Figure 5
(a) Regional correlation of channel profiles of the Dibang catchment with the Yarlung-Siang system. The prominent 3k knickpoints are observed in Dibang and Yarlung drainage system. Note the χ profile of tributary channel in syntaxial zone clearly show the lower Siang and Dibang are in equilibrium, whereas the upper Siang, Yarlung and Parlung are clearly the aggressor channels. The ~4 Ma paleo-base levels of 3k knickpoint of Dibang river matches with the base level of paleo-Yarlung graded channel profile. Note the paleo-base level advantage of Siang river might have facilitated the capture of Yarlung. (b) Probable paleo-course of the Yarlung river during early Mio-Pliocene. (c) The χ map and profile of the Yarlung-Siang and Dibang drainage system clearly show drainage reversal of Upper Siang/Paleo-Yarlung at the coincident drainage divide and the Yarlung remain very active in the Tsangpo gorge driving the gradation processes in the region. (d) Note the provenance contribution by older grains at Dibang mountain front in comparison to the Siang.
