The Hoh Xil basin, with an area of 101000km\+2 and an average elevation of over 5000m, is a largest Tertiary sedimentary basin in the hinterland of the Tibetan plateau. It is situated in the western part of the Baya H...The Hoh Xil basin, with an area of 101000km\+2 and an average elevation of over 5000m, is a largest Tertiary sedimentary basin in the hinterland of the Tibetan plateau. It is situated in the western part of the Baya Har terrain (BT) and the northern part of the Qiangtang terrain (QT), and covers the Jinsha River Suture Zone (JRSZ), one of the five continental suture zones on the Tibetan plateau. Strong deformation and crustal shortening of about 40% at the Fenghuoshan area (Coward,et al.1990) or 42.8% at the Wudaoliang—Fenghuoshan area (Wang,et al.1999) happened at the northern Tibet before the Neogene. Therefore, sediments deposited the Hoh Xil basin may contain significant information of crustal shortening and early uplift of the Tibetan plateau. However, anterior researchers met a same painful problem to date the sedimentary sequences in the basin. By using a few fossils, they assessed doubt ages for main strata in the Hoh Xil basin, as the Paleogene / Eocene (Yi,et al.1990) or the Cretaceous (BGMRQ 1991; Zhang & Zheng 1994), since other datable materials like volcanic rocks are absent. Therefore, the precise stratigraphic dating becomes a precondition of more scientific research in the northern Tibet.展开更多
文摘The Hoh Xil basin, with an area of 101000km\+2 and an average elevation of over 5000m, is a largest Tertiary sedimentary basin in the hinterland of the Tibetan plateau. It is situated in the western part of the Baya Har terrain (BT) and the northern part of the Qiangtang terrain (QT), and covers the Jinsha River Suture Zone (JRSZ), one of the five continental suture zones on the Tibetan plateau. Strong deformation and crustal shortening of about 40% at the Fenghuoshan area (Coward,et al.1990) or 42.8% at the Wudaoliang—Fenghuoshan area (Wang,et al.1999) happened at the northern Tibet before the Neogene. Therefore, sediments deposited the Hoh Xil basin may contain significant information of crustal shortening and early uplift of the Tibetan plateau. However, anterior researchers met a same painful problem to date the sedimentary sequences in the basin. By using a few fossils, they assessed doubt ages for main strata in the Hoh Xil basin, as the Paleogene / Eocene (Yi,et al.1990) or the Cretaceous (BGMRQ 1991; Zhang & Zheng 1994), since other datable materials like volcanic rocks are absent. Therefore, the precise stratigraphic dating becomes a precondition of more scientific research in the northern Tibet.
