李晓峰^1,,
王萍^1,,,
王慧颖¹,
童康益¹,
杨光²
1. 中国地震局地质研究所, 地震动力学国家重点实验室, 北京 100029
2. 广东省地质局第一地质大队, 广东 珠海 519000

基金项目: 中国地震行业科研经费专项项目（批准号：20150824）、国家自然科学基金项目（批准号：41772199）和中央级公益性科研院所基本科研业务专项项目（批准号：IGCEA1713）共同资助


详细信息

作者简介: 李晓峰, 男, 26岁, 硕士研究生, 构造地质学专业, E-mail:1205240611@qq.com

通讯作者: 王萍, E-mail:1355837527@qq.com

中图分类号: P931.2;P542

收稿日期:2017-06-02
修回日期:2017-10-19
刊出日期:2018-01-30

Differential tectonic uplift indicated by river geomorphic parameters at the Tsangpo River Gorge

Li Xiaofeng^1,,
Wang Ping^1,,,
Wang Huiying¹,
Tong Kangyi¹,
Yang Guang²
1. State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029
2. No.1 Geological Brigade of Guangdong Geological Bureau, Zhuhai 519000, Guangdong


More Information

Corresponding author: Wang Ping,E-mail:1355837527@qq.com

MSC: P931.2;P542

--> Received Date: 02 June 2017
Revised Date: 19 October 2017
Publish Date: 30 January 2018


摘要
摘要:雅鲁藏布江大拐弯地区的构造活动与河流侵蚀作用都十分强烈。利用数值地貌参数对构造抬升的敏感响应，本文对雅鲁藏布江中、下游流域的DEM数据进行了地貌参数的提取。通过对雅鲁藏布江及其支流的面积-高程积分和河流陡峭系数的分析，结合区域降雨量及岩性分布特征，探讨了不同区段地貌参数变化所蕴含的构造活动信息。研究发现雅鲁藏布江大拐弯地区的隆升活动具有明显的差异性，南迦巴瓦峰东部和北部的隆升活动强度高于西部，喜马拉雅构造结东端的隆升中心存在向北扩展、向东迁移的趋势，尤其以加拉至墨脱河段的岩石隆升最为强烈。加查裂点与南迦巴瓦裂点均位于隆升块体的西边界，横向构造隆升可能控制了裂点的形成和稳定。
关键词: 雅鲁藏布江大拐弯/
面积-高程积分/
河流陡峭系数/
差异隆升/
河流侵蚀

Abstract:The strong surface erosion in the middle and lower reaches of the Tsangpo River due to the river development, heavy rainfall and glacier movement is coupled with the intense tectonic activities in the Eastern Himalayan Syntaxes, which makes the Tsangpo River Gorge one of the strongest tectonic active areas. Some geomorphology parameters in the Tsangpo River could reflect the geomorphic evolution under the influence of tectonics because of their sensitivity to Cenozoic tectonic movements. The study area starts from Toxia (29°20'N, 90°E) in Renbu County to Bashika (28°06'N, 95°32'E). The watershed area is about 13.36×10⁴ km², which is account for about 52% of the Brahmaputra in China's drainage area. The strata can be divided into three stratigraphic zones by the Tsangpo suture zone under the control of regional structure. The north strata of the study area is the Gangdise-Tengchong formation, the middle is the Tsangpo formation and the south is the Himalaya formation.
By using digital geomorphology, precipitation and lithology, this article analyzes 30 m SRTM DEM data to extract the geomorphology parameters along the middle and downstream of Tsangpo River. Based on the erosion cycle and the stream-power river incision model, we extract 2698 subdivision of watershed in the study area to calculate the Hypsometric Integral values (HI), channel steepness index (k_sn)and other geomorphic parameters in order to discuss the spatial distribution of tectonic differential uplifting. The results show that the values of HI and k_sn in the northeast of the Namche Barwa massif are very high, which indicate that there is a differential tectonic uplift in the Eastern Himalayan Syntaxes controlled by collision of the Indian plate with the Eurasian plate. The tectonic activities of the north and eastern blocks are more intense than the western Namche Barwa syntaxis. In addition, the spatial distribution characteristics of geomorphology parameters show that the center of uplift block in Eastern Himalayan Syntaxes is intend to expand northward and move eastward, especially for Gala to Medog, where the tectonic activities are extremely obvious and intense. The Namche Barwa and Gala knickpoints extracted by DEM data are just located in the western boundary of uplift block, which can conclude that the conformation and stability of these knickpoints is the result of transverse tectonic uplift.
Key words:Tsangpo River Gorge/
Hypsometric Integral/
channel steepness index/
differential tectonic uplift/
river erosion



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