The Cretaceous suturing process of the eastern Bangong-Nujiang Ocean, Basu area

The Bangong-Nujiang Ocean played an important role in the formation and uplift of the Tibetan Plateau prior to the Cenozoic India-Eurasia collision. However, there are still uncertainties about the subduction polarity and the timing of the Lhasa-Qiangtang collision. We conducted sandstone petrology and detrital zircon U-Pb-Hf isotopic analyses on Cretaceous Wada mélange, trench-fill strata and Duoni Formation in the Basu area of the eastern Bangong-Nujiang Ocean. Our results indicate that the Wada mélange and trench-fill strata (ca. 114Ma) developed during the northward subduction of the Bangong-Nujiang Ocean, and the subsequent Duoni Formation (ca. 113Ma) in the Lhasa terrane represent a remnant of peripheral foreland basin and therefore marks the initial Lhasa-Qiangtang collision.