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Hui Luo - One of the best experts on this subject based on the ideXlab platform.
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late anisian radiolarian assemblages from the yarlung tsangpo Suture Zone in the jinlu area zedong southern tibet implications for the evolution of neotethys
Island Arc, 2019Co-Authors: Dishu Chen, Hui Luo, Xueheng Wang, Atsushi MatsuokaAbstract:Abundant Triassic radiolarian fossils were obtained from varicolored bedded cherts exposed in the Buruocang section near Jinlu village, Zedong, southern Tibet. The radiolarian-bearing rocks represent fragmented remnants of the Neotethys oceanic sediments belonging to the melange complex of the east part of the Yarlung-Tsangpo Suture Zone. Two new middle Late Anisian radiolarian assemblages recognized from this section named Oertlispongus inaequispinosus and Triassocampe deweveri, respectively, are compared with those known from Europe, Far East Russia, Japan, and Turkey. These Anisian radiolarian fossils are the first reported in southern Tibet and the oldest radiolarian record within the Yarlung-Tsangpo Suture Zone. They improve time constraints for the evolution of Neotethys in southern Tibet.
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new constraints on the india asia collision the lower miocene gangrinboche conglomerates yarlung tsangpo Suture Zone se tibet
Journal of Asian Earth Sciences, 2002Co-Authors: Jonathan C. Aitchison, Aileen M. Davis, Hui LuoAbstract:Abstract Lower Miocene conglomerates crop out along the length of the Yarlung Tsangpo Suture Zone on the southern margin of the Lhasa terrane. These conglomerates, known by various local names, are correlated herein as the Gangrinboche conglomerates. All units exhibit broadly similar stratigraphic histories and a basal depositional contact upon an eroded surface of rocks of the Lhasa terrane is ubiquitous. At most localities the tops of sections are either removed by erosion or truncated by north-directed thrusts. These conglomeratic molasse units developed in response to the India/Asia collision and record aspects of its development. In all units initial clast derivation was from the Lhasa terrane on the northern margin of the Yarlung Tsangpo Suture Zone. Up-section the first appearance of clasts derived from terranes within the Suture Zone and the northern margin of India, all of which lie to the south of any outcrops of Gangrinboche conglomerates, is observed. Although these units were previously thought to be Eocene, analysis of fossil and structural constraints indicates Early Miocene deposition. As development of the Gangrinboche conglomerates records a significant phase in the evolution of the India–Asia collision understanding of their age and stratigraphic evolution has wider implications for regional tectonic models.
M. Santosh - One of the best experts on this subject based on the ideXlab platform.
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multiple generations of mafic ultramafic rocks from the hongseong Suture Zone western south korea implications for the geodynamic evolution of ne asia
Lithos, 2013Co-Authors: Sanghoon Kwon, Sung Won Kim, M. SantoshAbstract:Abstract Dismembered mafic and serpentinized ultramafic bodies within the Hongseong Suture Zone of the Gyeonggi massif, southwestern Korean Peninsula are tectonically correlated with those from the Chinese Qinling–Dabie–Sulu collisional belt. We report sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon ages, detailed mineral compositions and whole rock geochemical data from the mafic rocks including eclogite and garnetite from the Hongseong Suture Zone. The zircon U–Pb data show multiple protolith ages corresponding to Neoproterozoic (ca. 815–770 Ma), Paleozoic (ca. 310 Ma) and Middle Triassic (ca. 240 Ma). The peak high-pressure and retrograde regional intermediate-pressure metamorphic events of Middle Triassic (ca. 240–230 Ma) are also recorded in zircons from the mafic rocks in the Hongseong Suture Zone. The ages and P–T estimates presented in this study match well with those of the peak ultra-high-pressure metamorphism in the Sulu area of China. Our results from the Hongseong Suture Zone provide important insights into the geodynamic history of the NE Asian region, with evidence for both Neoproterozoic subduction and a Paleozoic to Triassic subduction/accretion event.
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Multiple generations of mafic–ultramafic rocks from the Hongseong Suture Zone, western South Korea: Implications for the geodynamic evolution of NE Asia
Lithos, 2012Co-Authors: Sanghoon Kwon, Sung Won Kim, M. SantoshAbstract:Abstract Dismembered mafic and serpentinized ultramafic bodies within the Hongseong Suture Zone of the Gyeonggi massif, southwestern Korean Peninsula are tectonically correlated with those from the Chinese Qinling–Dabie–Sulu collisional belt. We report sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon ages, detailed mineral compositions and whole rock geochemical data from the mafic rocks including eclogite and garnetite from the Hongseong Suture Zone. The zircon U–Pb data show multiple protolith ages corresponding to Neoproterozoic (ca. 815–770 Ma), Paleozoic (ca. 310 Ma) and Middle Triassic (ca. 240 Ma). The peak high-pressure and retrograde regional intermediate-pressure metamorphic events of Middle Triassic (ca. 240–230 Ma) are also recorded in zircons from the mafic rocks in the Hongseong Suture Zone. The ages and P–T estimates presented in this study match well with those of the peak ultra-high-pressure metamorphism in the Sulu area of China. Our results from the Hongseong Suture Zone provide important insights into the geodynamic history of the NE Asian region, with evidence for both Neoproterozoic subduction and a Paleozoic to Triassic subduction/accretion event.
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Mega sheath fold of the Mahadevi hills, Cauvery Suture Zone, southern India: Implication for accretionary tectonics
Journal of the Geological Society of India, 2012Co-Authors: T.r.k. Chetty, T. Yellappa, D. P. Mohanty, P. Nagesh, V. V. Sivappa, M. Santosh, T. TsunogaeAbstract:The Mahadevi hills, located in the axial Zone of Cauvery Suture Zone, comprise a sequence of granulite facies rocks represented by garnet-bearing pyroxene granulites and quartzo-feldspathic gneisess interfolded with banded iron formations. Structural mapping with hand held GPS reveals that the Mahadevi hills constitute a mega sheath fold structure exposing well developed easterly plunging extension lineations. Depressional and culmination surfaces are well demarcated in association with elliptical map patterns. The development of the mega sheath fold structure is genetically related to the regional thrust-nappe tectonics, supporting the model of subduction-accretion-collisional history for the evolution of the Cauvery Suture Zone.
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ultrahigh temperature metamorphism in daqingshan inner mongolia Suture Zone north china craton
Gondwana Research, 2011Co-Authors: M. Santosh, Toshiaki Tsunogae, Shuwen Liu, Hisako ShimizuAbstract:Abstract The Inner Mongolia Suture Zone marks the Paleoproterozoic collisional boundary between the Yinshan Block and Ordos Block in the North China Craton. The ultrahigh-temperature (UHT) orogen developed within this collisional Suture reflects the extreme thermal conditions associated with the tectonic processes during the incorporation of the North China Craton within the Columbia supercontinent. Here we report the results from a systematic petrological and phase equilibria modeling study of sapphirine-bearing granulites from Daqingshan, a region within the central domain of the Inner Mongolia Suture Zone. The sapphirine–spinel–garnet–sillimanite–biotite-bearing granulites in Daqingshan occur typically as dark lenses or layers within spinel–garnet–sillimanite–biotite-bearing gneisses, and are associated with mafic granulites carrying orthopyroxene + clinopyroxene + plagioclase + calcic amphibole. The sapphirine in these rocks is magnesian ( X Mg = 0.73–0.79) and occurs in various microstructural associations such as: (1) matrix coarse-grain mineral in plagioclase aggregates, (2) subidioblastic mineral mantling spinel or in direct contact with spinel, (3) fine-grained phase in sillimanite, and (4) vermicular symplectitic aggregates with plagioclase. Garnet + plagioclase + sapphirine + sillimanite + ilmenite + inferred melt is considered to represent the peak assemblage in these rocks. We apply systematic phase equilibria analysis in the system Na 2 O–CaO–K 2 O–FeO–MgO–Al 2 O 3 –SiO 2 –H 2 O–TiO 2 –Fe 2 O 3 (NCKFMASHTO) to constrain the peak P–T conditions of the Daqingshan Mg–Al granulites. Our pseudosection analysis defines the stability of the peak assemblage at T > 970 °C at P > 11 kbar. The peak temperature derived from pseudosection analysis is broadly consistent with the temperature estimate from conventional thermometry of sapphirine–spinel pairs (ca. 940 °C). The extreme metamorphism recorded from the Mg–Al granulites from Daqingshan is also consistent with the occurrence of dry orthopyroxene + clinopyroxene + plagioclase, and orthopyroxene + pargasite + plagioclase in the associated mafic granulites, although conventional thermometry yields lower temperatures from these rocks (830–840 °C) marking the post-peak retrograde stage. Our data confirm UHT conditions in Daqingshan and indicate that the extreme metamorphism is of regional extent within the Inner Mongolia Suture Zone, in agreement with the model of ultra-hot metamorphic orogen developed within a Paleoproterozoic subduction–collision system.
Ian Metcalfe - One of the best experts on this subject based on the ideXlab platform.
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Lower Permian conodonts from Palaeo-Tethys Ocean Plate Stratigraphy in the Chiang Mai-Chiang Rai Suture Zone, northern Thailand
Gondwana Research, 2017Co-Authors: Ian Metcalfe, C.m. Henderson, Koji WakitaAbstract:Abstract Lower Permian (lower Sakmarian) conodonts are reported from a coherent section of Ocean Plate Stratigraphy, and from a limestone block in the Palaeo-Tethys Suture Zone between Lamphun and Lampang, south of Chiang Mai, northern Thailand. Conodont species from both the pelagic limestones of the OPS section and the limestone block are deep-water forms with distinctive biogeographic affinities comparable to faunas of the Urals and North American Mid-Continent. A new name, Chiang Mai-Chiang Rai Suture Zone, is here proposed for the Palaeo-Tethys Suture in northern Thailand that forms the boundary between the Sibumasu Terrane and the Sukhothai Arc terrane. The Inthanon Zone of northern Thailand is interpreted as representing a fold and thrust belt west of the Chiang Mai-Chiang Rai Suture Zone, which comprises Sibumasu Terrane continental margin rocks and remnant klippen of Chiang Mai-Chiang Rai Suture Zone rocks thrust as a nappe westward during the Triassic collision between Sibumasu and the Sukhothai Arc/Indochina Terrane.
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The Bentong-Raub Suture Zone, Permo-Triassic Orogenesis and Amalgamation of the Sibumasu and Indochina Terranes
Gondwana Research, 2001Co-Authors: Ian MetcalfeAbstract:The Bentong-Raub Suture Zone (Fig. 1) represents a segment of the main Devonian to Middle Triassic Palaeo-Tethys ocean and forms the boundary between the Gondwanaland-derived Sibumasu and Indochina terranes. Palaeo-Tethyan oceanic ribbon-bedded cherts in the Suture Zone range in age from Middle Devonian to Middle Permian and mClange includes Lower Carboniferous to Lower Permian chert and limestone clasts. This indicates that the Palaeo-Tethys opened in the Devonian and closed in the Late Triassic (Peninsular Malaysia segment).
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the bentong raub Suture Zone
Journal of Asian Earth Sciences, 2000Co-Authors: Ian MetcalfeAbstract:Abstract It is proposed that the Bentong–Raub Suture Zone represents a segment of the main Devonian to Middle Triassic Palaeo-Tethys ocean, and forms the boundary between the Gondwana-derived Sibumasu and Indochina terranes. Palaeo-Tethyan oceanic ribbon-bedded cherts preserved in the Suture Zone range in age from Middle Devonian to Middle Permian, and melange includes chert and limestone clasts that range in age from Lower Carboniferous to Lower Permian. This indicates that the Palaeo-Tethys opened in the Devonian, when Indochina and other Chinese blocks separated from Gondwana, and closed in the Late Triassic (Peninsular Malaysia segment). The Suture Zone is the result of northwards subduction of the Palaeo-Tethys ocean beneath Indochina in the Late Palaeozoic and the Triassic collision of the Sibumasu terrane with, and the underthrusting of, Indochina. Tectonostratigraphic, palaeobiogeographic and palaeomagnetic data indicate that the Sibumasu Terrane separated from Gondwana in the late Sakmarian, and then drifted rapidly northwards during the Permian–Triassic. During the Permian subduction phase, the East Malaya volcano-plutonic arc, with I-Type granitoids and intermediate to acidic volcanism, was developed on the margin of Indochina. The main structural discontinuity in Peninsular Malaysia occurs between Palaeozoic and Triassic rocks, and orogenic deformation appears to have been initiated in the Upper Permian to Lower Triassic, when Sibumasu began to collide with Indochina. During the Early to Middle Triassic, A-Type subduction and crustal thickening generated the Main Range syn- to post-orogenic granites, which were emplaced in the Late Triassic–Early Jurassic. A foredeep basin developed on the depressed margin of Sibumasu in front of the uplifted accretionary complex in which the Semanggol “Formation” rocks accumulated. The Suture Zone is covered by a latest Triassic, Jurassic and Cretaceous, mainly continental, red bed overlap sequence.
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the jinshajiang ailaoshan Suture Zone china tectonostratigraphy age and evolution
Journal of Asian Earth Sciences, 2000Co-Authors: Xiaofeng Wang, Ian Metcalfe, Ping Jian, Chuanshan WangAbstract:Abstract The Jinshajiang Suture Zone is important for enhancing our understanding of the evolution of the Paleo-Tethys and its age, tectonic setting and relationship to the Ailaoshan Suture Zone have long been controversial. Based on integrated tectonic, biostratigraphic, chemostratigraphic and isotope geochronological studies, four tectono-stratigraphic units can be recognized in the Jinshajiang Suture Zone: the Eaqing Complex, the Jinshajiang Ophiolitic Melange, the Gajinxueshan “Group” and the Zhongxinrong “Group”. Isotope geochronology indicates that the redefined Eaqing Complex, composed of high-grade-metamorphic rocks, might represent the metamorphic basement of the Jinshajiang area or a remnant micro-continental fragment. Eaqing Complex protolith rocks are pre-Devonian and probably of Early–Middle Proterozoic age and are correlated with those of the Ailaoshan Complex. Two zircon U–Pb ages of 340±3 and 294±3 Ma , separately dated from the Shusong and Xuitui plagiogranites within the ophiolitic assemblage, indicate that the Jinshajiang oceanic lithosphere formed in latest Devonian to earliest Carboniferous times. The oceanic lithosphere was formed in association with the opening and spreading of the Jinshajiang oceanic basin, and was contiguous and equivalent to the Ailaoshan oceanic lithosphere preserved in the Shuanggou Ophiolitic Melange in the Ailaoshan Suture Zone; the latter yielded a U–Pb age of 362±41 Ma from plagiogranite. The re-defined Gajinxueshan and Zhongxinrong “groups” are dated as Carboniferous to Permian, and latest Permian to Middle Triassic respectively, on the basis of fossils and U–Pb dating of basic volcanic interbeds. The Gajinxueshan “Group” formed in bathyal slope to neritic shelf environments, and the Zhongxinrong “Group” as bathyal to abyssal turbidites in the Jinshajiang–Ailaoshan back-arc basin. Latest Permian–earliest Middle Triassic synorogenic granitoids, with ages of 238±18 and 227±5–255±8 Ma , respectively, and an Upper Triassic overlap molasse sequence, indicate a Middle Triassic age for the Jinshajiang–Ailaoshan Suture, formed by collision of the Changdu-Simao Block with South China.
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The Bentong–Raub Suture Zone
Journal of Asian Earth Sciences, 2000Co-Authors: Ian MetcalfeAbstract:Abstract It is proposed that the Bentong–Raub Suture Zone represents a segment of the main Devonian to Middle Triassic Palaeo-Tethys ocean, and forms the boundary between the Gondwana-derived Sibumasu and Indochina terranes. Palaeo-Tethyan oceanic ribbon-bedded cherts preserved in the Suture Zone range in age from Middle Devonian to Middle Permian, and melange includes chert and limestone clasts that range in age from Lower Carboniferous to Lower Permian. This indicates that the Palaeo-Tethys opened in the Devonian, when Indochina and other Chinese blocks separated from Gondwana, and closed in the Late Triassic (Peninsular Malaysia segment). The Suture Zone is the result of northwards subduction of the Palaeo-Tethys ocean beneath Indochina in the Late Palaeozoic and the Triassic collision of the Sibumasu terrane with, and the underthrusting of, Indochina. Tectonostratigraphic, palaeobiogeographic and palaeomagnetic data indicate that the Sibumasu Terrane separated from Gondwana in the late Sakmarian, and then drifted rapidly northwards during the Permian–Triassic. During the Permian subduction phase, the East Malaya volcano-plutonic arc, with I-Type granitoids and intermediate to acidic volcanism, was developed on the margin of Indochina. The main structural discontinuity in Peninsular Malaysia occurs between Palaeozoic and Triassic rocks, and orogenic deformation appears to have been initiated in the Upper Permian to Lower Triassic, when Sibumasu began to collide with Indochina. During the Early to Middle Triassic, A-Type subduction and crustal thickening generated the Main Range syn- to post-orogenic granites, which were emplaced in the Late Triassic–Early Jurassic. A foredeep basin developed on the depressed margin of Sibumasu in front of the uplifted accretionary complex in which the Semanggol “Formation” rocks accumulated. The Suture Zone is covered by a latest Triassic, Jurassic and Cretaceous, mainly continental, red bed overlap sequence.
Jingsui Yang - One of the best experts on this subject based on the ideXlab platform.
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Magnetic properties of serpentinized peridotites from the Dongbo ophiolite, SW Tibet: Implications for Suture‐Zone magnetic anomalies
Journal of Geophysical Research: Solid Earth, 2017Co-Authors: Jianping Zheng, Bruce M. Moskowitz, Qingsheng Liu, Qing Xiong, Jingsui YangAbstract:Magnetic properties of a suite of variably serpentinized peridotites from the Dongbo ophiolite, SW Tibet (China), have been investigated to determine the magnetic signatures of Suture Zones. The degree of serpentinization (S) for these peridotites is mainly in the range of S 60% and S=20–30% serpentinized peridotites, indicating that peridotites with such degrees of serpentinization contribute to the aeromagnetic anomalies within the Yarlung-Zangbo Suture Zone in south Tibet.
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magnetic properties of serpentinized peridotites from the dongbo ophiolite sw tibet implications for Suture Zone magnetic anomalies
Journal of Geophysical Research, 2017Co-Authors: Jianping Zheng, Bruce M. Moskowitz, Qingsheng Liu, Qing Xiong, Jingsui YangAbstract:Magnetic properties of a suite of variably serpentinized peridotites from the Dongbo ophiolite, SW Tibet (China), have been investigated to determine the magnetic signatures of Suture Zones. The degree of serpentinization (S) for these peridotites is mainly in the range of S 60% and S=20–30% serpentinized peridotites, indicating that peridotites with such degrees of serpentinization contribute to the aeromagnetic anomalies within the Yarlung-Zangbo Suture Zone in south Tibet.
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crustal structure of the indus tsangpo Suture Zone and its ophiolites in southern tibet
Gondwana Research, 2015Co-Authors: Yildirim Dilek, Jingsui Yang, Fenghua Liang, Fei Liu, Zhihui Cai, Hanwen DongAbstract:Abstract The > 2000-km-long Indus–Tsangpo Suture Zone (ITSZ) in southern Tibet contains remnants of Neotethyan oceanic lithosphere, ophiolitic melanges, flysch units and continental rocks, and has been interpreted as the boundary between the India and Eurasia plates. We have used field-based structural analyses and geological mapping in five key ophiolite massifs (Luobusa, Zedang, Xigaze, Jiding and Dongbo) and petrofabric studies of core samples recovered through the Luobusa Scientific Drilling Project to document the structural architecture and the deformation history of the ITSZ. The structural and kinematic analyses of the Suture Zone units indicate the occurrence of superposed deformation fabrics, which developed first during the ophiolite emplacement and then during the subsequent India–Asia continental collision. The suprasubduction Zone ophiolites were emplaced southward onto the northern margin of the proto-Indian plate in the late Cretaceous. The continental collision between the ophiolite-laden proto-Indian margin and the Lhasa terrane of the Eurasian plate in the early Paleogene resulted in backthrusting and inversion of the structural order of the ITSZ. The ophiolite massifs, ophiolitic melanges and flysch units were thrust northward as nappe sheets over the Eocene and younger forearc basin strata. The ITSZ shows, therefore, a complex structural anatomy characterized by both south and north-directed thrust faults, and ductile and brittle deformation fabrics.
Aileen M. Davis - One of the best experts on this subject based on the ideXlab platform.
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Conglomerates record the tectonic evolution of the Yarlung-Tsangpo Suture Zone in southern Tibet
Geological Society London Special Publications, 2004Co-Authors: Aileen M. Davis, Jonathan C. Aitchison, Badengzhu, Luo HuiAbstract:The histories of individual conglomeratic units along the Yarlung-Tsangpo (River) Suture Zone in southern Tibet reflect significant phases in the Mesozoic to Cenozoic tectonic evolution of this area. Several temporally distinct conglomerate units are recognized along the Suture, and their detailed examination permits analysis of the collision between India and Asia. Upper Jurassic to Lower Cretaceous conglomerates crop out within the Sangri Group along the southern Lhasa terrane. They are dominated by limestone and andesitic volcanic cobbles derived entirely from the Lhasa terrane. These rocks have experienced amphibolite facies metamorphism, and exhibit a strong penetrative regional foliation. Thick successions of the Palaeocene Liuqu Conglomerate crop out within the Suture from Xigaze to Lhaze. They contain detritus sourced from intra-oceanic terranes associated with the Suture Zone, as well as clasts of Indian affinity, while Lhasa and Xigaze terrane-derived material is notably absent. These conglomerates record an early Suture Zone event prior to India-Asia collision. Uppermost Oligocene to Lower Miocene 'Gangrinboche facies' conglomerates crop out on the southern edge of the Lhasa terrane along the length of the Suture. Several correlative units within this facies exhibit broadly similar stratigraphic histories. A basal depositional contact upon an eroded Lhasa terrane surface is ubiquitous with initial clast derivation from the north. Up-section, the first arrival of coarse-grained, Suture-Zone and India-derived clasts, is abrupt. These southerly derived clasts predominate by the top of most sections. An a really restricted succession of gently dipping Late Neogene ultramafic breccias unconformably overlies folded Liuqu Conglomerate near Quanggong. Other Neogene sediments are extensive west of Mount Kailas. Deposition of coarse clastic sediments is presently continuing along the length of the Yarlung Tsangpo. Discrimination and detailed investigation of each of these units will improve our understanding of the evolution of the India-Asia collision.
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new constraints on the india asia collision the lower miocene gangrinboche conglomerates yarlung tsangpo Suture Zone se tibet
Journal of Asian Earth Sciences, 2002Co-Authors: Jonathan C. Aitchison, Aileen M. Davis, Hui LuoAbstract:Abstract Lower Miocene conglomerates crop out along the length of the Yarlung Tsangpo Suture Zone on the southern margin of the Lhasa terrane. These conglomerates, known by various local names, are correlated herein as the Gangrinboche conglomerates. All units exhibit broadly similar stratigraphic histories and a basal depositional contact upon an eroded surface of rocks of the Lhasa terrane is ubiquitous. At most localities the tops of sections are either removed by erosion or truncated by north-directed thrusts. These conglomeratic molasse units developed in response to the India/Asia collision and record aspects of its development. In all units initial clast derivation was from the Lhasa terrane on the northern margin of the Yarlung Tsangpo Suture Zone. Up-section the first appearance of clasts derived from terranes within the Suture Zone and the northern margin of India, all of which lie to the south of any outcrops of Gangrinboche conglomerates, is observed. Although these units were previously thought to be Eocene, analysis of fossil and structural constraints indicates Early Miocene deposition. As development of the Gangrinboche conglomerates records a significant phase in the evolution of the India–Asia collision understanding of their age and stratigraphic evolution has wider implications for regional tectonic models.
