龙门山谢家店震积体发育特征及其控制因素分析

【作者】 王威；

【导师】 刘全稳；

【作者基本信息】 西南石油大学 ， 开发地质学， 2010， 硕士

【摘要】 2008年5月12日下午2点28分,在中国四川西部龙门山主断裂面内靠近映秀镇的山区发生了Ms 8级地震,强烈的地震动造成了巨大的社会经济损失和人员伤亡,摧毁了大量的基础与公共设施。汶川地震的发生使人们更加深刻地认识到在研究龙门山地区活动断裂和地壳稳定性的同时,必须重视地震引发的地震地质体灾害的研究,这也是目前灾区恢复重建过程中迫切需要解决的问题。5·12特大地震给我们带来了巨大的灾难,也为地震科学研究领域带来了空前的机遇。本论文在区域地质考察与地质基础研究的基础上,主要针对5·12汶川地震重灾区彭州市龙门山镇谢家店震积体地质特征,开展基础地质学与地球动力学研究。首先从区域地质背景和地理环境入手,结合地质考察资料和前人研究成果,解析了震积体发育过程及其特征,分析了地震地质体类型及特征以及各地质体相互之间的关系,提出了地震震积体相关的基本概念与理论,揭示了震积体的诱发机制和发育的控制因素,阐明了其强中纬力的动力学机制及其与龙门山断裂带紧密相连的特性,以探讨其在地质灾害学与油气地质学等方面的重要意义,从而开展全面的、深入细致的研究：具体研究内容如下：(1)发育过程及其特征分析。在对比分析基本地震地质体的发育过程、特征的基础上,结合野外地质调查资料,解析震积体发育过程及碎屑物岩性特征。总体上,龙门山谢家店震积体大致可以分为3段：①启动段、②刨蚀段、③堆积段；3体：①冲击体、②刨蚀体、③堆积体。并从震积体碎屑物的岩性、结构特征、构造与碎屑物颜色特征、与油气的关系等方面展开分析。指出刨蚀体储集性能较好,可作为有利的油气储集带。其与大断裂紧密相连的特性,表明其有良好的油气运移通道。(2)地震地质体特征及对比。立足于现有的地震地质体的类型及基本特征,系统介绍了崩塌、滑坡、碎屑流、震积岩等发育特征及成因规律,通过对比分析,提出了震积体的概念。(3)诱发机制及其发育控制因素。通过对龙门山断裂带地球动力学、大地构造地质、地震地质学等方面的分析,揭示震积体的诱发机制及其控制因素。依据地震起始破裂点位于北纬约31.1°,东经约103.3°,龙门山断裂带上的各点的纬度范围为31°00’N-31°50’N、经度范围为103°29’E-104°45’E,强中纬力在北半球、南半球的作用范围为北纬21°33’-68°27’、南纬21°33’-68°27’,由此断定,龙门山断裂带受明显的强中纬力作用。强中纬力作用于龙门山断裂带,为龙门山断裂带的活动提供动力。(4)探讨地质学意义。根据地震活动产生的动力学、地质学背景,以及地震活动对地质灾害、矿产资源分布规律的影响,阐述其在地质灾害防治、油气聚集与分布等领域的重要意义。更多还原

【Abstract】 There had been a serious earthquake in mountain area where is near Yingxiu town in Western Sichuan Province of China at 2:28 p.m on May 12,2008. The earthquake magnitude is about 8.0. Violent shake caused huge economic losses and casualties. Also, a lot of basic and public facilities were destroyed. Wenchuan Earthquake made us realize profoundly that we must pay more attention to the geological disaster research when we studied active fault belt of Longmen Mountain and the stability of earth crust. In the process of reconstruction of the disaster area, geological disaster is problem which is needed to be solved eagerly. As a result of the severe situation of disaster mitigation, we must pay more attention to mechanism research and prevention research of landside and collapse. Wenchuan Earthquake bought great disaster for us and created an opportunity for earthquake science research. Meantime, it provided data for the crustal stress function research to the forming and distribution of reservoir.Based on the region geological study and fundamental geology research. aiming at Xiejiadianzi village in Longmenshan town of Pengzhou city, the paper describes geological disaster characteristic of rock mass which is formed by seismic deposition and does some research about basic geology and earth dynamics. According to the geological background of region, geographical environment, data of geological survey and research findings,the paper analyses type and characteristic of geological disaster,presents basic concept and theory of rock mass which formed by seismic deposition, explains growing process and characteristic of it, reveals evoked mechanism and control factor of it. Then, the important meaning of rock mass which formed by seismic deposition on science of geological disaster and geology is discussed. The concrete study is given as follows:(1) Growing process and the analysis of its characteristic. According to the growing process of geological disaster, growing characteristic of geological disaster, the data of geological survey, growing process and characteristic are explained.Generally speaking, landslide-debris flow is divided three sections:①sart section、②planed erosion section、③accumulation section; three Body:①impact body、②plane corrosion body、③accumulation body.And detritus from the integrated seismic lithology,structural characteristics, structure and color characteristics of clastic material, and the relationship between oil and gas analysis in such areas.The reservoir quality of the fourth section is good and it can be good place for preserving oil and gas. The phenomenon of rock mass which formed by seismic deposition reveals that crustal stress has influences on forming mechanism and distribution rule of reservoir. It has strong relation with deep fracture and there is good way of oil and gas migration in it.(2) Type and characteristic of geological disaster. According to the type and characteristic of geological disaster, the paper introduces growing feature and forming rule of collapse, landslide, debris flow, mud and stone flow, seismite. The concept of rock mass which formed by seismic deposition is proposed by analysis. (3) Evoked mechanism and control factor when growing. By analysis of earthquake dynamics, architectonic geology, terrain and geomorphy, rock source, the paper reveals reasons of growing and control factor of growing. Based on earthquake rupture initiation point at latitude of about 31.1°, longitude of about 103.3°, the Longmen Shan fault zone on a range of points of latitude 31°00’N-31°50’N, longitude range 103°29’E-104°45’E, strong force in the latitude in the northern hemisphere, southern hemisphere’s role in the range of latitude 21°33’-68°27’, latitude 21°33’-68°27’. thus determined, the Longmen Shan fault zone by obvious strong force in the weft. Strong mid-latitude force on the fault zone, as the activities of the Longmen Shan fault zone to power。(4) Discuss its meaning of geology. According to the dynamics of earthquake, geology, earthquake influence on geological disaster and mineral source distribution, the paper describes the meaning of rock mass which formed by seismic deposition in some research field, such as the prevention of geological disaster, accumulation and distribution of oil and gas.更多还原