【作者】 姚维岭；

【导师】 陈建强； 李岩峰；

【作者基本信息】 中国地质大学(北京) ， 地理学， 2012， 硕士

【摘要】 研究区位于四川省西部，川西高原理塘县境内。理塘断裂带的定位和定性研究是解决该断裂带晚第四纪以来活动性评价的基础性工作，也是评价该断裂带地震危险性所要解决的基本问题。本文应用差分GPS测量方法，沿理塘活动断裂带地表破裂形迹，对目标区断层陡坎、断塞塘、鼓包、地裂缝、位错等断裂微地貌进行调查，研究理塘断裂带的空间展布及断裂活动规律特征。应用差分GPS测量方法调查理塘断裂带断裂微地貌的综合实践表明：断塞塘、鼓包微地貌对断裂几何形态和定位认识具有重要指示作用；断层陡坎和位错地貌的垂直和水平位移量反映了断裂活动的期次性和强弱性；地裂缝的排列方式和组合形态反映了断裂形成时的构造应力状态。本文通过对理塘断裂带重点段落微地貌的差分GPS调查，支持了前人对该断裂带研究的相关结论：认为理塘断裂带由F1、F2、F3三条次级断裂组成，整体走向北西，倾向北东或南西，倾角较陡；F3断裂的构造应力状况是在一组近东西向的主压应力作用下，形成了一对北西和南东向的力偶，产生左旋走滑运动的结果；理塘盆地、甲洼—给忠盆地、德巫盆地等第四纪盆地均受到整条断裂带逆冲分量的构造影响。对目标断裂F3断裂的展布位置、活动性质及1948年7.3级地震宏观震中位置等有了一些新认识：第一，F3断裂并不连续。根据野外调查结果和地震破裂段落划分原则，将F3断裂在交德分水岭附近分为北西和南东两段，各长约20km，走向差异约10°左右。第二，F3断裂沿断裂面和倾向面均具波状起伏，北西段断层倾向北东，倾角80左右；南东段断层倾向南西，倾角65°左右。第三，发现F3断裂1948年7.3级大地震的宏观震中位置可能位于29°30’57.33"N，100°32’17.55"E附近。本文首次采用差分GPS高精度测量手段，对应用差分GPS测量手段进行高原地区活动断裂微地貌调查的可行性进行了评价。在获得丰富的第一手资料基础上，对理塘断裂带F3断裂地表微地貌进行调查，验证了前人的研究结论并得出了一些新的认识，丰富了该断裂带的研究成果，特别是对地表裂缝带的精确定位及断裂带微地貌演化特征方面的研究。更多还原

【Abstract】 The study area is located in Western Sichuan Plateau, Litang county. Thepositioning and qualitative research work of Litang faults zone is the basis ofevaluating the activities of this faults zone since The Late Quaternary. Surveying byDGPS, along the faults traces of study area, this paper investigated the sag ponds,scarps, bulges and other microrelief of study area, then analysed it’s spatialdistribution and rupture characteristics.The application of DGPS surveying practices showing: the sag ponds and bulgerevealed the fracture geometry and positioning; displacement of scarps anddislocations of study area reflected the fault activities; ground fissures explained thetectonic stress state when the fault forming.Through the research wrok of study area, this paper verifed the representativestudy results that existed previously: Litang faults zone was consisted with3secondary faults, F1, F2and F3fault; Litang faults zone striked NW, slip NE or SW,it’s angle was dip; the tectonic stress of F3was in a group of principal compressivestress nearly east to west, then formed a pair of north and west, two parallel to eachother, the left-lateral strike-slip movement formed the thrust dip-slip of F3faults; TheQuaternary basin of this area, Litang, Jiawa-Geizhong, Dewu basin was influenced byF3fault zones.This paper proposed some new opinions about the characteristics and activitiesof F3fault, the magnitude earthquake epicenter in1948. Firstly, the F3fault is notcontinuous. According to the faults dividing principles and field surveying results, theF3fault should be divided into two sections, NW and SE, each section is about20kmlong and there is10°strikeward difference between the two sections. Secondly, the F3falult surface along with wavy tendency, the NW section dips NE, dip angle is about80; the SE section dips SW, angle is about65. Thirdly, according to the fields survey,this paper proposed that the epicenter location of MS7.3earthquake in1948maybe29°30’57.33"N,100°32’17.55"E. This paper adopted differential GPS measuring method for the research work ofstudy area, evaluated the activities and the feasibility about applying differential GPSmeasurement for micro geomorphology survey in plateau area. At the foundation ofacquiring rich first hand materials, this paper surveyed the miro geomorphology of F3fault, verifed the representative study results that existed previously and proposedsome new visions. The research work of this paper intensified the results of Litangfaults zone, especially for the reaearch about accurate positioning of surface faultfissures and Geomorphology evolution characteristics.更多还原