The uplift of Qing—Zang (Qinghai—Tibet) plateau was the most important event in the late Cenozoic, which deeply influenced the environments of the World, especially those of China. Since the uplift is so important a...The uplift of Qing—Zang (Qinghai—Tibet) plateau was the most important event in the late Cenozoic, which deeply influenced the environments of the World, especially those of China. Since the uplift is so important and complex that it has been become the research focus of earth science. Nevertheless, the initial time and evolution process of the uplift is still controversial.1\ The initial time of the uplift\;Qing\|Zang plateau is a union geological\|geomorphic unit, which is composed of several geological\|structural units. Each geological\|structural unit has itself exchange history of sea\|continent (basin\|mountain); the exchange time of the different parts differs. Therefore, the initial time of some part of the plateau is not the uplift time of the whole plateau. The plateau is the highland with high height above sea level, little relief of the top, large area and steep boundary. The plateau plane is the paleo\|peneplain, which was formed by the uplift of the plateau after the peneplanation. Therefore, the initial time of the uplift should be counted from the time that the peneplain had been formed.展开更多
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 ...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 intensity of tectonic move- ments influencing the crossing of climatic thresholds, leading to terrace development, need to be studied further.展开更多
Planation surfaces includes peneplain, pediment and etchplain, which differ from each other in formation and distribution. The double leveling surfaces theory offered by Budel can be used to explain the landforms in l...Planation surfaces includes peneplain, pediment and etchplain, which differ from each other in formation and distribution. The double leveling surfaces theory offered by Budel can be used to explain the landforms in limestone areas. According to Budel, that the residue is the upper layer of a planation surface is very important in studying the formation展开更多
Traditional theories of geographical cycle and pediplain cannot describe correctly the development of planation surfaces in karst regions. Authors, therefore, put forward conception of karst planation and karst planat...Traditional theories of geographical cycle and pediplain cannot describe correctly the development of planation surfaces in karst regions. Authors, therefore, put forward conception of karst planation and karst planation surface, suggesting that karst planation is another type of planation process characterized by chemical erosion and transformation. To identify the distinction between evolution features of normal landforms and those of karst landforms developed in the South China, authors suggest karst planation surfaces under similar environmental conditions may reach a lower altitude and gradient ratio, in contrast with normal landform areas. This may be applied to researching on Tibetan Plateau uplift.展开更多
文摘The uplift of Qing—Zang (Qinghai—Tibet) plateau was the most important event in the late Cenozoic, which deeply influenced the environments of the World, especially those of China. Since the uplift is so important and complex that it has been become the research focus of earth science. Nevertheless, the initial time and evolution process of the uplift is still controversial.1\ The initial time of the uplift\;Qing\|Zang plateau is a union geological\|geomorphic unit, which is composed of several geological\|structural units. Each geological\|structural unit has itself exchange history of sea\|continent (basin\|mountain); the exchange time of the different parts differs. Therefore, the initial time of some part of the plateau is not the uplift time of the whole plateau. The plateau is the highland with high height above sea level, little relief of the top, large area and steep boundary. The plateau plane is the paleo\|peneplain, which was formed by the uplift of the plateau after the peneplanation. Therefore, the initial time of the uplift should be counted from the time that the peneplain had been formed.
基金Foundation: National Natural Science Foundation of China, No.41522101 National Key Research and Development Program, No.2016YFA0600500 Dutch-Chinese Exchange Program
文摘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 intensity of tectonic move- ments influencing the crossing of climatic thresholds, leading to terrace development, need to be studied further.
文摘Planation surfaces includes peneplain, pediment and etchplain, which differ from each other in formation and distribution. The double leveling surfaces theory offered by Budel can be used to explain the landforms in limestone areas. According to Budel, that the residue is the upper layer of a planation surface is very important in studying the formation
基金This work was supported by the State Key Project on Fundamental Research Planning (Grant No. G1998040800) CAS Pandeng Projects (Grant No. kz951 -A 1 -204 and kz95T-06).
文摘Traditional theories of geographical cycle and pediplain cannot describe correctly the development of planation surfaces in karst regions. Authors, therefore, put forward conception of karst planation and karst planation surface, suggesting that karst planation is another type of planation process characterized by chemical erosion and transformation. To identify the distinction between evolution features of normal landforms and those of karst landforms developed in the South China, authors suggest karst planation surfaces under similar environmental conditions may reach a lower altitude and gradient ratio, in contrast with normal landform areas. This may be applied to researching on Tibetan Plateau uplift.