Normal Faulting, basin development, and paleoelevation in south Tibet and the evolution of the Tibetan Plateau


The Tibetan-Himalayan orogen is the result of the ongoing plate convergence  between India and Eurasia since the Early Cenozoic. At a late stagemiddle-late  Miocene of this long-lasting history, the formation of several N-S trending  rift systems dissecting the Tibetan Plateau highlights significant changes in  the evolution of the orogen. The relation between the rifts in Tibet and the  uplift of the plateau is the key to a better understanding of the geological  evolution of the entire orogen. The joint Sino-German cooperation proposed  here will focus on this major scientific problem by investigating the  tectonic, sedimentological, and paleoelevation history of the Gyirong and  Nima-Dingri Rifts, . The lateralwhich extends over a distance of more than 300  km through the Lhasa terrane and into the Himalaya. The German group (this  proposal) will apply low-temperature thermochronology (i.e. fission track and  (U-Th)/He dating) on apatite and zircon along elevation profiles through  granitic intrusions, which are exposed in the footwalls of rift-bounding  faults. Thermokinematic modelling of the respective data will allow us to  quantify the onset of normal faulting and temporal variations in fault slip  along strike of the Gyirong graben and Nima-Dingri rift system. Our Chinese  partners will use sedimentological and magnetostratigraphic analyses to  reconstruct the evolution and the depositional environment of the  fault-controlled Gyirong graben basin. On this basis, they will use stable  isotope analysis of carbonate from paleosols, authigenic minerals, and fossils  to decipher how the paleoelevation of the Gyirong basin has changed through  time and how it is related to the activity of the basin-bounding faults. The  complementary approaches and results of our two working groups will lead to an  improved understanding of the causal relation between rift development, basin  formation, and paleoelevation on the Tibetan Plateau and their timing with  respect to past climate changes.

Principle Investigator:Ding lin

Project duration:2019.01-2021.12