川滇地块东部建水北部的构造地貌特征及其揭示的地块隆升和旋转运动  

The tectonic and geomorphological characteristics of northern Jianshui in the eastern Sichuan-Dian Block,implications for uplift and rotational movement

作　　者：朱毅林 董有浦 徐琴如 宁雨涛 苏小龙 曹登驰 任洋洋 ZHU Yilin;DONG Youpu;XU Qinru;NING Yutao;SU Xiaolong;CAO Dengchi;REN Yangyang(Kunming University of Science and Technology,Kunming 650093,Yunnan)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093

出　　处：《第四纪研究》2024年第6期1662-1673,共12页Quaternary Sciences

基　　金：云南省企业基础研究应用基础研究联合专项项目(批准号:202101BC070001-003);云南省基础研究专项-面上项目(批准号:202401AT070327)共同资助。

摘　　要：印-欧亚大陆板块的碰撞与挤压造成了青藏高原的隆升和陆内变形,形成了一系列大型走滑断裂带,并导致了川滇地块的侧向逃逸与旋转。因此,川滇地块是研究青藏高原东南缘新生代构造隆升和旋转的理想地区。前人对川滇地块中部和西部地区的旋转量进行了大量古地磁研究,而对该地区东部的研究主要基于现代观测,关于该地区历史时期隆升和旋转的研究相对较少。因此,研究川滇地块东部的隆升和旋转将有助于深入了解整个青藏高原东南缘的变形特征。本研究利用30 m分辨率的数字高程模型(DEM),提取了建水北部的10条河流的流域,通过分析其局部地形起伏度、河流纵剖面、河流陡峭指数以及流域方位角4个地貌参数,重建了该地区的地块隆升和旋转。地形起伏度分析结果显示,自晚中新世以来,建水北部地区产生了275 m的地形起伏,地形起伏变量整体呈东部高西部低、北部高南部低的分布趋势;河流纵剖面结果显示,该地区平均隆升量约78 m,且整体差异不大;河流陡峭指数值整体偏小,相对高值区分布在研究区东南部;流域方位角结果表明建水北部地区发生了约19.8°的逆时针旋转。分析表明,自晚中新世以来,川滇地块内元谋断裂以西地区受走滑断裂影响较小,主要表现为顺时针旋转;而元谋断裂以东地区受走滑断裂强烈影响,发生了逆时针旋转并伴随着差异隆升。The collision and compression between the Indian-Eurasian continental blocks have uplifted and deformed the Tibetan Plateau,forming large-scale strike-slip fault zones and causing lateral escape and rotation of the Sichuan-Yunnan block.Consequently,the Sichuan-Yunnan block is an ideal area to study tectonic uplift and rotation at the southeastern margin of the Tibetan Plateau.Previous studies on rotation in the central and western regions of the Sichuan-Yunnan block have predominantly relied on paleomagnetic research,while studies in the eastern region have primarily used modern observations.Research on historical uplift and rotation in this area is relatively limited.Therefore,investigating uplift and rotation in the eastern part of the Sichuan-Yunnan block will enhance understanding of deformation characteristics across the southeastern margin of the Tibetan Plateau.This paper chooses Jianshui County in the east of Sichuan-Yunnan block as the research area.Jianshui County(23°12'~24°10'N,102°33'~103°11'E)is located in the south of Yunnan Province.It belongs to Honghe Hani and Yi Autonomous Prefecture of Yunnan Province.The area is sandwiched between the secondary faults of the eastern branch of the Xiaojiang fault and the Heiyi-Xiaoshuijing fault and the Xiaoguan-Lihaozhai fault are developed on the NE sides,respectively.In this study,a 30-meter resolution digital elevation model(DEM)was employed to delineate drainage basins of 10 rivers in northern Jianshui.Analysis of four geomorphic parameters—topographical relief,longitudinal profile,channel steepness index,and basin azimuth—was conducted to reconstruct uplift and rotation in this area.Topographical relief analysis indicates a 275-meter uplift since the Late Miocene,with higher elevation trending eastward and northward.Longitudinal profile analysis shows an average uplift of approximately 78 meters,exhibiting minimal variation.Channel steepness index values are generally low,with higher values in the southeast.Basin azimuth analysis reveals a 19.8°c

关 键 词：地块旋转 地块隆升 构造地貌学 川滇地块东部 

分 类 号：P546[天文地球—构造地质学] P931.1[天文地球—地质学]