三峡库首区高桥断裂带断层泥分形特征研究
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摘要
三峡水库蓄水前后,沿高桥断裂带发生了一系列地震活动。为了解断层泥特征与断裂活动的关系,在野外地质调查基础上,对高桥断裂带内的断层泥进行X光衍射和粒度分布测试。结果显示,高桥断裂带断层泥的粘土矿物含量一般低于35%,并且主要矿物为不具膨胀性的绿泥石和伊利石;断层泥分维值在2.20~2.67之间变化,表明高桥断裂带的运动方式以粘滑为主。断层力学性质和断层泥分维计算均表明其具有分段性,结合断裂附近的地震活动认为,北东段较南西段稳定,但不排除高桥断裂带未来有发生中强地震的可能性。
The Gaoqiao fault zone,which extends along the strike direction for more than 40 km,is a large-scale fault in the Three Gorges dam area.There were a series of seismic activities along the Gaoqiao fault zone before and after impoundment of the Three Gorges Reservoir.In this paper,the authors investigate the fractal dimension and mineralogy of the clay-rich fault gouge samples collected from the Gaoqiao fault zone based on grain size distribution and X-ray diffraction analysis.In this study,the main clay minerals of fault gouges are illite and chlorite,and the content of clay minerals is generally less than 35%,which is conducive to the stick-slip.The results demonstrate that the fractal dimension of fault gouges in the Gaoqiao fault zone range from 2.20 to 2.67,which indicates that the fault is essentially characterized by stick-slip.The mechanical properties of the fault and the fractal dimension of fault gouges show that it is divided into two segments.On the basis of the above,coupled with the analysis of seismicity,it is clear that we should pay attention to the moderate-sized earthquakes occurring on it in the future.
The Gaoqiao fault zone,which extends along the strike direction for more than 40 km,is a large-scale fault in the Three Gorges dam area.There were a series of seismic activities along the Gaoqiao fault zone before and after impoundment of the Three Gorges Reservoir.In this paper,the authors investigate the fractal dimension and mineralogy of the clay-rich fault gouge samples collected from the Gaoqiao fault zone based on grain size distribution and X-ray diffraction analysis.In this study,the main clay minerals of fault gouges are illite and chlorite,and the content of clay minerals is generally less than 35%,which is conducive to the stick-slip.The results demonstrate that the fractal dimension of fault gouges in the Gaoqiao fault zone range from 2.20 to 2.67,which indicates that the fault is essentially characterized by stick-slip.The mechanical properties of the fault and the fractal dimension of fault gouges show that it is divided into two segments.On the basis of the above,coupled with the analysis of seismicity,it is clear that we should pay attention to the moderate-sized earthquakes occurring on it in the future.
引文
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[8]易顺民,唐辉明.断层泥粒度成分的分形研究[J].地震地质,1995,17(2):185-191(Yi Shunmin,Tang Huiing.Fractal Research of Granulometric Composition in Fault Gouge[J].Seismology and Geology,1995,17(2):185-191)
[9]Babaie H A,Hadizadeh J,Babaei A.Self-Similar Cataclasis in the Saltville Thrust Zone,Knoxville,Tennessee[J].J Geophys Res,1995,100:18 075-18 084
[10]赵中岩,王毅.碎裂岩的分数维分析:理论、方法及地质意义[J].地质科学,1992(3):282-290(Zhao Zhongyan,Wang Yi.Fractal Analysis of Cataclastic Rocks:Theory,Techniques and Applications[J].Scientia Geologica Sinica,1992(3):282-290)
[11]邵顺妹,邹谨敞,滕瑞增.西秦岭北缘断裂带东段断层泥的粒度分布和显微构造特征[J].西北地震学报,1996,18(2):74-79(Shao Shunmei,Zou Jinchang,Teng Ruizeng.Grain Size Distribution and Microstructure Characters of the Fault Gouge in the East Section of Northern Edge of Western Qinling Mountain[J].Northwestern Seismological Journal,1996,18(2):74-79)
[12]张秉良,冯锦江,牛要芳,等.红河断裂带断层泥粘土矿物特征及其地震地质意义[J].地震地质,1989,11(3):96-97(Zhang Bingliang,Feng Jinjiang,Niu Yaofang,et al.Characteristics of Clay Minerals in Fault Gouges from Honghe Fault Zone and Their Seismogeologic Implication[J].Seismology and Geology,1989,11(3):96-97)
[13]张丽芬,姚运生,申学林,等.三峡水库地震类型:构造触发和非构造诱发地震及发震机理研究[J].大地测量与地球动力学,2014,34(4):77-82(Zhang Lifen,Yao Yunsheng,Shen Xuelin,et al.Study on Type and Focal Mechanism of the Earthquakes in Three Gorges Reservoir[J].Journal of Geodesy and Geodynamics,2014,34(4):77-82)
[14]Yao Y K,Wang Q L,Li J G,et al.Seismic Hazard Assessment of the Three Gorges Project[J].Geodesy and Geodynamics,2013,4(2):53-60
[2]马瑾,Moore D E,Summers R,et al.温度压力孔隙压力对断层泥强度及滑动性质的影响[J].地震地质,1985,7(1):15-24(Ma Jin,Moore D E,Summers R,et al.The Effect of Temperature,Pressure and Pore Pressure of Strength and Sliding Behavior of the Gouges[J].Seismology and Geology,1985,7(1):15-24)
[3]Sammis C G,King G,Biegel R.The Kinematics of Gouge Deformation[J].Pure Appl Geophys,1987,125:777-812
[4]夏金梧,李长安,曾新平.三峡工程库首区高桥断裂特征与地震活动性研究[J].大地测量与地球动力学,2008,28(2):8-15(Xia Jinwu,Li Changan,Zeng Xinping.Study on Characteristics and Seismic Activity of Gaoqiao Fault in the Head Area of Three Gorges Reservoir[J].Journal of Geodesy and Geodynamics,2008,(2):8-16)
[5]夏金梧,周乐群,刘世凯.鄂西秭归盆地及外缘主要断裂特征及活动性研究[J].水文地质工程地质,1996(1):10-14(Xia Jinwu,Zhou Lequn,Liu Shikai.The Main Characteristics of Fault and Its Activity in Zigui Basin,Western Hubei Province[J].Hydrogeology and Engineering Geology,1996(1):10-14)
[6]邓嘉农,周乐群.鄂西秭归盆地西北缘高桥断裂带特征及其活动性[J].华南地质与矿产,2003(3):18-23(Deng Jianong,Zhou Lequn.Features and Activity of Gaoqiao Fault Zone along the North-Western Margin of Zigui Basin in Hubei Province[J].Geology and Mineral Resources of South China,2003(3):18-23)
[7]邵顺妹.断层泥研究的现状和进展[J].高原地震,1994,6(3):51-55(Shao Shunmei.Present Condition and Progress of Fault Gouge Research[J].Earthquake Research in Plateau,1994,6(3):51-55)
[8]易顺民,唐辉明.断层泥粒度成分的分形研究[J].地震地质,1995,17(2):185-191(Yi Shunmin,Tang Huiing.Fractal Research of Granulometric Composition in Fault Gouge[J].Seismology and Geology,1995,17(2):185-191)
[9]Babaie H A,Hadizadeh J,Babaei A.Self-Similar Cataclasis in the Saltville Thrust Zone,Knoxville,Tennessee[J].J Geophys Res,1995,100:18 075-18 084
[10]赵中岩,王毅.碎裂岩的分数维分析:理论、方法及地质意义[J].地质科学,1992(3):282-290(Zhao Zhongyan,Wang Yi.Fractal Analysis of Cataclastic Rocks:Theory,Techniques and Applications[J].Scientia Geologica Sinica,1992(3):282-290)
[11]邵顺妹,邹谨敞,滕瑞增.西秦岭北缘断裂带东段断层泥的粒度分布和显微构造特征[J].西北地震学报,1996,18(2):74-79(Shao Shunmei,Zou Jinchang,Teng Ruizeng.Grain Size Distribution and Microstructure Characters of the Fault Gouge in the East Section of Northern Edge of Western Qinling Mountain[J].Northwestern Seismological Journal,1996,18(2):74-79)
[12]张秉良,冯锦江,牛要芳,等.红河断裂带断层泥粘土矿物特征及其地震地质意义[J].地震地质,1989,11(3):96-97(Zhang Bingliang,Feng Jinjiang,Niu Yaofang,et al.Characteristics of Clay Minerals in Fault Gouges from Honghe Fault Zone and Their Seismogeologic Implication[J].Seismology and Geology,1989,11(3):96-97)
[13]张丽芬,姚运生,申学林,等.三峡水库地震类型:构造触发和非构造诱发地震及发震机理研究[J].大地测量与地球动力学,2014,34(4):77-82(Zhang Lifen,Yao Yunsheng,Shen Xuelin,et al.Study on Type and Focal Mechanism of the Earthquakes in Three Gorges Reservoir[J].Journal of Geodesy and Geodynamics,2014,34(4):77-82)
[14]Yao Y K,Wang Q L,Li J G,et al.Seismic Hazard Assessment of the Three Gorges Project[J].Geodesy and Geodynamics,2013,4(2):53-60