【作者】 谢冰晶；

【导师】 田明中；

【作者基本信息】 中国地质大学（北京） ， 第四纪地质学， 2014， 博士

【摘要】 滇西南大盈江流域位于喜马拉雅构造带向南东拐弯处，地处青藏高原与云贵高原的过渡地带，是解析云贵高原新生代隆升过程和新构造运动的关键区域。大盈江流域梁河、盈江盆地第四纪地层发育、地貌类型丰富、活动构造强烈、地震频发且震级较大，是研究第四纪沉积作用、地貌成因、新构造运动及活动构造的理想地区。但目前在该区开展的第四纪地质调查和相关研究工作不多，工作程度相对较低。本文在系统收集前人资料和详细野外地质调查工作基础上，通过深入研究和室内样品的分析测试，探讨了大盈江流域梁河、盈江盆地第四纪地层的建立和活动构造特征，取得了以下主要进展。采用地质调查和剖面测制，根据梁河、盈江两盆地第四纪沉积物类型、地貌特征、物质成分、时空分布、接触关系及产状特征，对本内广泛出露的第四纪沉积地层进行了详细划分，其中梁河盆地划分出4个统、3个组级、6个段级地层单位，盈江盆地划分出4个统、2个段级地层单位，初步搭建了梁河和盈江盆地第四纪地层层序。系统分析了梁河、盈江两个盆地的第四纪地貌特征与地貌演化。北部梁河盆地发育有七级阶地，其中第五、六级阶地为湖相沉积，其余为河流相特征；而南部盈江盆地发育为四级阶地，均为河流相沉积。梁河、盈江盆地均为部分继承性的第四纪断陷盆地，地貌演化过程可以分为谷地、湖盆、湖盆消亡和山间河流四个阶段，每一阶段的变化都紧密伴随有相应的构造运动。通过对大盈江活动断裂的几何学、运动学特征的研究和碳14与光释光年龄测试，将大盈江断裂分为南段盈江段和北段梁河段，其中盈江段为全新世北东向左旋走滑断层，其北段发育一条北北东向正断层与大盈江断裂相交；而梁河段为晚更新世北东向至近南北向弧形展布的正断层，兼有走滑特征，并在多处发育北西向正断层与梁河段形成共轭关系。通过计算拟合得到大盈江断裂第四纪以来长期水平滑动速率为3.18±1.23mm/a，长期垂直滑动速率为0.008±0.005mm/a。依据活动构造特征和碳14、光释光年龄测试结果，在大盈江流域梁河、盈江两个盆地识别出3次古地震事件，第一次古地震发生在距今2千年左右，发震段为南段盈江段，第二次古地震发生在距今7千年左右，发震段为南段盈江段，第三次古地震事件发生在距今3万年左右，发震段为南段盈江段和北段梁河段。更多还原

【Abstract】 Dayingjiang valley, locating in the southwest of Yunnan Province and thesoutheast corner of Himalayan tectonic belt, is the key area for the neotectonicresearch of Yunnan-Guizhou plateau. Lianghe basin and Yingjiang basin, locating atthe Dayingjiang valley, is the ideal area for the research of Quaternary sedimentation,morphogenesis, neotectonic and active tectonic, for the thick Quaternary strata,variety geomorphic types, strong active tectonic and multiple violent earthquake. But,there is little research work about Quaternary for this area until now.Based on the previous data and field geological survey, this paper discusses theQuaternary strata and active tectonic characteristics of Lianghe basin and Yingjiangbasin, and achieves the main progress as follows.This paper uses geological survey and section measuring, and sets upstratigraphic sequence on the base of the characteristics of Quaternary sediment types,geomorphology, matrrial composition, space distributing law, contact relation andattitude. Studies have been conducted to devide the Quaternary sedimentary strata forthese two basins, with4series,3formations and6members for Lianghe basin, and4series and2members for Yingjiang basin.By carefully studying these two basins`geomorphic feature and evolution, wecan correctly identify7terraces for Lianghe basin and4terraces for Yingjiang basin.specifically, the fifth and sixth terraces of Lianghe basin are lacustrine sediment, andthe others are fluvial deposition. These two basins are part inheritance Quatrtnaryfault basin, evoluting with four stages (valley, lake basin, disappearing of lake-basin,intermontane river). Each stage is closely associated with tectonic movement.By carefully studying the geometric structure, kinematical characteristics and dating results (C14and OSL), we can correctly divide the Dayingjiang Fault to twosegments——Yingjiang fault in the south and Lianghe fault in the north. Yingjiangfault is a Holocene NE-SW sinistral stike-slip fault. But Lianghe fault is a latePleistocene normal fault, and the fault strike changes from NE-SW to N-S. Using theformula, we can calculate the horizontal slip rate3.18±1.23mm/a，the vertical slip rate0.008±0.005mm/a.By carefully studying the trench and dating results (C14and OSL), we cancorrectly identify three palaeoseismic events. The latest palaeoseismic event is about2ka from nowadays, occurring within Yingjiang fault. the second palaeoseismic eventis about7ka from nowadays, occurring within Yingjiang fault. And the thirdpalaeoseismic event is about30ka from nowadays, occurring within Yingjiang faultand Lianghe fault.更多还原