贵州兴义地区活动构造及其对地貌的影响

发布时间：2018-06-26 00:21

  本文选题：活动构造 + 弥勒-师宗断裂　； 参考：《成都理工大学》2017年硕士论文

【摘要】：近年来地质灾害频繁发生,活动构造的研究备受关注。活动构造在地质灾害预测与预防、工程稳定性评价以及现代地球动力学研究中具有重要意义,地震活动的频繁发生与活动构造的分布有着极其密切的关系。因此,查明活动断裂的分布、活动特征是很有必要的。研究区位处滇东—黔西隆起区,新生代以来受青藏高原隆升的影响,区内河流纵向切割、地形破碎、山高谷深、坡陡流急。对研究区地貌特征的分析及活动断裂的提取可以作为未来工程施工、地灾防范、地震预测的依据。本文选取兴义地区为研究区,通过对DEM、ETM数据的处理与分析,对研究区高程、坡度地貌信息、活动断裂的提取及地形条带剖面分析,并结合野外调查结果,取得以下认识:1)通过人机交互的手段,应用ETM数据进行742波段彩色合成,结合Google Earth高清图像,在研究区共提取了34条活动断裂,其中在安龙断裂中段识别出一小型拉分盆地,其中长约2.3-2.7km,宽约0.7-0.8km,其长宽比介于4:1~3:1之间,具有拉分盆地的特征。此外,根据遥感解译结果,北东向断裂具有多期活动特征,先前北西、近南北向断层明显被北东向断裂切割,结合野外地质调查发现小羊角冲断裂晚新生代是一条右行-逆冲断裂。2)地震活动是地壳运动的一种特殊表现形式,常与活动断裂息息相关。近年来,地震频繁发生严重危及到人类的生命及财产安全。通过解译的活动断裂分布图与地震数据叠加,可以看出研究区内地震分布很不均匀,4级以上地震主要分布于活动断裂附近常单独出现;小震主要集中在北东向以及近南北向断裂附近呈带状分布。3)通过DEM高程、坡度及条带剖面分析,晚新生代以来研究区中西部,明显受断裂活动控制,河谷形态呈深“V”型,其中在雄武地区,受革上断裂带的影响,强烈的抬升造成北西侧沿木扎断裂断陷,最大上升降量达400m;其次升降运动受老断裂影响具有不均衡性和间歇性的特点,山地中广泛分布层状地貌,存在着四级夷平面、四层溶洞及三级河流阶地。4)根据溶洞、河流阶地光释光年龄数据显示,仅获得Ⅱ、Ⅰ级阶地及古溶洞年龄,其中Ⅱ级阶地获得两个年龄数据,分别为57.4±5.7Ka和61.6±6.2Ka,Ⅰ级阶地年龄为35.1±3.5Ka,根据各级阶地的相对河拔高度为110m和3m,Ⅱ级阶地依据获取的最老年龄计算出平均抬升速率为4.04m/Ka,Ⅰ级阶地的平均抬升速率为0.08m/Ka;古溶洞中所获得的年龄为30.9±3.1Ka,拔河高度约为26m,平均抬升速率为0.84m/Ka。
[Abstract]:Geological hazards occur frequently in recent years, and the study of active structures has attracted much attention. Active structures play an important role in geological hazard prediction and prevention engineering stability evaluation and modern geodynamics research. The frequent occurrence of seismic activity is closely related to the distribution of active structures. Therefore, it is necessary to find out the distribution and characteristics of active faults. The study area is located in the uplift region of eastern Yunnan and western Guizhou, which has been affected by the uplift of Qinghai-Tibet Plateau since the Cenozoic. The rivers in the region are cut longitudinally, the topography is broken, the mountain is high and the valley is deep, and the slope is steep. The analysis of geomorphological features and the extraction of active faults in the study area can be used as the basis for future engineering construction, disaster prevention and earthquake prediction. In this paper, Xingyi area is selected as the study area. By processing and analyzing the data of demm ETM, the elevation, slope geomorphology information, active fault extraction and topographic strip section analysis of the study area are analyzed, and the results of field investigation are combined. Get the following understanding: 1) by means of human-computer interaction, using ETM data for 742 band color synthesis, combined with Google Earth high-definition images, 34 active faults were extracted in the study area, among which a small pull basin was identified in the middle of the Anlong fault. Among them, the length is about 2.3-2.7km, the width is about 0.7-0.8km, and the aspect ratio is between 4: 1 and 3: 1, which is characterized by a pull-apart basin. In addition, according to the results of remote sensing interpretation, the NE-trending fault has the characteristics of multi-stage activity, and the NW and NNE faults were obviously cut by the NNE fault. Combined with the field geological investigation, it is found that the late Cenozoic of the Xiaoyangjiaochong fault is a right-lateral thrusting fault .2) the seismicity is a special form of crustal movement, which is often closely related to the active fault. In recent years, frequent earthquakes have seriously endangered the safety of human life and property. Through the interpretation of the active fault distribution map and seismic data superposition, it can be seen that the earthquake distribution in the study area is very uneven M 鈮，

本文编号：2068183