Cenozoic Kinematic Evolution of the Northern Tibetan Plateau: Implication for the Tectonic Setting of Deep Brines Mineralization in the Southwestern Qaidam Basin

Abstract

Abstract The Cenozoic kinematic evolution of the northern Tibetan Plateau resulted in the growth of the Eastern Kunlun Range, Qaidam Basin, and Qilian Shan. The widely developed lithium‐brine hosted within the southwestern Qaidam Basin make the basin one of the most promising regions for brines mineralization across the plateau. Better understanding the Cenozoic deformation and basin‐range interaction of the southwestern Qaidam Basin are significant in deciphering the kinematic evolution of the northern Tibetan Plateau and model of lithium brines formation. Despite decades of studies, the initiation timing, kinematics, and pattern of Cenozoic deformation across the northern Tibetan Plateau, and its role in impacting the Cenozoic deep‐brine mineralization, are poorly constrained. In this study, we conducted field observations, apatite fission track analysis, and synthesis of published data in the southwestern Qaidam Basin to improve our understanding of the Cenozoic intra‐plate deformation. Our results indicate that the northern Tibetan Plateau has experienced multi‐stage out‐of‐sequence development, which involved Late Cretaceous extension, Eocene‐Oligocene contraction and growth strata development, and accelerated mid‐Miocene exhumation. The southwestern Qaidam Basin experienced lacustrine deposition at the Oligocene time, and switched to a fluvial environment since Miocene. With this kinematic and sedimentary model, we provide new constraints on tectonic setting of Cenozoic deep‐brine mineralization in the southwestern Qaidam Basin. Synchronous range growth surrounding the basin formed an internally drained sedimentary environment since the Oligocene, which was optimal for deep‐brine mineralization associated with Oligocene‐Miocene volcanism in the Hoh Xil Basin to the south.