The time of the formation and destruction of the Meso-Cenozoic peneplanation surface in East Sayan |
| |
| Institution: | 1. Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences, ul. Lermontova 128, Irkutsk, 664033, Russia;2. Laboratoire Géosciences Rennes, UMR CNRS 6118, Université Rennes 1, Rennes, France;3. LGCA, ISTerre, Université de Savoie, Le Bourget-du-Lac, France;4. Laboratoire Géosciences Montpellier, UMR CNRS 5243, Université Montpellier 2, Montpellier, France;1. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, Moscow, 109017, Russia;2. A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, ul. Favorskogo 1a, Irkutsk, 664033, Russia;1. Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences, ul. Lermontova 128, Irkutsk, 664033, Russia;2. Institute of Geology, Chinese Academy of Geological Sciences, Baiwanzhuang Road 26, Beijing, 100037, China;3. Beijing SHRIMP Center, Chinese Academy of Geological Sciences, Beijing, 100037, China;4. A.P. Karpinsky Russian Geological Research Institute, Srednii pr. 74, St. Petersburg, 199106, Russia;1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;2. School of Geology and Petroleum Engineering, Mongolian University of Science and Technology, Ulaanbaatar 120646, Mongolia;1. Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;2. HKU Shenzhen Institute of Research and Innovation, Shenzhen, China;3. Xinjiang Research Center for Mineral Resources, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;4. Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia;5. The Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia;6. State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China |
| |
| Abstract: | The history of the peneplain in East Sayan was studied using apatite fission-track analysis (AFTA). This method is suitable for determining the formation time of the erosional surface and estimating its denudation rate. The largest known relic of the peneplanation surface in this area is the Oka Plateau, separated from the Kropotkin Ridge by the Oka–Zhombolok fault. The AFTA shows that the peneplain on the Oka Plateau formed in the Late Jurassic–Early Cretaceous. This peneplain is much younger than the erosional surfaces that persist today in the Tien Shan, Gobi Altai, and Mongolian Altai (Early Jurassic). However, it is older than the peneplain on the Chulyshman Plateau, Altai (Late Cretaceous), suggesting asynchronous formation of the ancient peneplain in Central Asia. The similar exhumation histories of samples from the Oka Plateau and Kropotkin Ridge indicate that these morphotectonic structures developed from Jurassic to late Miocene as a single block, which underwent continuous slow denudation at an average rate of 0.0175 mm/yr. Active tectonic processes in the Late Miocene caused the destruction of the peneplanation surface and its partial uplifting to different altitudes. The rate of Pliocene–Quaternary vertical movements along the Oka–Zhombolok fault is roughly estimated at 0.046–0.080 mm/yr, which is several times higher than the denudation rate in this area. During the Pliocene–Quaternary, the Oka Plateau has not undergone any significant morphologic changes owing to its intermediate position between the summit plain and datum surface of East Sayan and to its partial shielding by basaltic lavas. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
