Late Paleozoic–Early Mesozoic granitoids in the Khangay–Khentey basin, Central Mongolia: Implication for the tectonic evolution of the Mongol–Okhotsk Ocean margin

Age, petrogenesis, and tectonic implications of the late Permian magmatic rocks in the Middle Gobi volcanoplutonic Belt, Mongolia

“…In addition, our study reports the first Triassic zircon age of ~250 Ma for the Mandalgovi pluton and the age of ~247 Ma for andesites of the Middle Gobi Belt. These ages are slightly older than the age of the subduction‐related granites in the Delgerkhaan area, Central Mongolia (220 Ma; Ganbat, Tsujimori, Miao, et al, 2021) and fit the age of the magmatic ‘flare‐up’ in the NE China (Liu et al, 2018). Our data, combined with previous published data (e.g., Zhao et al, 2017; Zhu et al, 2016) indicate two periods of active magmatism in the Middle Gobi belt and in NE Mongolia: late Paleozoic and early Mesozoic.…”

“…The small amount of peraluminous granites and the absence of detachment fault zones, gneiss domes, or metamorphic core‐complexes, usually associated with the post‐collisional granites makes a post‐collisional setting rather unlikely (Figure 3). The abundant subduction‐related magmatic complexes of the Central Mongolia–Erguna blocks formed during a period from the early Permian to the late Triassic (e.g., Ganbat, Tsujimori, Miao, et al, 2021; Zhao et al, 2017; Zhu et al, 2022). The primitive‐mantle normalized patterns of the Permian peraluminous granite and Sahalyn gol rhyolite show negative anomalies at Nb, Ta, and Ti (Figure 6), which are, in turn, typical of subduction‐related igneous rocks (e.g., Stern, 2002).…”

“…The magmatic spatial and temporal distribution show that the context is that Mongol–Okhotsk oceanic subduction was still taking place in the early Mesozoic (Figure 2). The late Paleozoic–Mesozoic magmatism in Central and NE Mongolia and NE China indicate that the southward subduction of the MOO crust beneath the Central Mongolia–Erguna microcontinent started in the Carboniferous (Figure 13) and the intensive subduction‐related magmatism occurred during the Permian–Triassic (Ganbat, Tsujimori, Miao, et al, 2021; Liu & Zhao, 2018; Tang et al, 2016; Zhao et al, 2017; Zhu et al, 2022). The new radiogenic ages obtained from the magmatic formations emplaced the southern margin of the Mongol–Okhotsk suture zone show no significant differences between the ages of the subduction‐related magmatic complexes extended from west to east along the Mongol–Okhotsk suture belt and therefore suggest that the MOO was suturing and closing coherently, i.e.…”

“…The study of these magmatic rocks is critical to reconstructing the tectonic evolution of the MOO. The Carboniferous–Permian magmatic belts at the southern side of the Mongol–Okhotsk suture belt (Figure 1) formed at an Andean‐type active continental margin (Figure 2; Tomurtogoo et al, 2005; Zhu et al, 2016; Zhao et al, 2017; Ganbat, Tsujimori, Miao, et al, 2021; Zhu et al, 2022).…”

“…The abundant subduction-related magmatic complexes of the Central Mongolia-Erguna blocks formed during a period from the early Permian to the late Triassic (e.g., Ganbat, Tsujimori, Miao, et al, 2021;Zhao et al, 2017;Zhu et al, 2022). The primitive-mantle normalized patterns of the Permian peraluminous granite and Sahalyn gol rhyolite show negative anomalies at Nb, Ta, and Ti (Figure 6), which are, in turn, typical of subduction-related igneous rocks (e.g., Stern, 2002).…”