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The Minshan Mountain and adjacent region are the major continental escarpments along the eastern Tibetan Plateau. The Minjiang drainage basin is located within the plateau margin adjacent to the Sichuan Basin. Based on the analysis of the digital elevation model (DEM) acquired by the Shuttle Radar Topography Mission (SRTM), we know that the Minjiang drainage basin has distinct geomorphic characteristics. The regular increasing of local topographic relief from north to south is a result of the Quaternary sediment deposition within the plateau and the holistic uplift of the eastern margin of the Tibetan Plateau versus the Sichuan Basin. Results from DEM-determined Minjiang drainage sub-basins and channel profiles show that the tributaries on the opposite sides are asymmetric. Lower perimeter and area of drainage sub-basins, total channel length and bifurcation ratio within eastern flank along the Minjiang mainstream are the result of the Quaternary differential uplift of the Minshan Mountain region. Shorter stream lengths and lower bifurcation ratio might be the indications of the undergrowth and newborn features of these eastern streams, which are also representative for the eastern uplift of the Minshan Mountain. [ABSTRACT FROM AUTHOR]

The formation and evolution of the basement rocks in the Tibetan Plateau remain poorly constrained. Here we report petrology, geochemistry, and zircon U-Pb geochronology of orthogneisses, metamafic intrusions, andmetasedimentary rocks from the Amdo basement in central Tibet. The oldest Neoproterozoic (∼820 Ma) orthogneisses show chemical affinity to a volcanic arc setting. These rocks, together with the coeval arc-magmatic rocks, belong to an Andeantype setting traced from the Seychelles, Madagascar, western India, Lhasa, and South China blocks, following the Rodinia supercontinent assembly. The later early Paleozoic (∼500 Ma) bimodal intrusions in Amdo also show an affinity to arc-related igneous rocks and probably formed in an active continental margin associated with the subduction of the Proto-Tethys Ocean beneath the Gondwana supercontinent. In contrast to the adjacent Lhasa and Qiangtang terranes, the Amdo block experienced complex Neoproterozoic and early Paleozoic tectono-thermal events and coherent Jurassic (∼190 Ma) high-pressure granulite-facies metamorphism and associated magmatism, suggesting that the Amdo block was an isolated microcontinent in the Tethyan Ocean and underwent deep subduction before its collision with the Qiangtang or Lhasa terrane. [ABSTRACT FROM AUTHOR]