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We disagree the basic aspects regarding the evolution of the Bangong–Nujiang Meso-Tethyan Ocean (BNMTO) proposed by Li et al. (2019) (Earth-Science Reviews 198, doi: 10.1016/j.earscirev.2019.102907). Extensive Mid-Cretaceous ophiolite fragments and marine sedimentary rocks along the suture zone, along with Mid-Cretaceous magmatic arc (as late as 94 Ma) in the southern Qiangtang margin, indicates the BNMTO did not close until the Late Cretaceous, consistent with paleomagnetic data. Mid-Cretaceous OIB-type mafic rocks, covered by radiolarian-bearing cherts and being cold-emplaced ophiolitic fragments, together with Mid-Cretaceous magmatism of distinct arc affinity along the southern Qiangtang margin, indicate no magmatic evidence for divergent double subduction of the BNMTO. We also stress oceanic plateaus could have played a key role in the subduction evolution of the BNMTO. [ABSTRACT FROM AUTHOR]

The Majiari ophiolite lies in the western Bangong-Nujiang Suture Zone, which separates the Qiangtang and Lhasa blocks in central Tibet. The ophiolite consists of peridotite, gabbro/diabase and basalt. Zircon U-Pb dating yielded an age of 170.5 ± 1.7 Ma for the gabbro, whereas 40 Ar/ 39 Ar dating of plagioclase from the same gabbro yielded ages of 108.4 ± 2.6 Ma (plateau age) and 112 ± 2 Ma (isochron age), indicating that the ophiolite was formed during the Middle Jurassic and was probably emplaced during the Early Cretaceous. Zircons from the gabbro have ε Hf (t) values ranging from +6.9 to +10.6 and f (Lu/Hf) values ranging from −0.92 to −0.98. Mafic lavas plot in the tholeiitic basalt field but are depleted in Nb, Ta and Ti and enriched in Rb, Ba and Th in the N-MORB-normalized trace element spider diagram. These lavas have whole-rock ε Nd ( t ) values of +5.9 to +6.6, suggesting that they were derived from a depleted mantle source, which was probably modified by subducted materials. The Majiari ophiolite probably formed in a typical back-arc basin above a supra-subduction zone (SSZ) mantle wedge. Intra-oceanic subduction occurred during the Middle Jurassic and collision of the Lhasa and South Qiangtang terranes likely occurred in the Early Cretaceous. Thus, closure of the Bangong–Nujiang Tethys Ocean likely occurred before the Early Cretaceous. [ABSTRACT FROM AUTHOR]