Early Jurassic highly fractioned rhyolites and associated sedimentary rocks in southern Tibet: constraints on the early evolution of the Neo-Tethyan Ocean

Provenance of Late Triassic-Early Jurassic forearc basin in southern Tibet and its tectonic significance

“…The ages of the accretionary complex rocks in the southern Gangdese region from north to south, reflecting the continuous evolution of the northward subduction and southward accretion of the Zhikong-Sumdo Paleo-Tethys Ocean and Yarlung Zangbo Ocean in southern Tibet Wang et al, 2021b). In addition, the ages of the arc magmatic rocks in the southern Gangdese region decrease from north to south, while the corresponding zircon Hf isotope data also exhibit gradual depletion (Wang et al, 2019d). Although the opening age of the Yarlung Zangbo Ocean remains controversial, the opening age of the Yarlung Zangbo Ocean was during the Middle Triassic or earlier according to geologic records from the Yarlung Zangbo suture zone, including Middle Triassic radiolarians (Chen et al, 2019b) and Late Triassic ocean island rocks (Zhang et al, 2020).…”

“…9). The sedimentary debris that comprises the Jialapu Formation was derived from arc magmatism in the southern Gangdese region, while the provenance of the northern Gangdese region and the Zhikong-Sumdo accretionary complex were very limited (Yang, 2018;Wang et al, 2019d). The Jialapu Formation has similar provenance characteristics as the Liuqiong Formation, but the Liuqiong Formation contains almost no material from the northern Gangdese region and the Zhikong-Sumdo accretionary complex (Fig.…”