Soft-sediment deformation structures from the Diexi paleo-dammed lakes in the upper reaches of the Minjiang River,east Tibet |
| |
| Authors: | Ping Wang Bin Zhang Weili Qiu Jiancun Wang |
| |
| Institution: | 1. ?stanbul Teknik Üniversitesi, Ayaza?a Yerle?kesi, Maden Fakültesi, Jeoloji Mühendisli?i, 34469 Maslak, Istanbul, Turkey;2. Munzur Üniversitesi, Aktuluk Yerle?kesi, Mühendislik Fakültesi, Jeoloji Müh. Bölümü, 62000 Tunceli, Turkey;1. School of Earth Sciences, East China University of Technology, Nanchang 330013, China;2. Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China;3. Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China;1. Institute of the Earth Crust SB RAS, Irkutsk, Russia;2. Institute of Petroleum-Gas Geology SB RAS, Novosibirsk, Russia;3. Shmidt Institute of Physics of the Earth RAS, Moscow, Russia;4. Kyrgyz-Russian Slavic University named after B. N. Yeltsin, Biskhek, Kyrgyzstan;5. State Research Institute “Center of Natural Studies”, Vilnius, Lithuania;6. Institute of Earthquake Prediction Theory and Mathematical Geophysics RAS, Moscow, Russia;7. Institute of Seismology NAS KR, Bishkek, Kyrgyzstan |
| |
| Abstract: | The north–south-trending upper reaches of the Minjiang River run along the Longmen Shan–Min Shan fault zone, a zone of abrupt topographic change along the eastern margin of the Tibetan Plateau. Multiple levels of well-preserved soft-sediment deformation structures (seismites) occur in sediments deposited in paleo-dammed lakes in the upper part of the Minjiang River Valley. These deformation structures include liquefied convolute deformation, water-escape structures, flame structures, pseudonodules, ball-and-pillow structures, sedimentary dykes, mud lenses, and large-scale folds. Several kilometers from the barrier bar of the Diexi paleo-dammed lakes, seven deformed structural layers were identified at different heights in late Quaternary stratigraphic sequences near Shawan Village, Maoxian County. Analyses of the deformation structures, landforms, and the structural environment indicate that these deformation structures were caused by earthquakes, slumps, and landslides.OSL (optical stimulated luminescence) and 14C dating of soft-sediment layers from the Shawan site indicate that intense earthquakes occurred during the period 25–20 ka B.P. Therefore, accurate geological dating of deformed features in dammed lake deposits in high mountains and canyons enables the record of moderate- to large-magnitude earthquakes to be extended to the late Pleistocene–Holocene upon the eastern Tibetan Plateau. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
