scholarly journals HP–UHP Metamorphic Belt in the East Kunlun Orogen: Final Closure of the Proto-Tethys Ocean and Formation of the Pan-North-China Continent

2018 ◽  
Vol 59 (11) ◽  
pp. 2043-2060 ◽  
Author(s):  
Shuguang Song ◽  
Hengzhe Bi ◽  
Shengsheng Qi ◽  
Liming Yang ◽  
Mark B Allen ◽  
...  
Keyword(s):  
North China ◽  
Metamorphic Belt ◽  
East Kunlun ◽  
Tethys Ocean ◽  
Final Closure

UHP metamorphism recorded by coesite-bearing metapelite in the East Kunlun Orogen (NW China)

2019 ◽  
Vol 157 (2) ◽  
pp. 160-172
Author(s):  
Hengzhe Bi ◽  
Shuguang Song ◽  
Liming Yang ◽  
Mark B. Allen ◽  
Shengsheng Qi ◽  
...  
Keyword(s):  
Central China ◽  
Ultrahigh Pressure ◽  
Metamorphic Belt ◽  
Clastic Rocks ◽  
Ultrahigh Pressure Metamorphism ◽  
East Kunlun ◽  
History Of ◽  
Tethys Ocean ◽  
Early Palaeozoic ◽  
Integrated Study

AbstractThe East Kunlun Orogen (EKO) is the NW part of the Central China Orogenic Belt, which records the evolutionary history of the Proto- and Palaeo-Tethys Oceans from the Cambrian to the Triassic. An Early Palaeozoic eclogite belt has been recognized in recent years, which extends discontinuously for ∼500 km as three eclogite-bearing terranes. In this study, we report an integrated study of zircon grains from mica-schists accompanying the eclogites, in terms of mineral inclusions, U–Pb age systematics and P–T conditions. The presence of coesite is identified, as inclusions within the metamorphic domain of zircons, which provides unambiguous evidence for subducted terrigenous clastic rocks of the Proto-Tethys Ocean exhumed from coesite-forming depths. U–Pb dating of the metamorphic zircons yields a concordia age of 426.5 ± 0.88 Ma, which is likely to be the time of ultrahigh-pressure metamorphism in the Kehete terrane. P–T calculations suggest that metapelite may have experienced a clockwise P–T path with peak P/T conditions of 685 ± 41 °C and >28 kbar, and equilibrated at 482–566 °C and 5.6–8.9 kbar during subsequent exhumation. The high-pressure – ultrahigh-pressure (HP-UHP) metamorphic belt within the EKO may have formed by collision between the Qaidam Block and the South Kunlun Block, as a consequence of the closure of the Proto-Tethys Ocean.

Geochemistry, zircon geochronology, and isotopic systematics of the Zhanbuzhale granites in the East Kunlun, Qinghai Province, northwestern China: implications for the tectonic setting

2020 ◽  
Vol 57 (2) ◽  
pp. 275-291
Author(s):  
Hao-Ran Li ◽  
Ye Qian ◽  
Feng-Yue Sun ◽  
Liang Li
Keyword(s):  
Tectonic Setting ◽  
Alkali Feldspar ◽  
Northwestern China ◽  
Geochemical Data ◽  
Calc Alkaline ◽  
Qinghai Province ◽  
East Kunlun ◽  
Initial Stage ◽  
High K ◽  
Tethys Ocean

The Zhanbuzhale region, in the Eastern Kunlun Orogen of northwestern China, is characterized by large volumes of Phanerozoic granitoid rocks and is an ideal region for investigating the tectonic evolution of the Paleo-Tethys system. However, the exact timing of the final closure of the Paleo-Tethys Ocean and initial continental collision remains controversial because of a lack of precise geochronological and detailed geochemical data. In this paper, we report new zircon U–Pb ages and mineralogical, petrographic, and geochemical data for samples of Middle Triassic granodiorite and alkali feldspar granite from the Zhanbuzhale region. The zircon U–Pb ages indicate that the granodiorite and alkali feldspar granite formed at 239 and 236 Ma, respectively. The granodiorites are high-K calc-alkaline, metaluminous, high Sr content, high Sr/Y ratios, low Y content, and show adakite-like affinities. The alkali feldspar granites display high SiO2, extremely low MgO, and low Zr+Nb+Ce+Y contents as well as low Fe2O3t/MgO ratios, showing metaluminous to peraluminous and high-K calc-alkaline features. Geochemical and petrological characteristics of the alkali feldspar granites suggest that they are highly fractionated I-type granites. The granodiorites and alkali feldspar granites have zircon εHf(t) values ranging from –2.26 to –0.18, and from –2.17 to +2.18, respectively. Together with regional geological data, we propose that the Triassic (approximately 239–236 Ma) granitoids were generated during the later stages of northward subduction of the Paleo-Tethys oceanic plate, and that the initial stage of collision between the East Kunlun and the Bayan Har–Songpan Ganzi terrane occurred at approximately 236–227 Ma.

scholarly journals Devonian to Triassic tectonic evolution and basin transition in the East Kunlun−Qaidam area, northern Tibetan Plateau: Constraints from stratigraphy and detrital zircon U−Pb geochronology

2021 ◽  
Author(s):  
Jiaopeng Sun ◽  
Yunpeng Dong ◽  
Licheng Ma ◽  
Shiyue Chen ◽  
Wan Jiang
Keyword(s):  
High Pressure ◽  
Tectonic Evolution ◽  
Late Triassic ◽  
The South ◽  
Northern Tibet ◽  
The North ◽  
Northern Tibetan Plateau ◽  
East Kunlun ◽  
North Qaidam ◽  
Tethys Ocean

The late Paleozoic to Triassic was an important interval for the East Kunlun−Qaidam area, northern Tibet, as it witnessed prolonged subduction of the South Kunlun Ocean, a major branch of the Paleo-Tethys Ocean whose closure led to the formation of Pangea. However, the geologic history of this stage is poorly constrained due to the paucity of tectonothermal signatures preserved during a magmatic lull. This article presents a set of new provenance data incorporating stratigraphic correlation, sandstone petrology, and zircon U−Pb dating to depict changes in provenance that record multiple stages of topographic and tectonic transition in the East Kunlun−Qaidam area over time in response to the evolution of the South Kunlun Ocean. Devonian intra-arc rifting is recorded by bimodal volcanism and rapid alluvial-lacustrine sedimentation in the North Qaidam Ultra High/High Pressure Belt, whose sources include the Olongbuluke Terrane and southern North Qaidam Ultra High/High Pressure Belt. Southward transgression submerged the East Kunlun−Qaidam area during the Carboniferous prior to the rapid uplift of the Kunlun arc, which changed the provenance during the Early Permian. This shift in provenance for the western Olongbuluke Terrane and thick carbonate deposition throughout the North Qaidam Ultra High/High Pressure Belt in the late Early Carboniferous indicate that the North Qaidam Ultra High/High Pressure Belt should have been inundated, terminating an ∼95 m.y. erosion history. The closure of the South Kunlun Ocean in the late Triassic generated a retroarc foreland along the Zongwulong Tectonic Belt, which is represented by the development of a deep-water, northward-tapering flysch deposystem that was supplied by the widely elevated Kunlun−Qaidam−Olongbuluke Terrane highland. This new scenario allows us to evaluate current models concerning the assembly of northern Tibet and the tectonic evolution of the Paleo-Tethys Ocean.

scholarly journals Geochronology and Geochemistry of Ore-Hosting Rhyolitic Tuff in the Kengdenongshe Polymetallic Deposit in the Eastern Segment of the East Kunlun Orogen

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 589 ◽  
Author(s):  
Liang ◽  
Xia ◽  
Shan ◽  
Ma ◽  
Zhao ◽  
...  
Keyword(s):  
Large Scale ◽  
Major And Trace Elements ◽  
Polymetallic Deposit ◽  
East Kunlun ◽  
Low Concentrations ◽  
Icp Ms ◽  
Eastern Segment ◽  
Rhyolitic Tuff ◽  
Tethys Ocean ◽  
Bayan Har

The Kengdenongshe Au–Ag–Pb–Zn polymetallic deposit, a newly discovered large-scale polymetallic deposit in the southeastern section of the East Kunlun Orogen (EKO), contains an Au resource of 40 t, Ag resource of 690 t and Pb–Zn resource of 10.5 × 105 t. The ore-bearing rocks are mainly composed of laminar barite and rhyolitic tuff. In this study, LA-ICP-MS zircon U–Pb dating and whole rock major and trace elements analyses have been conducted on the ore-bearing rhyolitic tuff. LA-ICP-MS zircon U–Pb dating data show that these rhyolitic tuffs were emplaced at ca. 243.3 ± 1.6 Ma. The samples show similar features to those of S-type granites, including high contents of SiO2 (76.4–82.6 wt. %) and Al2O3 (11.0–12.7 wt. %) and relatively low concentrations of Na2O (0.35–2.43 wt. %) and CaO (0.095–0.124 wt. %), with high A/CNK (molar [Al2O3/(CaO + Na2O + K2O)]) (1.72–2.03) and K2O/Na2O ratios (1.41–17.1). Further, they exhibit depletion in HFSEs (High Field Strength Elements) and enrichment in LREEs (Light Rare Earth Element) with negative Eu anomalies (Eu/Eu* = 0.51–0.64). These geochemical characteristics indicate that the Kengdenongcuo rhyolitic tuff originated from the fluid-absent melting of a plagioclase-poor, clay-rich metapelitic source and experienced minor fractional crystallization. In combination with arc-type magmatism and contemporaneous syn-collision granitoids in the region, the Kengdenongcuo tuff formed in a continental collision setting, implying that the Bayan Har–Songpan Ganzi Terrane collided with the East Kunlun Terrane and the Paleo-Tethys Ocean was closed at the period of ~243 Ma. The Kengdenongcuo polymetallic deposit formed at about the same time.

Precise Re-Os Dating of Molybdenite from the Northern Dabie Molybdenum Belt in Central China and its Geodynamic Implications

2012 ◽  
Vol 535-537 ◽  
pp. 1035-1038
Author(s):  
Jun Ping Li ◽  
Yong Feng Li ◽  
Ke Jia Xie
Keyword(s):  
North China ◽  
Central China ◽  
Metamorphic Belt ◽  
Dabie Orogen ◽  
East Central ◽  
The North ◽  
Metallogenic Belt ◽  
Vein Type ◽  
Granite Porphyries ◽  
Granitoid Intrusions

The Dabie orogen of east-central China marks the boundary between the North China and Yangtze Cratons, and is characterized by juxtaposition of the ~400Ma Tongbai metamorphic belt and the ~220Ma South Qinling-Dabie metamorphic belt. The Triassic collision between the North China and Yangtze Cratons which generated numerous granitoid intrusions such as the Shangcheng, Xingxian and Lingshan intrusions, and other small stocks, such as Tangjiaping, Dayinjian, Mushan and so on. Those shallow-emplaced granite porphyries are closely related to porphyry-skarn Mo and Mo-W deposites, forming the Dabie molybdenum metallogenic belt. Molybdenum deposits occur in the endo- and exocontact zones of the porphyry, include with three major types of Mo mineral systems, i.e., porphyry, less porphyry-skarn and vein-type. The ore-forming ages of the molybdenum deposits in Dabie area are mainly cluster 127.8±0.9~113.1±7.9Ma. The pulse is the product of the transformation of the tectonic regime from NS- to nearly EW-directions in East China.

A Tarim-North India connection in northern Gondwana: Constraints from provenance of early Paleozoic sedimentary rocks in the Altyn Tagh orogen, southeastern Tarim

2021 ◽  
Author(s):  
Qian Liu ◽  
Toshiaki Tsunogae ◽  
Guochun Zhao ◽  
Yigui Han ◽  
Jinlong Yao ◽  
...  
Keyword(s):  
South China ◽  
East Asian ◽  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Early Paleozoic ◽  
The North ◽  
Altyn Tagh ◽  
Tarim Craton ◽  
Tethys Ocean ◽  
Final Closure

<p>Amalgamation of northern Gondwana involves a wealth of present-day East Asian blocks (e.g., South China, North China, Alxa, Tarim, Indochina, Qiangtang, Sibumasu, Lhasa, etc.) due to consumption and closure of the Proto-Tethys Ocean. Locating the Tarim craton during assembly of northern Gondwana remains enigmatic, with different models separating Tarim from Gondwana by a paleoceanic domain throughout the Paleozoic, advocating a long-term Tarim-Australia linkage in the Neoproterozoic to the early Paleozoic, or suggesting a Tarim-Arabia connection in the early Paleozoic.</p><p>This study carried out field-based zircon U-Pb dating and Hf isotopic analyses for early Paleozoic sedimentary rocks in the Altyn Tagh orogen, southeastern Tarim. New dating results revealed that the early Paleozoic sedimentary rocks were deposited from ca. 494 to 449 Ma. Provenance tracing indicates the ca. 494-477 Ma sedimentary rocks were primarily sourced from the local Altyn Tagh orogen to the south of the North Altyn Ocean (one branch of the Proto-Tethys Ocean between southeastern Tarim and northern Gondwana). In contrast, the ca. 465-449 Ma sedimentary rocks have remarkably increasing ca. 840-780 Ma, 2.0-1.7 Ga, and 2.7-2.4 Ga detrital zircons, indicating an augmented supply of detritus from the Tarim craton to the north of the North Altyn Ocean. Such a significant provenance shift between ca. 477 and 465 Ma marks the timing of the final closure of the North Altyn Ocean. Combined with the timing of the final closure of other branches of the Proto-Tethys Ocean, the entire Proto-Tethys Ocean might have been progressively closed at ca. 500-420 Ma, resulting in the connection of most East Asian blocks with northern Gondwana. Based on detrital zircon U-Pb-Hf isotopic comparison, Tarim most likely shared a North Indian affinity with many East Asian blocks (such as North Qilian, North Qinling, South China, Indochina, South Qiangtang, etc.). This new finding argues against an Australian or Arabian affinity for the Tarim craton.</p><p>This work was financially supported by National Natural Science Foundation of China Projects (grants 41730213, 42072264, 41902229, 41972237, and 41888101), Hong Kong Research Grants Council General Research Fund (grant 17307918), and Grant-in-Aids for Scientific Research from Japan Society for the Promotion of Science (JSPS) to Prof. Toshiaki Tsunogae (No. 18H01300) and to Dr. Qian Liu (No. 19F19020). JSPS fellowship is also much appreciated.</p>

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