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The Zanda basin is located in the southwest of the Tibetan Plateau. There developed a suite of Tertiary-Quaternary sedimentary sequences to be called the Zanda Formation. It is composed of four members: A, B, C and D. Of them A, B and C are three cyclothems related to the periodic tectonic movements. They have a similar sedimentary sequence: upward from conglomerates through sandstone to mudstones. Grain sizes and sedimentary of these rocks are described. Penedeposi-tional and postdepositional defomations are also described. The provenance and nature of the basin are discussed from grain size, thickness and sedimentary structures as well as heavy mineral assemblage and rare earth elements. This basin is a tectonic compressional lows rather than a fault basin.
The Zanda basin is located in the southwest of the Tibetan Plateau. There developed a suite of Tertiary-Quaternary sedimentary sequences to be called the Zanda Formation. It is composed of four members: A, B, C and D. Of them A, B and C are three cyclothems related to the periodic tectonic movements. They have a similar sedimentary sequence. upward from conglomerates through sandstone to mudstones. Grain sizes and sedimentary of these rocks are described. Penedeposi-tional and postdepositional defomations are also described. The provenance and nature of the basin are discussed from grain size, thickness and sedimentary structures as well as heavy mineral assemblage and rare earth elements. This basin is a tectonic compressional lows rather than a fault basin.