguelen plume affecting a large area of Eastern India, Western Australia, and Antarctica during early stage of Gondwana breakup. © 2019 John Wiley & Sons, Ltd.
Zircon U–Pb geochronology, mineral and whole-rock geochemistry of the Khardung volcanics, Ladakh Himalaya, India: Implications for Late Cretaceous to Palaeogene continental arc magmatism
(John Wiley and Sons Ltd, 2020) Nongmaithem Lakhan; Athokpam Krishnakanta Singh; Birendra Pratap Singh; Koushik Sen; Mutum Rajanikanta Singh; Shoraisam Khogenkumar; Saurabh Singhal; Govind Oinam
In this study, we present new mineral and whole-rock geochemical data with zircon U–Pb ages of the Khardung volcanics (KV) from the western Himalaya and discuss their tectono-magmatic evolution. These volcanics are sandwiched between the Ladakh batholith and Karakoram batholith and classified as intermediate volcanics (basaltic andesite-andesite) and felsic volcanics (dacite-rhyolite). The intermediate volcanics are marked by low SiO2 (52.80–61.31 wt.%), enriched LREEs, and depleted HFSEs (Nb, Ti, Zr), whereas more evolved felsic volcanics exhibit quartz, K-feldspar, and plagioclase as dominant mineral phases and felsic compositions are characterized by high SiO2 (64.52–79.19 wt.%) content with pronounced negative Eu anomalies, enriched LREEs, and depleted HREEs and HFSEs (Nb, Ti). New zircon U–Pb ages of intermediate volcanics (andesite) yield 69.71 Ma, whereas felsic volcanics (rhyolites) range between 62.49 and 66.55 Ma, indicating that the Khardung magmatism overlaps with the last phase of the Ladakh batholith magmatism. Geochemical characteristics indicate that the KV were generated from a same parental magma source through fractional crystallization along with crustal assimilation from an older crust, and they show genetic affinity with the adjacent Ladakh batholith. Therefore, the KV and Ladakh batholith could be considered as a product of the mature stage arc magmatism generated during subduction of the Neo-Tethyan oceanic crust prior to the main collision between the Indian and Eurasian continents. © 2019 John Wiley & Sons, Ltd.