Climatic and tectonic controls on the fluvial morphology of the Northeastern Tibetan Plateau （China）  

作　　者：WANG Xianyan Jef VANDENBERGHE LU Huayu Ronald VAN BALEN 

机构地区：[1]School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210023, China [2]Department of Earth Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands

出　　处：《Journal of Geographical Sciences》2017年第11期1325-1340,共16页地理学报（英文版）

基　　金：Foundation： National Natural Science Foundation of China, No.41522101; National Key Research and Development Program, No.2016YFA0600500; Dutch-Chinese Exchange Program

摘　　要：The geomorphological evolution of the Northeastern Tibetan Plateau （NETP） could provide valuable information for reconstructing the tectonic movements of the region. And the considerable uplift and climatic changes at here, provide an opportunity for studying the im- pact of tectonic and monsoon climate on fluvial morphological development and sedimentary architecture of fluvial deposits. The development of peneplain-like surface and related land- scape transition from basin filling to incision indicate an intense uplift event with morphologi- cal significance at around 10-17 Ma in the NETP. After that, incision into the peneplain was not continuous but a staircase of terraces, developed as a result of climatic influences. In spite of the generally persisting uplift of the whole region, the neighbouring tectonic blocks had different uplift rates, leading to a complicated fluvial response with accumulation terraces alternating with erosion terraces at a small spatial and temporal scale. The change in fluvial activity as a response to climatic impact is reflected in the general sedimentary sequence on the terraces from high-energy （braided） channel deposits （at full glacial） to lower-energy de- posits of small channels （towards the end of the glacial）, mostly separated by a rather sharp boundary from overlying flood-Ioams （at the glacial-interglacial transition） and overall soil formation （interglacial）. Pronounced incision took place at the subsequent warm-cold transi- tions. In addition, it is hypothesized that in some strongly uplifted blocks energy thresholds could be crossed to allow terrace formation as a response to small climatic fluctuations （10^3-10^4 year timescale）. Although studies of morpho-tectonic and geomorphological evolu- tion of the NETP, improve understanding on the impacts of tectonic motions and monsoonal climate on fluvial processes, a number of aspects, such as the distribution and correlation of peneplain and the related morphological features, the extent and inThe geomorphological evolution of the Northeastern Tibetan Plateau （NETP） could provide valuable information for reconstructing the tectonic movements of the region. And the considerable uplift and climatic changes at here, provide an opportunity for studying the im- pact of tectonic and monsoon climate on fluvial morphological development and sedimentary architecture of fluvial deposits. The development of peneplain-like surface and related land- scape transition from basin filling to incision indicate an intense uplift event with morphologi- cal significance at around 10-17 Ma in the NETP. After that, incision into the peneplain was not continuous but a staircase of terraces, developed as a result of climatic influences. In spite of the generally persisting uplift of the whole region, the neighbouring tectonic blocks had different uplift rates, leading to a complicated fluvial response with accumulation terraces alternating with erosion terraces at a small spatial and temporal scale. The change in fluvial activity as a response to climatic impact is reflected in the general sedimentary sequence on the terraces from high-energy （braided） channel deposits （at full glacial） to lower-energy de- posits of small channels （towards the end of the glacial）, mostly separated by a rather sharp boundary from overlying flood-Ioams （at the glacial-interglacial transition） and overall soil formation （interglacial）. Pronounced incision took place at the subsequent warm-cold transi- tions. In addition, it is hypothesized that in some strongly uplifted blocks energy thresholds could be crossed to allow terrace formation as a response to small climatic fluctuations （10^3-10^4 year timescale）. Although studies of morpho-tectonic and geomorphological evolu- tion of the NETP, improve understanding on the impacts of tectonic motions and monsoonal climate on fluvial processes, a number of aspects, such as the distribution and correlation of peneplain and the related morphological features, the extent and in

关 键 词：PENEPLAIN Miocene uplift fluvial terraces fluvial deposit climatic impact tectonic impact Northeastern Tibetan Plateau 

分 类 号：P542[天文地球—构造地质学] S812.1[天文地球—地质学]