Petrogenesis of Middle–Late Triassic volcanic rocks from the Gangdese belt, southern Lhasa terrane: Implications for early subduction of Neo-Tethyan oceanic lithosphere

Wang, Chao; Ding, Lin; Zhang, Li Yun; Kapp, Paul; Pullen, Alex; Yue, Yahui

doi:10.1016/j.lithos.2016.07.021

Cited by 184 publications

(119 citation statements)

References 92 publications

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“…More importantly, most of the latest Triassic to middle Jurassic rocks are calc‐alkaline, and show positive zircon ε Hf (t) values (Dong et al, ; Guo et al, ; Ji et al, ; Kang et al, ; Meng, Dong, Cong, Xu, & Cao, ; Tang et al, ; H. F. Zhang et al, ). Most recently, C. Wang et al () point out that the northward subduction of Neotethyan oceanic lithosphere beneath the Lhasa terrane commenced from Middle Triassic based on analyses on the ca 237–212 Ma Changguo volcanic rocks in the southernmost part of the Lhasa terrane.…”

Section: Discussionmentioning

confidence: 99%

Early Jurassic intra‐oceanic arc system of the Neotethys Ocean: Constraints from andesites in the Gangdese magmatic belt, south Tibet

Meert

et al. 2017

Island Arc

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The Gangdese magmatic belt is located in the southern margin of the Lhasa terrane, south Tibet. Here zircon U–Pb ages and Hf isotopic data, as well as whole‐rock geochemistry and Sr–Nd isotopes on andesites from the Bima Formation with a view to evaluating the history of the Gangdese magmatism and the evolution of the Neotethys Ocean. Zircon U–Pb dating yields an age of ca 170 Ma from six samples, representing the eruptive time of these volcanic rocks. Zircon Hf isotopes show highly positive εHf(t) values of +13 to +16 with a mean of +15.2. Whole‐rock geochemical and Sr–Nd isotopic results suggest that the magma source of these andesites was controlled by partial melting of a depleted mantle source with addition of continental‐derived sediments, similar to those in the southern arcs of the Lesser Antilles arc belt. In combination with published data, the volcanic rocks of the Bima Formation are proposed to have been generated in an intra‐oceanic arc system, closely associated with northward subduction of the Neotethyan oceanic lithosphere.

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Section: Discussionmentioning

confidence: 99%

Early Jurassic intra‐oceanic arc system of the Neotethys Ocean: Constraints from andesites in the Gangdese magmatic belt, south Tibet

Meert

et al. 2017

Island Arc

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“…The dating of detrital zircons from the Xigaze fore‐arc basin also verified that it is an important stage of Gangdese arc magmatism (Wu et al, ). Wang et al () presented zircon U‐Pb dating, 237–211 Ma, of six samples of basaltic and andesitic volcanic rocks from the southern Gangdese belt, which is earlier than the time span of 205–152 Ma classified by Ji et al ().…”

Section: Geological Settingsmentioning

confidence: 98%

“…Exposure of the 205–152 Ma granitoids is quite limited, but there are some synchronous volcanic rocks and successions found in the southern Lhasa terrane (Zhu et al, , ). The magmatism in this stage is related to the northward subduction of the Neo‐Tethyan oceanic slab beneath the Lhasa terrane (Chu et al, ; Ji et al, ; Wang et al, ; Zhu et al, ). Chu et al () published the first in situ U‐Pb age 188 Ma of the igneous zircons from Gangdese granites and identified this previously unknown stage of magmatism in the Gangdese belt.…”

Section: Geological Settingsmentioning

confidence: 99%

Aeromagnetic Anomalies in Central Yarlung‐Zangbo Suture Zone (Southern Tibet) and Their Geological Origins

Wang

Yao

2020

JGR Solid Earth

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Two subparallel east‐west trending linear aeromagnetic anomalies are observed along the central Yarlung‐Zangbo suture zone in southern Tibet. The Yarlung‐Zangbo suture zone represents the boundary of the Eurasian and Indian plates and records the subduction of the Neo‐Tethyan oceanic slab and subsequent continental collision. The two magnetic lineaments are spatially associated with the Gangdese batholith and Xigaze ophiolites, which are separated by the Xigaze fore‐arc basin that is filled with nonmagnetic sedimentary sequences. The Mesozoic‐Cenozoic Gangdese batholith is characterized by widespread I‐type granitoids. The Xigaze ophiolites are dominated by serpentinized mantle peridotites. To investigate the geological origins and deep structures of the magnetic sources of the two magnetic lineaments, a 3‐D inversion of aeromagnetic anomaly data was undertaken. By analyzing our inversion model and further magnetic modeling, it is proposed that the Gangdese batholith has a magmatic root with higher magnetization than the exposed granitoids, indicating that the deeper part of the Gangdese batholith may contain more mafic constituents than the shallow part. The subsurface part of the Xigaze ophiolites resembles a thin slab dipping to the south, implying that the deep‐seated Xigaze ophiolites are also serpentinized and retain complete structure.

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“…To discuss the genesis and tectonic setting of Early Mesozoic magmatic rocks in the southern margin of the Lhasa terrane, most geochemical and geochronological studies on the Early Mesozoic magmatic rocks in the southern margin of the Lhasa terrane have focused on felsic rocks (M. F. Chu et al, ; Guo et al, ; Ji et al, ; Lang et al, ; S. W. Ma, Meng, et al, ; Meng, Dong, et al, ; Qu, Hou, Zaw, & Li, ; Tafti, Mortensen, Lang, Rebagliati, & Oliver, ; J. X. Tang et al, ; C. Wang et al, ; Wen et al, ; Z. M. Yang, Hou, Xia, Song, & Li, ; H. F. Zhang, Xu, et al, ). However, only a few mafic rocks of the Early Mesozoic have been identified along the southern Lhasa terrane (Kang et al, ; Meng, Xu, et al, ; J. S. Qiu, Wang, Zhao, & Yu, ; C. Wang et al, ; B. Xu et al, ). The lack of mafic rock data limits our understanding of the petrogenesis and tectonic setting of these Early Mesozoic magmatic rocks.…”

Section: Introductionmentioning

confidence: 99%

“…(b) Tectonic framework of the Lhasa terrane (modified from D. C. Zhu et al, ). (c) Diagram showing the distribution of magmatic rocks in the Lhasa terrane (modified from Wang et al, ). (d) Geologic map of the Xiongcun district (modified from Oliver, ).…”

Section: Introductionmentioning

confidence: 99%

Composition and age of Jurassic diabase dikes in the Xiongcun porphyry copper–gold district, southern margin of the Lhasa terrane, Tibet, China: Petrogenesis and tectonic setting

et al. 2017

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Diabase dikes are extensively distributed in the Xiongcun porphyry copper–gold district in the southern margin of the Lhasa terrane. Here, we report zircon U–Pb ages determined by laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) along with Hf isotopic, whole‐rock elemental, and Sr–Nd–Pb isotopic data for these diabase dikes. Zircons from one of the Xiongcun diabase dikes yielded an emplacement age of 165.3 ± 1.0 Ma. The Xiongcun diabase dikes display subalkaline features and tholeiite compositions. They are enriched in large‐ion lithophile elements (e.g., Rb, Ba, and K) and light rare earth elements and are depleted in high‐field‐strength elements (e.g., Nb, Ta, and Ti). The Xiongcun diabase dikes exhibit relatively low ratios of (87Sr/86Sr)i (0.70386–0.70501), (206Pb/204Pb)i (18.15–18.40), (207Pb/204P)i (15.52–15.57), and (208Pb/204Pb)i (38.06–39.46) and relatively high values of εNd(t) (5.85–6.92) and εHf(t) (+12.58 to +14.03). Combined with previous research results, these findings suggest that the Xiongcun diabase dikes and Early Mesozoic magmatic rocks in the southern margin of the Lhasa terrane formed in an active continental margin magmatic arc setting related to the northward subduction of the Neo‐Tethys oceanic slab; however, the possibility that the Xiongcun diabase dikes were formed in an intra‐oceanic arc setting cannot be excluded. Their parental magmas were formed by the partial melting of the depleted mantle source that was modified by fluids released from the Neo‐Tethys oceanic slab. The magmas experienced fractional crystallization of olivine and clinopyroxene and underwent limited crustal contamination during magma emplacement. The ~165 Ma Xiongcun diabase dikes, which probably originated under an extensional stress condition in a magmatic arc setting, correspond to the timing of Middle Jurassic subduction‐related porphyry copper mineralization (161–172 Ma) in the southern margin of the Lhasa terrane, likely suggesting that this episode of mineralization occurred during a period of changing stress from compression to extension.

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Petrogenesis of Middle–Late Triassic volcanic rocks from the Gangdese belt, southern Lhasa terrane: Implications for early subduction of Neo-Tethyan oceanic lithosphere

Cited by 184 publications

References 92 publications

Early Jurassic intra‐oceanic arc system of the Neotethys Ocean: Constraints from andesites in the Gangdese magmatic belt, south Tibet

Early Jurassic intra‐oceanic arc system of the Neotethys Ocean: Constraints from andesites in the Gangdese magmatic belt, south Tibet

Aeromagnetic Anomalies in Central Yarlung‐Zangbo Suture Zone (Southern Tibet) and Their Geological Origins

Composition and age of Jurassic diabase dikes in the Xiongcun porphyry copper–gold district, southern margin of the Lhasa terrane, Tibet, China: Petrogenesis and tectonic setting

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