Post-subdution evolution of the Northern Lhasa Terrane, Tibet: Constraints from geochemical anomalies, chronology and petrogeochemistry

Abstract

Bangong-Nujiang collisional zone (BNCZ) is an older one in Qinghai-Tibet Plateau and resulted in the famous Bangong-Nujiang metallogenic belt, which plays an important role in evaluating the formation and uplift mechanism of plateau. The northern and central Lhasa Terrane composed the southern part of the BNCZ. Since ore deposits can be used as markers of geodynamic evolution, the authors carried 1∶50000 stream sedimental geochemical exploration in the Xiongmei area in the Northern Lhasa Terrane to manifest the mineralization, and based on this mineralization with geochemical and chronological characteristics of related magmatic rocks to constrain their geodynamics and connection with the evolution of the Lhasa Terrane. The authors find Early Cretaceous magma mainly resulted in Cu, Mo mineralization, Late Cretaceous magma mainly resulted in Cu, Mo, and W mineralization in the studying area. The results suggest a southward subduction, slab rolling back and break-off, and thickened lithosphere delamination successively occurred within the Northern Lhasa Terrane.© 2022 China Geology Editorial Office.