EROSION AND UPLIFT OF TIBETAN PLATEAU
青藏高原的剥蚀与构造抬升*

We have measured average erosion rates, using cosmogenic nuclide ^10Be and ^26Al dating technique, in northwest and the northern part of Tibet. The average erosion rates are 12m/Ma and 15m/Ma, respectively. Cosmogenic nuclide dating and fission-track thermochronology are techniques which can confine landform denudation rate in different time scales. The former confines erosion rates in a time interval of hundreds thousands years and the latter confines erosion rates in a time scale of some million years. Comparison of erosion rates obtained via the two methods we could find that the average erosion rate in northern and interior Tibetan Plateau decreased from over 100m/Ma in Miocene to 10m/Ma in the last hundreds thousand years. We attribute the decrease of erosion rates to reduced tectonic activities in the last hundreds thousands years in the Tibetan Plateau. Therefore the major uplift of Tibetan Plateau should have occurred before Late Quaternary.