四川龙门山安县-灌县断裂带的特征——以汶川地震断裂带科学钻探3号孔(WFSD-3)岩心为例
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摘要
汶川地震断裂带科学钻探(WFSD)是由科技部、国土资源部和中国地震局联合组织实施的汶川地震断裂带科学钻探研究项目,计划在同震地表破裂带(龙门山映秀-北川断裂安县-灌县断裂)的上盘布置5口科学群钻:WFSD-1、WFSD-2、WFSD-3、WFSD-3P和WFSD-4,其中WFSD-3和WFSD-3P位于龙门山前山断裂安县-灌县断裂的上盘。以WFSD-3钻孔岩心为研究对象,进行详细的岩石学、构造学、野外编录等研究。WFSD-3钻孔岩心中的断裂岩主要由断层角砾岩、碎裂岩和断层泥组成,未见假玄武玻璃。钻孔中存在26条规模不等的断裂带,断裂密度显示FZ634、FZ1215和FZ1250为主要断裂带,而FZ1250可能为2008年汶川地震的主滑移带。安县-灌县断裂在地表和WFSD-3P、WFSD-3钻孔岩心中的断层倾角分别约为60°、46°和38°,显示安县-灌县断裂倾角从地表至深部逐渐变缓,为一铲式逆冲断层。
Wenchuan Earthquake Fault Zone Scientific Drilling(WFSD) was organized jointly by Ministry of Science and Technology,Ministry of Land and Resources and China Bureau of Seismology.The WFSD project plans to drill five scientific wells on the hanging wall of the co-seismic surface rupture zone,including the Yingxiu-Beichuan fault and the Anxian-Guanxian fault in Longmenshan area.The five drilling holes include WFSD-1,WFSD-2,WFSD-3,WFSD-3P and WFSD-4.The WFSD-3 and WFSD-3P drill holes are located on the hanging wall of the Anxian-Guanxian fault.Basic studies were carried out for the WFSD-3 drilling cores in such aspects as petrology,structural geology and borehole logging.The results show that the fault-rocks in the WFSF-3 contain fault breccia,cataclastic rock and fault gouge.The pseudotachylite does not appear in this well.Twenty-six fault zones were detected in this well,including the three main major fault zones of FZ634,FZ1215 and FZ1250,with the FZ1250 being the possible primary slip zone during the 2008 Wenchuan earthquake.The dip angles of the trench,WFSD-3P and WFSD-3 are respectively about 60°,46° and 38°.The variation of the dip angle indicates that the Anxian-Guanxian fault is a listric thrust fault with low dip angle.
引文
[1]Ma Kuofong,Tanaka H,Song Shengrong,et al.Slip zone and energeticsof a large earthquake from the Taiwan Chelungpu-fault DrillingProject[J].Nature,2006,444:473-476.
    [2]李海兵,王宗秀,付小方,等.2008年5月12日汶川地震(Ms8.0)地表破裂带的分布特征[J].中国地质,2008,35(5):803-813.
    [3]李勇,黄润秋,Densmore A L,等.龙门山彭县-灌县断裂带活动构造与地表破裂[J].第四纪研究,2009,29(3):403-415.
    [4]李海兵,付小方,Jerome VAN DER WOERD,等.汶川地震(Ms8.0)地表破裂及其同震右旋斜向逆冲作用[J].地质学报,2008,82(12):1623-1643.
    [5]徐锡伟,闻学泽,叶建青,等.汶川Ms8.0地震地表破裂带及其发震构造[J].地震地质,2008,30(3):597-629.
    [6]付碧宏,时丕龙,张之武,等.四川汶川Ms8.0大地震地表破裂带的遥感影像解析[J].地质学报,2008,82(12):1679-1687.
    [7]刘静,张智慧,文力,等.汶川8级大地震同震破裂的特殊性及构造意义[J].地质学报,2008,82(12):1707-1722.
    [8]李海兵,司家亮,裴军令,等.汶川地震(Ms8.0)地表破裂过程探讨[J].第四纪研究,2010,30(4):677-698.
    [9]王二七,孟庆任,陈智梁,等.龙门山断裂带印支期左旋走滑运动及其大地构造成因[J].地学前缘,2001,8(2):375-384.
    [10]李勇,周荣军,Densmore A L,等.青藏高原东缘龙门山晚新生代走滑-逆冲作用的地貌标志[J].第四纪研究,2006,26(1):40-52.
    [11]唐荣昌,文德华,黄祖智,等.松潘龙门山地区主要活动断裂带第四纪活动特征[J].中国地震,1991,7(3):64-71.
    [12]李勇,周荣军,Alexander L Densmore,等.青藏高原东缘大陆动力学过程与地质响应[M].北京:地质出版社,2006:134.
    [13]邓起东,陈社发,赵小麟,等.龙门山及其邻区的构造和地震活动及动力学[J].地震地质,1994,16(4):391-403.
    [14]Lin A M,Ren Z K,Jia D,et al.Co-seismic thrusting rupture andslip distribution produced by the 2008 Mw 7.9 Wenchuan earth-quake,China[J].2009,Tectonophysics,471:203-215.
    [15]J Liu-Zeng,Z Zhang,L Wen,et al.Co-seismic ruptures of the 12May 2008,Ms 8.0 Wenchuan earthquake,Sichuan:East-westcrustal shortening on oblique,parallel thrusts along the eastern edgeof Tibet[J].Earth and Planetary Science Letters,2009,286(3/4):355-370.
    [16]孙岩,韩克从.断裂构造岩带的划分[M].北京:科学出版社,1985:163.
    [17]Sibson R H.Fault mechanisms[M].Geological Society London,1977,133:191-213.
    [18]张西娟,曾庆利,马寅生.断裂带中的流体活动及其作用[J].西北地震学报,2006,28(3):274-279.
    [19]林茂炳,苟宗海,王国芝,等.龙门山中段地质[M].成都:成都科技大学出版社,1996:1-53.
    [20]王焕,李海兵,裴军令,等.汶川地震断裂带结构、岩性特征及其与地震活动的关系[J].第四纪研究,2010,30(4):768-778.
    ①四川省地质局第二区域地质测量队.1∶20万灌县幅、茂汶幅、绵阳幅和成都幅地质图.1967-1975.
    ②四川省地质矿产局化探队.1∶5万绵竹幅地质图.1991-1994.

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