地貌形态指数反映的青藏高原东北部宛川河流域新构造活动

发布时间：2018-01-07 00:41

本文关键词：地貌形态指数反映的青藏高原东北部宛川河流域新构造活动　出处：《地理学报》2016年03期 　论文类型：期刊论文

【摘要】：宛川河为黄河的一级支流,位于青藏高原东北部的兰州盆地东部。该区域历史时期曾发生多次6级以上地震。以DEM数据为基础,通过河流水系分析和地貌形态指数的计算,讨论了区域新构造活动特征。山前曲折度指数(SMF)在宛川河北为1.03~1.18,在兴隆山北前缘为1.83~2.88;河谷宽高比指数(VF)在宛川河北部为0.36~2.34,在南部的兴隆山为0.55~13。SMF与VF值的大小和分布特征表明研究区新构造活动活跃,且宛川河以北(前人推测有断层存在)新构造活动的活跃程度更高。流域盆地非对称性指数(AF)在宛川河北部东南端的异常揭示存在掀斜断块和褶皱运动;结合裂点分布和沟谷错断等地貌特征,发现宛川河北正断裂的东南端也存在西北—东南向走滑活动。
[Abstract]:The Wanchuan River is a first-order tributary of the Yellow River, located in the eastern part of Lanzhou Basin in the northeast of the Qinghai-Xizang Plateau. There have been many earthquakes of magnitude 6 or above in the historical period of the region, based on DEM data. Based on the analysis of river system and the calculation of geomorphology index, the characteristics of regional neotectonic activity are discussed. The forward zigzag index (SMF) in Wanchuan and Hebei is 1.03N1.18. In the north front of Xinglong Mountain, 1.83N 2.88; The VF index of the river valley is 0.36 ~ 2.34 in the north of Wanchuan River. The magnitude and distribution of the values of SMF and VF in the southern Xinglong Mountain are 0.55 and 13.The results indicate that the neotectonic activity is active in the study area. Moreover, the activity of neotectonic activity in the north of Wanchuan River (where faults are presumed to exist) is more active. The anomaly of the basin asymmetry index (AFF) in the southeastern end of Wanchuan River reveals the existence of tilting fault blocks and fold movement. According to the geomorphologic features of the fracture point distribution and gully fault, it is found that the northwest to southeast strike-slip activities also exist at the southeast end of the normal fault in Wanchuan.
【作者单位】：南京大学地理与海洋科学学院;南京大学地球科学与工程学院;
【基金】：国家自然科学基金项目(41522101)~~
【分类号】：P546
【正文快照】： 1引言利用现代地表形态可反演近地表的构造活动过程,如何从现有的地貌形态中提取相关的构造活动信息是构造地貌研究的核心问题。现代3S技术的发展尤其是高分辨率数字高程模型(DEM)的出现,为构造地貌的定量化研究提供了新的契机。地貌形态指数是对由内力作用形成地貌的外在形态

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