Zircon U–Pb Geochronology and Petrogenesis of Early–Midlle Permian Arc–Related Volcanic Rocks in Central Jilin: Implications for the Tectonic Evolution of the Eastern Segment of Central Asian Orogenic Belt

Abstract

This paper presents age and geochemical data of a recently identified Late Paleozoic volcanic sequence in central Jilin Province, with aims to discuss the petrogenesis and to constrain the tectonic evolution of the Central Asian Orogenic Belt in this area. Firstly, the volcanic rocks have zircon U‐Pb ages of 290–270 Ma. Secondly, they are characterized by (a) ranging in composition from the low‐K tholeiite series to high‐K calc‐alkaline series; (b) enrichment in light rare earth elements and depletion of heavy rare earth elements, with negative Eu anomalies; and (c) negative Nb, Ta, and Ti anomalies. Finally, the volcanic rocks yield ∊Hf(t) values of +7.1 to +17. These data suggest that the central Jilin volcanic rocks were possibly derived from predominant partial melting of a depleted lithospheric mantle that might have been modified by subducted slab–derived fluids. Combined with previous studies, the Late Paleozoic–Early Mesozoic magmatism in Central Jilin can be divided into two stages: (a) a volcanic arc stage (290–270 Ma) represented by low‐K to high–K, tholeiite to calc–alkaline plutons and (b) a syn–collisional stage (260–240 Ma) represented by high‐K calc–alkaline I‐type granites. Furthermore, the timing and the tectonic setting of the above magmatic rocks show that the arc was probably produced by the northward subduction of the Paleo‐Asian Ocean and that the final closure of the Paleo‐Asian Ocean occurred prior to the Early Triassic.

The Late Triassic Molasse Deposits in Central Jilin Province, NE China: Constraints on the Paleo-Asian Ocean Closure

“…This region is adjacent to the Dunhua-Mishan Fault and the Songliao Basin to the east and west, respectively (Figure 1b). The CYS is composed mainly of Phanerozoic granitoids with a series of subduction-related tectonic mélanges, including the Kaiyuan, Xia ertai, Hulan, Seluohe, Qinglongcun, and Kaishantun tectonic mélanges [12,15,[21][22][23][25][26][27][28]31,35,47]. In addition, minor Paleozoic and Mesozoic sediments are also distributed in the "granite ocean" [39,[43][44][45][46][48][49][50].…”

“…This region is Dunhua-Mishan Fault and the Songliao Basin to the east and west, respe 1b). The CYS is composed mainly of Phanerozoic granitoids with a series related tectonic mélanges, including the Kaiyuan, Xia′ertai, Hulan, Seluohe and Kaishantun tectonic mélanges [12,15,[21][22][23][25][26][27][28]31,35,47]. In additio zoic and Mesozoic sediments are also distributed in the "granite ocean" [3 The study area is to the southeast of Jilin City, in central Jilin Prov According to the 1:200,000 geological map, this area mainly contains the Daheshen, the Upper Permian Fanjiatun and Yangjiagou, and the Triass dingzi formations [80] (Figure 2).…”

“…In one school of thought, the final closure occurred prior to the Permian, mainly including before the Late Devonian and between the Late Devonian [54][55][56] and Early Carboniferous [57][58][59]. In an alternative view, the closing of the PAO occurred during the Permian-Triassic, which can be reclassified as during the late Early Permian [60,61], during the Middle-Late Permian [62][63][64][65], during the Late Permian [4,34,48,66], during the Late Permian-Early Triassic [3,10,11,21,33,35,40,41,50,[67][68][69][70], during the Late Permian-Middle Triassic [5,22,25,26,28,32,42,71,72], and during the Middle-Late Triassic [20,24,37,49,73]. Therefore, substantial controversy remains regarding the closure time of the PAO along the CYS.…”

Final‐stage Southward Subduction of the Eastern Paleo‐Asian Ocean: Evidence from the Middle Permian Mafic Intrusions in the Northern Margin of the North China Craton

“…A consensus has been reached that the eastern Paleo-Asian Ocean experienced bidirectional subduction model, with the Solonker suture zone marking its final closure and termination of subduction-accretion activity (Xiao et al, 2003;Eizenhöfer et al, 2014Eizenhöfer et al, , 2015Yu et al, 2014;Guo et al, 2016;Shi et al, 2020). The occurrence of bidirectional subduction was supported by the distribution of Paleozoic subduction-accretion complexes and magmatic arcs of similar age on both sides of the Solonker suture zone (Xiao et al, 2003;Eizenhöfer et al, 2014Eizenhöfer et al, , 2015Yu et al, 2014;Guo et al, 2016;Song et al, 2018;Jing et al, 2020a, b), recent research based on the 3-D numerical modeling of the Molucca Sea region, however suggests bidirectional subduction only accessible for a limit oceanic basin (Zhang et al, 2017).…”