青藏高原东北缘达日断裂中段晚第四纪活动特征及其构造转换形式研究

Taking the middle Segment of Dari fault as the research object, which striking to NW is the most representative fault in BayanHar block. The study extract key information from surface rupture left by Dari earthquake. Using field investigation, TM images, EDM to interpretate deformation features and assemble pattern of landform in large-scale, meso-scale and small-scale. Determining typical region and key positions to survey fracture types of the active fault, we will definite geometrical morphology, tectonic deformation pattern and activity characteristics in the inner of BayanHar block. Next we will analysis on intersected relations and tectonic transfer style among nearby branch active faults. Based on the research, the study will attention to deformation features, activity regularity and recurrence intervals of lager earthquake between main faults and branch faults. It is very important to understanding tectonic transfer style and its tectonic significance in the BayanHar block area, and establishment a modle of the tectonic transfer style. So the kinematics model and dynamic process will be achieved, and it is a good example for the similar study in the BayanHar block area. fault as the research object, which striking to NW is the most representative fault in BayanHar block. The study extract key information from surface rupture left by Dari earthquake. Using field investigation, TM images, EDM to interpretate deformation features and assemble pattern of landform in large-scale, meso-scale and small-scale. Determining typical region and key positions to survey fracture types of the active fault, we will definite geometrical morphology, tectonic deformation pattern and activity characteristics in the inner of BayanHar block. Next we will analysis on intersected relations and tectonic transfer style among nearby branch active faults. Based on the research, The study will attention to deformation features, activity regularity and recurrence intervals of lager earthquake between main faults and branch faults. It is very important to understanding tectonic transfer style and its tectonic significance in the BayanHar block area, and establishment a modle of the tectonic transfer style. So the kinematics model and dynamic process will be achieved, and it is a good example for the similar study in the BayanHar block area.

以达日断裂中段作为巴颜喀拉地块内部最具代表性的NW向次级断裂为研究对象，从1947年7¾级达日地震遗留的地震地质资料中提取关键信息，利用地表测量、TM图像、数字高程模式图和航片，进行大尺度、中尺度和小尺度构造地貌变形特征及组合样式的解译，以达日断裂中段的晚第四纪地貌表现形式为切入点，确定典型区域和关键部位，深入调查该活动断裂的发育规模、期次、地貌错位以及构造组合等，明确其在巴颜喀拉地块内部的空间几何形态、活动规律、运动学特征以及构造地貌的响应过程，分析地块内相邻次级活动断裂相互之间的构造转化形式及交接关系，探讨其与主干边界活动断裂的构造变形样式、分段性特征以及活动性规律之间的相互关系，充分认识达日断裂中段在巴颜喀拉地块区域中的构造转换形式及构造意义，建立区域构造转换形式的地质模型，为研究巴颜喀拉块体内部次级活动断裂、青藏高原东北缘活动构造的运动学模型以及动力学过程提供范例和科学依据。

本项目以1947年7¾级达日地震遗留的地震地表破裂为切入点和关键信息，结合不同尺度的图像影像资料，利用TM图像、数字高程模式图像和航片进行大尺度、中尺度和小尺度的构造地貌变形特征及组合样式的解译，对达日断裂中段及典型区域（桑日麻、昂苍沟、日查以及吉迈等地）地表微地貌的标志物和水系标志进行了精确的测量，厘定了达日地震地表破裂的空间展布范围，开展了达日断裂中段活动断裂的几何展布形态、变形样式、组合形式、交接关系、第四纪活动特点、构造地貌响应过程等方面的研究，定量化的反映了达日断裂中段活动断裂的分段性特征、运动形式和运动速率以及活动构造与构造地貌的响应关系，探讨了达日断裂中段在巴颜喀拉地块内部所发挥的构造转换意义。本项研究成果可为巴颜喀拉地块的大地构造特征和动力学机制以及青藏高原东北缘活动构造的运动学模型和动力学过程提供研究思路和理论依据。