川滇地块东部老鹰山的构造地貌特征及其揭示的地块隆升和旋转运动  

Tectonic and geomorphological characteristics of Laoyingshan in the eastern Sichuan-Yunnan block:Insights into the uplift and rotation of the blocks

作　　者：徐琴如 董有浦 谢志鹏[1] 任洋洋 李江涛[1] 曹登驰 苏小龙 XU Qinru;DONG Youpu;XIE Zhipeng;REN Yangyang;LI Jiangtao;CAO Dengchi;SU Xiaolong(Faculty of Land and Resource Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China)

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：《地质力学学报》2024年第4期535-546,共12页Journal of Geomechanics

基　　金：云南省基础研究专项−面上项目(202401AT070327)。

摘　　要：印−欧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,同时引起川滇菱形地块的侧向逃逸与旋转,目前针对川滇菱形地块中部和西部地区的旋转量已进行了大量古地磁研究,但对其东部地区的旋转研究相对缺少。由于河流地貌对地块的旋转量十分敏感,因此,研究利用30 m分辨率的数字高程模型(DEM)提取了川滇菱形地块东部老鹰山地区的22个流域盆地,通过分析其局部地形起伏比、河流纵剖面、河流陡峭指数以及流域方位角4个地貌参数来确定老鹰山地区的地块旋转量和隆升量。研究结果显示:老鹰山地区自晚中新世以来,隆升量约为358 m,隆升趋势为北高南低;河流陡峭指数值整体分布趋势由北向南逐渐降低,高值区主要分布在老鹰山地区北部,低值区主要分布在研究区老鹰山顶部以及老鹰山地区南部;同时根据流域方位角结果表明老鹰山地区旋转量为逆时针旋转15°左右。研究表明自晚中新世以来,川滇地块内元谋断裂以西受走滑断裂影响较小,主要为顺时针旋转;元谋断裂以东受走滑断裂等强烈的左行走滑影响,发生了逆时针旋转并伴随着差异隆升。[Objective]Since the collision and compression of the Indo-European continental plates,the Qinghai-Tibetan Plateau has experienced uplift and intra-land deformationSince the collision and compression of the Indo-European continental plates,the Qinghai-Tibetan Plateau has experienced uplift and intra-land deformation.Similarly,the Sichuan-Yunnan block underwent lateral escape and rotationSince the collision and compression of the Indo-European continental plates,the Qinghai-Tibetan Plateau has experienced uplift and intra-land deformation.Similarly,the Sichuan-Yunnan block underwent lateral escape and rotation.Although extensive paleomagnetic studies have been conducted on the rotation of the central and western parts of the Sichuan-Yunnan rhombic block,less attention has been paid to the rotation of its eastern partSince the collision and compression of the Indo-European continental plates,the Qinghai-Tibetan Plateau has experienced uplift and intra-land deformation.Similarly,the Sichuan-Yunnan block underwent lateral escape and rotation.Although extensive paleomagnetic studies have been conducted on the rotation of the central and western parts of the Sichuan-Yunnan rhombic block,less attention has been paid to the rotation of its eastern part.This study employs fluvial geomorphology,which is highly sensitive to mass rotation,to investigate the rotation and uplift in the Laoyingshan region,situated in the eastern part of the Sichuan-Yunnan block.[Methods]A 30 m resolution digital elevation model(DEM)was used to identify and analyze 22 basins in the study area.Four geomorphological parameters were examined:local topographic relief ratio,longitudinal profile,normalized steepness index,and basin azimuth.[Results](1)According to regional topographic relief,the low-relief area in the Laoyingshan region is mainly located near the Sijia River and the Baizai River on the western side,whereas the high-relief area is mainly found near the Dabai River and the Gongshan River on the eastern side of the Laoyingshan.The relief

关 键 词：地块旋转 地块隆升 构造地貌学 小江断裂 川滇地块东部 

分 类 号：P931.2[天文地球—自然地理学]