Multiple sources of the Early Mesozoic Gouli batholith, Eastern Kunlun Orogenic Belt, northern Tibetan Plateau: Linking continental crustal growth with oceanic subduction

Abstract

Orogenic belts have been among the most important locations to investigate the growth of continental crust (CC). The Eastern Kunlun Orogenic Belt (EKOB), which contains widespread Permian-Triassic granitoids, is volumetrically comparable to the Cenozoic Gangdese magmatic belt in the Tibetan Plateau and is an ideal region to investigate the mechanism of the Paleozoic-Mesozoic CC growth in this region. The Gouli batholith at the eastern end of the EKOB consists of the synchronous Xiangride granodiorite, Asiha quartz diorite (ca. 242 Ma) and adamellite. The granodiorite and quartz diorite, both of which contain magmatic enclaves, show medium-high K, calc-alkalic and metaluminous signatures and have similar rare earth element and trace element patterns to those of bulk CC. Besides, the Xiangride granodiorite displays distinct adakitic signatures (average Sr/Y of 47). The Sr-Nd isotopic values for the different types of rocks are roughly similar ((87 Sr/ 86 Sr) i = 0.708167-0.713553, ε Nd (t) =-6.8 to-5.3), while Hf isotopes are distinguishable, with ε Hf (t) granodiorite = 0.3 to 5.1 and ε Hf (t) diorite =-1.6 to 0.7. These geochemical and petrographic signatures suggest that the granodiorite originated from the partial melting of subducting oceanic crust and terrigenous sediments, and the quartz diorite and enclaves formed via the mixing of slab-derived magma and enriched mantle-derived melt. Further comprehensive analyses of the spatial and temporal distribution of regional magmatic rocks, metamorphism and sedimentary facies reveal that the Gouli batholith and most of the Permian-Triassic granitoids in the EKOB formed during the subduction of the Paleo-Tethys Ocean instead of subsequent syn-collision setting. Thus, we contend that the Permian-Triassic CC growth of the EKOB occurred in a slab

Fluid Inclusions and S–Pb Isotopes of the Reshui Porphyry Mo Deposit in East Kunlun, Qinghai Province, China

“…This region experienced subduction and collisional orogeny from the Late Permian to the Early Triassic as the Buqingshan-A'nemaqen Ocean, part of the Paleo-Tethys Ocean, generated northward subduction, which triggered crust-mantle magmatic activity and led to the emplacement of a large number of arc magmatic rocks that are linearly distributed across the region [6,16]. The inferred EKOB tectonic evolution indicates that the Late Triassic granitoids that formed after subduction were related to collisional to post-collisional tectonic processes [4,14,18]. This tectonic movement was related to the formation of porphyry-skarn type Cu-Mo-Au deposits.…”

“…The East Kunlun Orogenic Belt (EKOB) is located along the northern margin of the Tibetan Plateau [1][2][3] and is one of the most important magmatic arcs and polymetallic metallogenic belts in China [4][5][6][7][8]. Many porphyry-skarn deposits have been discovered and explored in this area (e.g., the Kaerqueka Cu-Mo porphyry deposit, Hutouya Cu-Pb-Zn skarn deposit, and Galinge Fe skarn deposit [9][10][11][12][13]).…”

Anisian granodiorites and mafic microgranular enclaves in the eastern Kunlun Orogen, NW China: Insights into closure of the eastern Paleo–Tethys

“…However, the timing of closure of the A'nyemaqen Ocean remains contentious. Yin and Zhang () and Huang et al () suggested that the A'nyemaqen Ocean closed in the Late Permian, whereas others argued that the cessation of subduction occurred in the Early Triassic (Shao et al, ; Yang, Xu, Li, & Shi, ), Middle Triassic (J. J. Chen et al, ; Li et al, ; Liu et al, ; Pei et al, ; Xia et al, ; Xiong et al, ; Zhang, Ma, Xiong, & Liu, ), or even Late Triassic (Roger et al, ).…”

Geochronology and geochemistry of the Late Devonian–Early Carboniferous volcanic rocks in Aksu River area, western end of the East Kunlun Orogen

“…It is widely accepted that the EKO records the history of the Proto‐Tethys‐related and Paleo‐Tethys‐related orogenesis (Hu et al, ; H. F. Yin & Zhang, ). A multitude of studies over the past decades focused on the tectonic evolution of Tethys orogenic system (J. J. Chen et al, ; Jiang et al, ; B. Liu et al, ; Mo et al, ; Şengör, ; R. Xia et al, ; Xiong, Ma, Zhang, Liu, & Jiang, ; Xu et al, ; Xu, Yang, Li, & Yao, ; H. F. Yin & Zhang, ). The timing of Proto‐Tethys Ocean closure remains controversial in the EKO: (a) Mo et al () considered that the Proto‐Tethys‐related Ocean closed in the Late Ordovician based on the Ar‐Ar ages of gabbro in the Tumuleke.…”

“…A multitude of studies over the past decades focused on the tectonic evolution of Tethys orogenic system (J. J. Chen et al, 2017;Jiang et al, 1992;B. Liu et al, 2012;Mo et al, 2007;Şengör, 1984;Xiong, Ma, Zhang, Liu, & Jiang, 2014;Xu et al, 2007;Xu, Yang, Li, & Yao, 2006;H.…”