The Tibetan Plateau is a key region for the study of multi-spheres interactions. It is now characterized by a flat plateau surface with coupled basin and range relief, but when did this coupled basin and range structure begin to form?
Using analyses of U-Pb ages of zircons (a silicate mineral, ZrSiO4, chemically stable), paleocurrent directions, and sandstone composition preserved in detrital sediments with reliable chronology, also combined with the calculation of the contribution of a mixture of sources, a research team from the Institute of Earth Environment of the Chinese Academy of Sciences has reconstructed the provenance history of the Hoh Xil Basin, central-northern Tibetan Plateau, from the Late Cretaceous to the Early Miocene.
The researchers found that from the Late Cretaceous to the Early Miocene, the detrital zircon age spectra, paleocurrent directions and sandstone compositions of the Hoh Xil Basin did not apparently change, suggesting that its source did not change significantly during this period.
In addition, calculation of the source contribution indicates that the Late Cretaceous to the Early Miocene source area of the Hoh Xil Basin was mainly the Tanggula Mountains, which are located in the southern part of the present basin.
"This work suggests that the basin and range landform in the north-central Tibetan Plateau was formed at least as early as the Late Cretaceous, and that the collision of the Indian and Eurasian plates around 55 Ma may have made this geomorphic pattern even more remarkable," said Dr. LI Leyi, first author of the study.
"One of the distinctive features of the present-day Tibetan Plateau is the very flat plateau surface, so an important and interesting question should be when and how the previously distinctive basin and range relief was developed into the present flat plateau surface," said Dr. CHANG Hong, corresponding author of the study.
