Comment on “Sedimentary and Tectonic Evolution of the Southern Qiangtang Basin: Implications for the Lhasa-Qiangtang Collision Timing” by A. Ma et al.

Abstract

Ma et al. (2017, https://doi.org/10.1002/2017JB014211) proposed that the Lhasa-Qiangtang collision commenced in late Bathonian time (~166 Ma), based on the observation of an angular unconformity that truncated the Bathonian Buqu Formation from the late Bathonian-early Callovian Biluoco Formation and the recognition of siliciclastic provenance switch from arc igneous source to uplifted orogenic source in the Biluoco-Qixiangco area of the southern Qiangtang basin. Unfortunately, however, extensive exposure of Late Jurassic-Middle Cretaceous ophiolite fragments and marine sedimentary rocks along the Bangong suture zone indicates that the Bangong Meso-Tethys Ocean did not close until the Late Cretaceous, which is consistent with a Late Jurassic-Middle Cretaceous magmatic arc in the southern Qiangtang terrane as well as paleomagnetic data. The late Bathonian orogenic event in the southern Qiantang area observed by Ma et al. (2017, https://doi.org/10.1002/2017JB014211) can be explained by subduction of oceanic highs on the Bangong Meso-Tethyan Ocean. Clearly, our submission is a significant clearance to Ma et al.'s work and the Tibetan Plateau geology and of timely significance in correctly understanding the evolution history of the Tibetan Plateau. Therefore, our paper possibly is of broad interest to our international colleagues.