The Qaidam Basin is. a tectonically controlled depression at 2700 m altitude on the northern margin of the Tibet Plateau. A succession of Neogene clastic sediments indicates lake depocentre migration from NW to SE. To...The Qaidam Basin is. a tectonically controlled depression at 2700 m altitude on the northern margin of the Tibet Plateau. A succession of Neogene clastic sediments indicates lake depocentre migration from NW to SE. Towards late Pliocene, evaporative conditions developed with formation of gypsum, halite, celestite, mirabilite and bloedite. Continued deformation through Pleistocene developed a series of NW- SE trending domes and troughs. This setting continued to exert a controlling influence on basin and brine evolution and the progressive development of sulfate to chloride brines as, dry conditions intensified in late Pleistocene, at the end of which, extensive flat floors were formed in Dalangtan, Qarhan and other playas.The, model, which was set up based on the synthetic analyses, divides the fluctuating palaeoclimate since 750ka,B. P. into 11 warm and humid stages and 10 dry and cold stages. The water of the lakes evaporated during the dry-cold periods and were freshened during the warm-humid展开更多
The Qaidam Basin is a large intermontane depression. It has been in existence since the Jurassic. The mean elevation of the basin floor is 2800 m. It covers an area of 120,000 km^2 with a catchment area of about 250,0...The Qaidam Basin is a large intermontane depression. It has been in existence since the Jurassic. The mean elevation of the basin floor is 2800 m. It covers an area of 120,000 km^2 with a catchment area of about 250,000 km^2. By the end of the Pliocene, great changes had taken place. Some of the lakes were evolving to the evaporite formation stage. The deposition continued through the Pliocene and the late Pleistocene to produce a sequence 2000—3000 m thick, and the total thickness of halite sequence is more than 1000 m. The Qaidam Basin contains some of the richest salt resources, the sediments deposited on展开更多
文摘The Qaidam Basin is. a tectonically controlled depression at 2700 m altitude on the northern margin of the Tibet Plateau. A succession of Neogene clastic sediments indicates lake depocentre migration from NW to SE. Towards late Pliocene, evaporative conditions developed with formation of gypsum, halite, celestite, mirabilite and bloedite. Continued deformation through Pleistocene developed a series of NW- SE trending domes and troughs. This setting continued to exert a controlling influence on basin and brine evolution and the progressive development of sulfate to chloride brines as, dry conditions intensified in late Pleistocene, at the end of which, extensive flat floors were formed in Dalangtan, Qarhan and other playas.The, model, which was set up based on the synthetic analyses, divides the fluctuating palaeoclimate since 750ka,B. P. into 11 warm and humid stages and 10 dry and cold stages. The water of the lakes evaporated during the dry-cold periods and were freshened during the warm-humid
文摘The Qaidam Basin is a large intermontane depression. It has been in existence since the Jurassic. The mean elevation of the basin floor is 2800 m. It covers an area of 120,000 km^2 with a catchment area of about 250,000 km^2. By the end of the Pliocene, great changes had taken place. Some of the lakes were evolving to the evaporite formation stage. The deposition continued through the Pliocene and the late Pleistocene to produce a sequence 2000—3000 m thick, and the total thickness of halite sequence is more than 1000 m. The Qaidam Basin contains some of the richest salt resources, the sediments deposited on
