DOCSLIB.ORG

Jurassic Sedimentation in the South-Central Qiangtang Terrane Reveals Successive Terrane Collisions in Central Tibet

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Jurassic Sedimentation in the South-Central Qiangtang Terrane Reveals Successive Terrane Collisions in Central Tibet Research Paper GEOSPHERE Jurassic sedimentation in the south-central Qiangtang terrane reveals successive terrane collisions in central Tibet 1, 2 1 3 4 GEOSPHERE, v. 15, no. 2 Lin Li *, Carmala N. Garzione , Majie Fan , Xiaowei Li , and Xiangzhong Li 1Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, Texas 76019, USA 2Department of Earth and Environmental Sciences, University of Rochester, Rochester, New York 14627, USA https://doi.org/10.1130/GES01649.1 3State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China 4Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, China 10 figures; 1 set of supplemental files CORRESPONDENCE: [email protected] ABSTRACT the Tibetan Plateau, especially of its southern and central parts (England and Searle, 1986; Murphy et al., 1997; Kapp et al., 2005, 2007b). The collision be- CITATION: Li, L., Garzione, C.N., Fan, M.J., Li, X.W., Our limited knowledge of Mesozoic tectonism in the Tibetan Plateau has tween the Lhasa and Qiangtang terranes along the Bangong-Nujiang suture and Li, X.Z., 2019, Jurassic sedimentation in the south-central Qiangtang terrane reveals successive hindered understanding of its geologic evolution. This study uses zircon U-Pb (shortened to Bangong suture hereafter; Fig. 1) is one of the most prominent terrane collisions in central Tibet: Geosphere, v. 15, geochronology to refine regional chronostratigraphy and infer the Jurassic tectonic events that occurred in the Mesozoic history of the Tibetan Plateau no. 2, p. 433–449, https://doi.org/10.1130/GES01649.1. sedimentary-tectonic evolution of the Bangong suture and the south-central (Dewey et al., 1988; Yin and Harrison, 2000). Despite the many studies that Qiangtang terrane in the central plateau. During the late Early–early Middle have been conducted to understand the processes of the Lhasa-Qiangtang Science Editor: Shanaka de Silva Associate Editor: Michael H. Taylor Jurassic, fan delta and alluvial fan deposits sourced from the Amdo basement collision (Yin and Harrison, 2000; Zhang et al., 2012a; Zhu et al., 2013), the to the south occurred within the Amdo suture zone, as a result of collision timing and nature of the collision remain controversial. Received 15 December 2017 between the Amdo basement and Qiangtang terrane. Since the Bajocian of The current understanding of the timing and nature of the Lhasa-Qiangtang Revision received 26 September 2018 the Middle Jurassic, continued sea-level rise transformed the Qiangtang ter- collision can be classified into two hypotheses. One of the hypotheses suggests Accepted 14 December 2018 rane into a south-facing shallow continental shelf, and sedimentary detritus that the collision did not occur until the early Late Cretaceous (ca. 100 Ma), was predominantly sourced from the Hoh Xil and Kunlun terranes to the based primarily on the presence of: (1) 120–108 Ma basaltic rocks with ocean Published online 29 January 2019 north. The contemporaneous magmatic arc in southern Qiangtang terrane island affinity within the Bangong suture zone (Zhu et al., 2006; Liu et al., 2014; was most likely submerged in a marine setting and did not contribute much Zhang et al., 2014a; Fan et al., 2015); (2) 170–140 Ma and 130–100 Ma intrusive detritus to the Middle Jurassic strata. Starting from the early Late Jurassic, rocks in the southern Qiangtang terrane, presumably formed by continental a depositional hiatus occurred in the southern Qiangtang terrane, whereas arc magmatism associated with the northward subduction of the Meso-Tethys the shallow marine to deltaic deposition in the central Qiangtang terrane oceanic lithosphere (Li et al., 2014; Hao et al., 2016; Liu et al., 2017; Liu et al., received detritus not only from the Hoh Xil and Kunlun terranes to the north, 2018); and (3) 131–121 Ma deep-marine radiolarian deposits near Gaize in the but also from the magmatic arc in southern Qiangtang terrane to the south. Bangong suture zone (Baxter et al., 2009). The other hypothesis suggests a The arrival of abundant Jurassic arc-derived detritus in central Qiangtang diachronous collision from east in the Amdo area during the Middle–Late Ju- terrane since ca. 163 Ma was most likely caused by the early Late Jurassic rassic (ca. 174–145 Ma; Dewey et al., 1988; Leeder et al., 1988), to west in the initial collision between the Lhasa and Qiangtang terranes, which raised the Shiquanhe area during the Early Cretaceous (ca. 145–110 Ma; Matte et al., 1996). southern Qiangtang magmatic arc to be a source region. This latter hypothesis is mainly based on: (1) obduction of ophiolite fragments onto the northern margin of the Lhasa terrane during the Middle–Late Jurassic near Amdo (Yin and Harrison, 2000); and (2) structural analyses that indicate INTRODUCTION major Early Cretaceous shortening in the southern Qiangtang terrane near Shiquanhe and Gaize (Kapp et al., 2005; Raterman et al., 2014). The Tibetan Plateau is a collage of terranes that was assembled during In addition to the uncertainty in the timing of the Lhasa-Qiangtang colli- the Phanerozoic (Yin and Harrison, 2000); from south to north, they are the sion, the presence of the Amdo basement, with ophiolite fragments on both Himalaya, Lhasa, Qiangtang, Hoh Xil-Songpan-Ganzi (shortened to Hoh Xil its northern and southern sides (Coward et al., 1988; Fig. 1B), remains enig- hereafter), Kunlun-Qaidam, and Qilian terranes (Fig. 1A). Mesozoic tectonism, matic. Yin and Harrison (2000) considered the Amdo basement as a part of prior to the final Cenozoic India-Asia collision, contributed to the growth of the Lhasa terrane, and suggested that closure of the Meso-Tethys Ocean and collision between the Lhasa and Qiangtang terranes occurred to the north This paper is published under the terms of the *Current address: Géosciences Rennes, UMR–CNRS 6118, Université de Rennes 1, 35042 Rennes of the Amdo basement. To the contrary, Guynn et al. (2006) proposed that CC-BY-NC license. Cedex, France the Amdo basement was rifted from the Qiangtang terrane before the Early © 2019 The Authors GEOSPHERE | Volume 15 | Number 2 Li et al. | Jurassic terrane collisions in central Tibet Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/15/2/433/4663908/433.pdf 433 by guest on 26 September 2021 Research Paper 84 E 86 88 90 92 B Tr Hoh Xil terrane Tr K2-Ts JSS 35 JSS K2-Ts N Ts 35 Tr-Jr Tr-Jr N C-P Tuotuohe 34 Ts 34 Tr-Jr K2-Ts Ts Qiangtang Q Fig. 2A iangtan g terrane anti clinorium Yanshiping Ts 33 C-P Tr-Jr Shuanghu 33 Tr-Jr Tr-Jr Ts Tr-Jr Gaize Amdo BNS Ts 32 32 Nima BNS Amdo Jr-K Lhasa Jr-K basement terrane Jr-K Naqu 84 E 86 88 90 92 40 Abbreviations: A F N Qiangtang Paleozoic Central Qiangtang N asin AT QL Qi C-P im B l KL-QD: Kunlun-Qaidam metasedimentary rocks metamorphic rocks Tar KL-QD S ia n SCB: Sichuan Basin Qiangtang Mesozoic Late Cretaceous– ATF: Altyn Tagh strike- Tr-Jr K2-Ts Hoh X KLS sedimentary rocks Cenozoic sed. rocks 35 il slip fault Hoh Xil Triassic Cenozoic JS LMT: Longmenshan thrust Ts Qiangtang S Songpan Tr sedimentary rocks sedimentary rocks MBT: Main boundary thrust Ganzi B B T BNS: Bangong-Nujiang Lhasa Mesozoic Suture zone ophiolite NS Jr-K LM suture sedimentary rocks and sedimentary rocks Lhasa B 30 Hi IYS: Indus-Yurlong suture Qiangtang Eocene– ma IYS SC Amdo gneiss laya JSS: Jinshajiang suture Oligocene volcanics 400 km KLS: Kunlun suture MBT Mesozoic granites Thrust faults Indian QLS: Qilian suture 80 E 85 90 95 100 105 Figure 1. (A) Tibetan Plateau above the 2000 m elevation contour, showing major tectonic subdivisions and suture zones (dotted lines). Rectangular box shows location of B. (B) Simplified geologic map of the west-central Tibetan Plateau. Modified from Kapp et al. (2005). Rectangular box shows location of Fig. 2A. sed.—sedimentary. Jurassic and then collided with the Qiangtang terrane during the Early–Middle and detrital provenance can be distinctive in different tectonic settings; e.g., a Jurassic (ca. 190–170 Ma), which was followed by the major Lhasa-Qiangtang retroarc foreland basin would receive detritus mainly from the magmatic arc, collision to the south of the Amdo basement. whereas a passive continental margin basin would have major sediment sources The Qiangtang terrane holds the largest Jurassic marine deposits in the from the adjacent exposed continent. This study applies the zircon U-Pb geo- Tibetan Plateau. Previous sedimentological studies have suggested that these chronology method to both sandstone and igneous samples from the Jurassic Jurassic strata were deposited in shallow marine to marginal marine environ- sedimentary successions in the Amdo-Yanshiping area, south-central Qiangtang ments (Wang et al., 2001; Wang et al., 2010a). However, the tectonic setting of terrane (Fig. 2), to infer the history of the Lhasa-Qiangtang collision and the role these deposits is not well understood, with proposed models ranging from a that the Amdo basement played during the collision. We found that: (1) the retroarc foreland basin (Li et al., 2001) to a passive continental margin basin (Guo Amdo Formation received detritus mainly from the Amdo basement as a result et al., 2008) to a passive rift basin (Wang et al., 2010b). Depositional environment of late Early–early Middle Jurassic collision between the Amdo basement and GEOSPHERE | Volume 15 | Number 2 Li et al. | Jurassic terrane collisions in central Tibet Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/15/2/433/4663908/433.pdf 434 by guest on 26 September 2021 Research Paper 91.50 E 92.00 92.50 93.00 92.00 E 92.10 92.20 Q A Highway E B Tr3 E Q Q Tr3b J2-3 J C-P 2b J J2q Q Yanshiping C-P 2q Yanshiping 0 N J 0 N 3x J B 2q 16MZ01D 36.6 3.5 N Q J J2-3 Tr3 2b 3 J2-3 J3s 16MZ02D J2b J3 J3 x J2 x J2q J b 16MZ03D Q 2b J 0 0 10 20 km 3x J3K1x Q Q J2-3 J2-3 J2q J2b 0 Q J2-3 0 0 2.5 5 km Q 36.5 0 Tr J2-3 Tan ac J2b g e Q gul of a r 33.0 ang Q K2 91.60 E 91.80 92.00 e N K2 Pass Q Q Tr3t C J2ba J2-3 J2b 16AD03D 32.50 K2a Q Q 16QS01D J2 J2s K2d J2b 2d 2a K2d Q K K 5 J2s 3 50 K2d C 2.
Load more

Recommended publications
  • Two Contrasting Phanerozoic Orogenic Systems Revealed by Hafnium Isotope Data William J
    ARTICLES PUBLISHED ONLINE: 17 APRIL 2011 | DOI: 10.1038/NGEO1127 Two contrasting Phanerozoic orogenic systems revealed by hafnium isotope data William J. Collins1*(, Elena A. Belousova2, Anthony I. S. Kemp1 and J. Brendan Murphy3 Two fundamentally different orogenic systems have existed on Earth throughout the Phanerozoic. Circum-Pacific accretionary orogens are the external orogenic system formed around the Pacific rim, where oceanic lithosphere semicontinuously subducts beneath continental lithosphere. In contrast, the internal orogenic system is found in Europe and Asia as the collage of collisional mountain belts, formed during the collision between continental crustal fragments. External orogenic systems form at the boundary of large underlying mantle convection cells, whereas internal orogens form within one supercell. Here we present a compilation of hafnium isotope data from zircon minerals collected from orogens worldwide. We find that the range of hafnium isotope signatures for the external orogenic system narrows and trends towards more radiogenic compositions since 550 Myr ago. By contrast, the range of signatures from the internal orogenic system broadens since 550 Myr ago. We suggest that for the external system, the lower crust and lithospheric mantle beneath the overriding continent is removed during subduction and replaced by newly formed crust, which generates the radiogenic hafnium signature when remelted. For the internal orogenic system, the lower crust and lithospheric mantle is instead eventually replaced by more continental lithosphere from a collided continental fragment. Our suggested model provides a simple basis for unravelling the global geodynamic evolution of the ancient Earth. resent-day orogens of contrasting character can be reduced to which probably began by the Early Ordovician12, and the Early two types on Earth, dominantly accretionary or dominantly Paleozoic accretionary orogens in the easternmost Altaids of Pcollisional, because only the latter are associated with Wilson Asia13.
    [Show full text]
  • Initial Growth of the Northern Lhasaplano, Tibetan Plateau in the Early Late Cretaceous (Ca
    hu-B35124.1 2nd pages / 1 of 14 Initial growth of the Northern Lhasaplano in the early Late Cretaceous Initial growth of the Northern Lhasaplano, Tibetan Plateau in the early Late Cretaceous (ca. 92 Ma) Wen Lai1, Xiumian Hu1,†, Eduardo Garzanti2, Gaoyuan Sun1,3, Carmala N. Garzione4, Marcelle BouDagher Fadel5, and Anlin Ma1 1State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China 2Department of Earth and Environmental Sciences, Università di Milano-Bicocca, Milano 20126, Italy 3College of Oceanography, Hohai University, Nanjing 210098, China 4Department of Earth and Environmental Sciences, University of Rochester, Rochester, New York 14627, USA 5Department of Geological Sciences, University College London, London WC1E6BT, UK ABSTRACT INTRODUCTION Stable isotopes in lacustrine carbonates suggest that the basins surrounding the Gangdese Moun­ Constraining the growth of the Tibetan The Tibetan Plateau, with an average ele­ tains in the southern Lhasa terrane had reached Plateau in time and space is critical for test- vation of ~5000 m, is the world’s highest and an elevation >4500 m since India­Asia collision ing geodynamic models and climatic changes widest orogenic plateau, and exerts a major in­ (Ding et al., 2014). Low­temperature thermo­ at the regional and global scale. The Lhasa fluence on the Asian monsoon, global climate chronology reveal that the central and northern block is a key region for unraveling the early change, and regional distribution of living spe­ Lhasa terranes experienced rapid to moderate history of the Tibetan Plateau. Distinct from cies (Raymo and Ruddiman, 1992; Molnar et al., cooling and exhumation between 85 and 45 Ma the underlying shallow-marine limestones, 1993; An et al., 2001; Dupont­Nivet et al., 2007; (Hetzel et al., 2011; Rohrmann et al., 2012).
    [Show full text]
  • Paleomagnetic Constraints on the Mesozoic Drift of the Lhasa Terrane (Tibet) from Gondwana to Eurasia
    Paleomagnetic constraints on the Mesozoic drift of the Lhasa terrane (Tibet) from Gondwana to Eurasia Zhenyu Li1, Lin Ding1,2*, Peter C. Lippert3, Peiping Song1, Yahui Yue1, and Douwe J.J. van Hinsbergen4 1Key Laboratory of Continental Collision and Plateau Uplift (LCPU), Institute of Tibetan Plateau Research, Chinese Academy of Sciences (ITPCAS), Beijing 100101, China 2Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China 3Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112-9057, USA 4Department of Earth Sciences, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht, Netherlands ABSTRACT Himalaya (the northernmost continental rocks The Mesozoic plate tectonic history of Gondwana-derived crustal blocks of the Tibetan derived from the Indian plate) that collided with Plateau is hotly debated, but so far, paleomagnetic constraints quantifying their paleolati- Lhasa in the Eocene along the Indus-Yarlung tude drift history remain sparse. Here, we compile existing data published mainly in Chinese suture zone (Yin and Harrison, 2000; Hu et al., literature and provide a new, high-quality, well-dated paleomagnetic pole from the ca. 180 2015; Huang et al., 2015). Ma Sangri Group volcanic rocks of the Lhasa terrane that yields a paleolatitude of 3.7°S Most authors describe an ideal Wilson-cycle ± 3.4°. This new pole confirms a trend in the data that suggests that Lhasa drifted away scenario, wherein the blocks of the Tibetan Pla- from Gondwana in Late Triassic time, instead of Permian time as widely perceived. A total teau all drifted from India in Paleozoic to Meso- northward drift of ~4500 km between ca.
    [Show full text]
  • Post-Collisional Potassic Magmatism in the Eastern Lhasa Terrane, South Tibet: Products of Partial Melting of Mélanges in a Continental Subduction Channel
    Gondwana Research 41 (2017) 9–28 Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr Post-collisional potassic magmatism in the eastern Lhasa terrane, South Tibet: Products of partial melting of mélanges in a continental subduction channel Lihong Zhang a,b, Zhengfu Guo a,⁎,MaoliangZhanga,b, Zhihui Cheng a,b, Yutao Sun a,b a Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China b University of Chinese Academy of Sciences, Beijing 100049, China article info abstract Article history: Post-collisional, potassic magmatic rocks widely distributed in the eastern Lhasa terrane provide significant Received 29 May 2015 information for comprehensive understanding of geodynamic processes of northward subduction of the Indian Received in revised form 18 October 2015 lithosphere and uplift of the Tibetan Plateau. A combined dataset of whole-rock major and trace elements, Accepted 3 November 2015 Sr–Nd–Pb isotopes, and in situ zircon U–Pb dating and Hf–O isotopic analyses are presented for the Yangying Available online 23 December 2015 potassic volcanic rocks (YPVR) in the eastern part of the Lhasa terrane, South Tibet. These volcanic rocks consist of trachytes, which are characterized by high K O(5.46–9.30 wt.%), SiO (61.34–68.62 wt.%) and Al O (15.06– Keywords: 2 2 2 3 – – Post-collisional potassic magmatism 17.36 wt.%), and relatively low MgO (0.47 2.80 wt.%) and FeOt (1.70 4.90 wt.%). Chondrite-normalized rare Zircon U–Pb dating earth elements (REE) patterns display clearly negative Eu anomalies.
    [Show full text]
  • Introduction to Himalayan Tectonics: a Modern Synthesis
    Downloaded from http://sp.lyellcollection.org/ at Kingston University on January 3, 2020 Introduction to Himalayan tectonics: a modern synthesis MICHAEL P. SEARLE1* & PETER J. TRELOAR2 1Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, UK 2School of the Natural and Built Environment, Kingston University, Penrhyn Road, Kingston-upon-Thames, Surrey KT1 2EE, UK MPS, 0000-0001-6904-6398 *Correspondence: [email protected] The Himalaya resulted from collision of the Indian widespread migmatization and mid-crustal melting plate with Asia and are well known as the highest, during the Oligocene–Mid-Miocene. The age of the youngest and one of the best studied continental col- abundant leucogranite sills and dykes along the top lision orogenic belts. They are frequently used as the of the GHS, beneath the STD, is concomitant with type example of a continental collision orogenic belt the sillimanite-grade metamorphic event. The GHS in studies of older Phanerozoic orogenic belts. The metamorphism is all part of one continuum of crustal beauty of the Himalaya is that, on a broad scale they thickening and shortening, increasing pressure and form a relatively simple orogenic belt. The major temperature following a standard clockwise Pressure- structural divisions, the Indus–(Yarlung Tsangpo) Temperature-Time (PTt) path. Decompression suture zone, the Tethyan Himalaya sedimentary melting peaked with widespread partial melting and units, Greater Himalaya Sequence (GHS) metamor- formation of migmatites and leucogranites along the phic rocks, the Lesser Himalaya fold-and-thrust highest peaks of the Himalaya. Structural mapping belt and the Sub-Himalaya Siwalik molasse basin and timing constraints suggest the large-scale are present along the entire 2000 km length of the southward extrusion of a partially melted layer of Himalaya (Figs 1 & 2).
    [Show full text]
  • Mid-Cretaceous Thick Carbonate Accumulation in Northern Lhasa (Tibet): Eustatic Vs
    Mid-Cretaceous thick carbonate accumulation in Northern Lhasa (Tibet): eustatic vs. tectonic control? Yiwei Xu1, Xiumian Hu1,†, Eduardo Garzanti2, Marcelle BouDagher-Fadel3, Gaoyuan Sun4, Wen Lai1, and Shijie Zhang5 1 State Key Laboratory of Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China 2 Department of Earth and Environmental Sciences, Università di Milano-Bicocca, Milano 20126, Italy 3 Department of Earth Sciences, University College London, Gower Street, London, WC1E 6BT, UK 4 College of Oceanography, Hohai University, Nanjing 210098, China 5 School of Tourism, Henan Normal University, Xinxiang 453007, China ABSTRACT INTRODUCTION Moreover, their thickness does not exceed a few hundreds of meters, because carbonate Widespread accumulation of thick car- The Lhasa terrane, lying between the In- production is hampered in orogenic settings bonates is not typical of orogenic settings. dus–Yarlung suture to the south and the Ban- where tectonic uplift and erosion produce During the mid-Cretaceous, near the Ban- gong suture to the north (Fig. 1A), is the latest abundant terrigenous detritus (Wilson, 1975; gong suture in the northern Lhasa terrane, microcontinent accreted to Asia before colli- Dorobek, 1995). However, in a few cases (e.g., the shallow-marine carbonates of the Lang- sion between the Indian and Asian continental the Papua–New Guinea foreland basin) car- shan Formation, reaching a thickness up to margins. The timing of collision between the bonate thickness may reach 1.2 km (Sinclair, ∼1 km, accumulated in an epicontinental Qiangtang and Lhasa terranes along the Ban- 1997). Finally, carbonates generally occur only seaway over a modern area of 132 × 103 km2, gong suture (Fig.
    [Show full text]
  • Himalaya - Southern-Tibet: the Typical Continent-Continent Collision Orogen
    237 Himalaya - Southern-Tibet: the typical continent-continent collision orogen When an oceanic plate is subducted beneath a continental lithosphere, an Andean mountain range develops on the edge of the continent. If the subducting plate also contains some continental lithosphere, plate convergence eventually brings both continents into juxtaposition. While the oceanic lithosphere is relatively dense and sinks into the asthenosphere, the greater sialic content of the continental lithosphere ascribes positive buoyancy in the asthenosphere, which hinders the continental lithosphere to be subducted any great distance. Consequently, a continental lithosphere arriving at a trench will confront the overriding continent. Rapid relative convergence is halted and crustal shortening forms a collision mountain range. The plane marking the locus of collision is a suture, which usually preserves slivers of the oceanic lithosphere that formerly separated the continents, known as ophiolites. The collision between the Indian subcontinent and what is now Tibet began in the Eocene. It involved and still involves north-south convergence throughout southern Tibet and the Himalayas. This youthful mountain area is the type example for studies of continental collision processes. The Himalayas Location The Himalayas form a nearly 3000 km long, 250-350 km wide range between India to the south and the huge Tibetan plateau, with a mean elevation of 5000 m, to the north. The Himalayan mountain belt has a relatively simple, arcuate, and cylindrical geometry over most of its length and terminates at both ends in nearly transverse syntaxes, i.e. areas where orogenic structures turn sharply about a vertical axis. Both syntaxes are named after the main peaks that tower above them, the Namche Barwa (7756 m) to the east and the Nanga Parbat (8138 m) to the west, in Pakistan.
    [Show full text]
  • Tectonic Evolution and High-Pressure Rock Exhumation in the Qiangtang Terrane, Central Tibet
    Solid Earth, 6, 457–473, 2015 www.solid-earth.net/6/457/2015/ doi:10.5194/se-6-457-2015 © Author(s) 2015. CC Attribution 3.0 License. Tectonic evolution and high-pressure rock exhumation in the Qiangtang terrane, central Tibet Z. Zhao1,2, P. D. Bons1, G. Wang2, A. Soesoo3, and Y. Liu4 1Department of Geosciences, Eberhard Karls University Tübingen, Wilhelmstrasse 56, 72074 Tübingen, Germany 2School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China 3Institute of Geology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia 4State Key Laboratory for Continental Tectonics and Dynamics, Institute of Geology, CAGS, Beijing 100037, China Correspondence to: Z. Zhao ([email protected]) Received: 8 January 2015 – Published in Solid Earth Discuss.: 23 January 2015 Revised: 30 March 2015 – Accepted: 8 April 2015 – Published: 30 April 2015 Abstract. Conflicting interpretations of the > 500 km long, 1 Introduction east–west-trending Qiangtang metamorphic belt have led to very different and contradicting models for the Permo– Triassic tectonic evolution of central Tibet. We define two The Tibetan plateau is an amalgamation of terranes that were metamorphic events, one that only affected pre-Ordovician accreted to the southern margin of Eurasia during Phanero- basement rocks and one subduction-related Triassic high- zoic times (Yin and Harrison, 2000). From north to south, pressure metamorphism event. Detailed mapping and struc- these terranes are the Qilian Shan, Qaidam, Songpan–Ganzi tural analysis allowed us to define three main units that flysch complex, Qiangtang and Lhasa terranes (Fig. 1a). Ter- were juxtaposed due to collision of the north and south rane boundaries are defined by widely scattered belts of ophi- Qiangtang terranes after closure of the Ordovician–Triassic olitic fragments and mélanges with high-pressure rocks (Zhu ocean that separated them.
    [Show full text]
  • Late Paleozoic and Mesozoic Evolution of the Lhasa Terrane in the Xainza MARK Area of Southern Tibet
    Tectonophysics 721 (2017) 415–434 Contents lists available at ScienceDirect Tectonophysics journal homepage: www.elsevier.com/locate/tecto Late Paleozoic and Mesozoic evolution of the Lhasa Terrane in the Xainza MARK area of southern Tibet ⁎ Suoya Fana,b, , Lin Dinga, Michael A. Murphyb, Wei Yaoa, An Yinc a Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China b Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX 77204, USA c Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA 90095-1567, USA ARTICLE INFO ABSTRACT Keywords: Models for the Mesozoic growth of the Tibetan plateau describe closure of the Bangong Ocean resulting in Lhasa terrane accretion of the Lhasa terrane to the Qiangtang terrane along the Bangong-Nuijiang suture zone (BNSZ). Shortening However, a more complex history is suggested by studies of ophiolitic melanges south of the BNSZ “within” the Foreland basin Lhasa terrane. One such mélange belt is the Shiquanhe-Namu Co mélange zone (SNMZ) that is coincident with Suture zone the Geren Co-Namu Co thrust (GNT). To better understand the structure, age, and provenance of rocks exposed Provenance along the SNMZ we conducted geologic mapping, sandstone petrography, and U-Pb zircon geochronology of Geochronology rocks straddling the SNMZ. The GNT is north-directed and places Paleozoic strata against the Yongzhu ophiolite and Cretaceous strata along strike. A gabbro in the Yongzhu ophiolite yielded a U-Pb zircon age of 153 Ma. Detrital zircon age data from Permian rocks in the hanging wall suggests that the Lhasa terrane has affinity with the Himalaya and Qiangtang, rather than northwest Australia.
    [Show full text]
  • Lhasa Terrane in Southern Tibet Came from Australia
    Lhasa terrane in southern Tibet came from Australia Di-Cheng Zhu1*, Zhi-Dan Zhao1, Yaoling Niu1,2,3, Yildirim Dilek4, and Xuan-Xue Mo1 1State Key Laboratory of Geological Processes and Mineral Resources, and School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China 2School of Earth Sciences, Lanzhou University, Lanzhou 730000, China 3Department of Earth Sciences, Durham University, Durham DH1 3LE, UK 4Department of Geology, Miami University, Oxford, Ohio 45056, USA ABSTRACT REGIONAL GEOLOGY AND DETRITAL The U-Pb age and Hf isotope data on detrital zircons from Paleozoic metasedimentary rocks ZIRCON ANALYSES ε in the Lhasa terrane (Tibet) defi ne a distinctive age population of ca. 1170 Ma with Hf(t) values The Lhasa terrane is one of the three large identical to the coeval detrital zircons from Western Australia, but those from the western east-west−trending tectonic belts in the Tibetan Qiangtang and Tethyan Himalaya terranes defi ne an age population of ca. 950 Ma with a similar Plateau. It is located between the Qiangtang ε Hf(t) range. The ca. 1170 Ma detrital zircons in the Lhasa terrane were most likely derived from and Tethyan Himalayan terranes, bounded by the Albany-Fraser belt in southwest Australia, whereas the ca. 950 Ma detrital zircons from both the Bangong-Nujiang suture zone to the north the western Qiangtang and Tethyan Himalaya terranes might have been sourced from the High and the Indus–Yarlung Zangbo suture zone to Himalaya to the south. Such detrital zircon connections enable us to propose that the Lhasa the south, respectively (Fig.
    [Show full text]
  • A Middle Eocene Lowland Humid Subtropical “Shangri-La” Ecosystem in Central Tibet
    A Middle Eocene lowland humid subtropical “Shangri-La” ecosystem in central Tibet Tao Sua,b,c,1, Robert A. Spicera,d, Fei-Xiang Wue,f, Alexander Farnsworthg, Jian Huanga,b, Cédric Del Rioa, Tao Dengc,e,f, Lin Dingh,i, Wei-Yu-Dong Denga,c, Yong-Jiang Huangj, Alice Hughesk, Lin-Bo Jiaj, Jian-Hua Jinl, Shu-Feng Lia,b, Shui-Qing Liangm, Jia Liua,b, Xiao-Yan Liun, Sarah Sherlockd, Teresa Spicera, Gaurav Srivastavao, He Tanga,c, Paul Valdesg, Teng-Xiang Wanga,c, Mike Widdowsonp, Meng-Xiao Wua,c, Yao-Wu Xinga,b, Cong-Li Xua, Jian Yangq, Cong Zhangr, Shi-Tao Zhangs, Xin-Wen Zhanga,c, Fan Zhaoa, and Zhe-Kun Zhoua,b,j,1 aCAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China; bCenter of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla 666303, China; cUniversity of Chinese Academy of Sciences, 100049 Beijing, China; dSchool of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, MK7 6AA, United Kingdom; eKey Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 100044 Beijing, China; fCenter for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, 100101 Beijing, China; gSchool of Geographical Sciences and Cabot Institute, University of Bristol, Bristol, BS8 1TH, United Kingdom; hCAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, 100101 Beijing, China; iKey Laboratory of
    [Show full text]
  • Variation of Moho Depth Across Bangong-Nujiang Suture in Central Tibet—Results from Deep Seismic Reflection Data
    International Journal of Geosciences, 2015, 6, 821-830 Published Online August 2015 in SciRes. http://www.scirp.org/journal/ijg http://dx.doi.org/10.4236/ijg.2015.68066 Variation of Moho Depth across Bangong-Nujiang Suture in Central Tibet—Results from Deep Seismic Reflection Data Zhanwu Lu1,2,3*, Rui Gao1,2,3, Hongqiang Li1,2,3, Wenhui Li1,2,3, Xiaosong Xiong1,2,3 1Key Laboratory of Earthprobe and Geodynamics, Ministry of Land and Resources of PRC, Beijing, China 2State Key Laboratory of Continental Tectonics and Dynamics, Beijing, China 3Institute of Geology, Chinese Academy of Geological Science, Beijing, China Email: *[email protected] Received 10 June 2015; accepted 4 August 2015; published 7 August 2015 Copyright © 2015 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract There is a long-term dispute at Moho depth across the Bangong-Nujiang suture (BNS). Due to the complicated and changeable seismic geological condition, it is not easy to acquire images of the reflective Moho in central Tibet. In the support of the SinoProbe project, a series of deep seismic reflection profiles were conducted to image Moho structure across the BNS and the Qiangtang ter- rane. These profiles extend from the northern Lhasa terrane to the Qiangtang terrane crossing the BNS. Both shot gathers and migration data show clear Moho images beneath the BNS. The Moho depth varies from 75.1 km (~24 s TWT) beneath the northmost Lhasa terrane to 68.9 km (~22 s TWT) beneath southmost Qiangtang terrane, and rises smoothly to 62.6 km (~20 s TWT ) at ~28 km north of the BNS beneath the Qiangtang terrane.
    [Show full text]