中条山北麓断裂中南段全新世地震事件的初步研究
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摘要
通过对中条山北麓断裂进行探槽研究,揭露了全新世以来,断裂中段和南段的3次古地震事件,包括1次发生在8 570~8 010a BP、贯通断裂中段和南段的8级以上特大地震,以及4 800~6 010a BP和2 110~320a BP发生的2次7级左右的大地震,地震复发间隔约为3 500a。研究表明,中条山北麓断裂的南段和中段在全新世发生过多次活动,活动性较强。
Shanxi Graben System( SGS) is a NNE-trending tectonic system located in the eastern and southern edges of Ordos Block and between Yinshan tectonic zone and Qinling tectonic zone.Composited with a series of NNE-,NE-trending graben basins,SGS is an important seismic zone in North China. Yuncheng Basin locates in the southern end of SGS,and is the deepest basin of the system. It is a half-graben with a shallow northern part and a deep southern part. As the south and east boundary of Yuncheng Basin,the North Zhongtiaoshan Fault Zone( NZFZ) played a key role in the development of the topology and tectonics setting of Yuncheng Basin. NZFZ is a normal fault zone,NE-to NEE-trending and 130 km long. This fault zone can be divided into 3 segments: the south,the middle,and the north segment,and there are no historical M≥7,but only 3 M = 6 have taken place. Previous study suggests that the tectonic activity in this area is low and the earthquake interval is relatively long; seismic activity in the north and south segments is the weakest: the earthquake recurrence interval in the north segment is >50ka and it has not been active for >50ka,the interval of the south segment is ~ 12 ka and its last movement is about 7ka ago. Our work tells a different story: based on thorough fieldwork,satellite imagery analysis,and trench investigation,we found that there have been multiple earthquake events taking place in all of the 3 segments during Holocene. This study includes two trenches that locate in the south and middle segments of NZFZ,each of them renders 3 paleo-earthquake events: a 10 570 ~ 8 010 a BP event, an around 6670 ~ 6 550 a BP event,and a 2 110 ~ 320 a BP event in TC-1; a 7 930 ~ 11 300 a BP event,a4 800 ~ 6 010 a BP event,and a 2 680 a BP event in TC-2. Through comparing these events with other 2 trenches in the middle segment of NZFZ( a XTC trench that renders a 19 980 a BP event and a 8 570 ~ 7 780 a BP event with >2. 2m vertical displacement; a XLC trench that renders a8 980 ~ 7 340 a BP event with ~ 1. 8m vertical displacement),we identified: a 8 570 ~ 8 010 a BP event which broke through both middle and south segment of NZFZ with a largest known vertical displacement of > 2. 2m and 95 km surface rupture,a 4 800 ~ 6 010 a BP and a 2 110 ~ 320 a BP event with 7 ~ 30 km surface ruptures and largest known vertical displacements of 0. 7m and 1. 2m,respectively. The recurrence interval of these events is about 3 500 a. Calculated with empirical formula of normal fault in North China,the magnitude of the 8 570 ~ 8 010 a BP earthquake should be at least 8. 0,and the magnitudes of the 4 800 ~ 6 010 a BP and 2 110 ~ 320 a BP events are both ≈7. 0. These findings suggest that,as a Holocene active fault zone which made up with multiple faults,the middle and south segments of NZFZ have shown strong seismic activity and have triggered multiple earthquake events during the Holocene. Contrary to previous study,the activity of south segment might not be the weakest,and it is possible that the south segment is more seismic active than the middle segment.
引文
程绍平,杨桂枝.2002.山西中条山断裂带的晚第四纪分段模型[J].地震地质,24(3):289—302.CHENG Shao-ping,YANG Gui-zhi.2002.Late Quaternary segmentation model of the Zhongtiaoshan Fault,ShanxiProvince[J].Seismology and Geology,24(3):289—302(in Chinese).
    邓起东,闻学泽.2008.活动构造研究:历史、进展与建议[J].地震地质,30(1):1—30.DENG Qi-dong,WEN Xue-ze.2008.A review on the research of active tectonics:History,progress and suggestions[J].Seismology and Geology,30(1):1—30(in Chinese).
    邓起东,于贵华,叶文华.1992.地震地表破裂参数与震级关系的研究[A].见:中国地震局地质研究所编.活动断裂研究(2).北京:地震出版社.247—264.DENG Qi-dong,YU Gui-hua,YE Wen-hua.1992.Relationship between earthquake magnitude and parameters ofsurface ruptures associated with historical earthquakes[A].In:Institute of Geology,China EarthquakeAdministration(ed).Research of Active Fault(2).Seismological Press,Beijing.247—264(in Chinese).
    杜鹏,柴炽章,廖玉华,等.2009.贺兰山东麓断裂南段套门沟—榆树沟段全新世活动与古地震[J].地震地质,31(2):256—264.doi:10.3969/j.issn.0253-4967.2009.02.006.DU Peng,CHAI Chi-zhang,LIAO Yu-hua,et al.2009.Study on Holocene activity of the south segment of the easternpiedmont fault of Helan Mountains between Taomengou and Yushugou[J].Seismology and Geology,31(2):256—264(in Chinese).
    郭慧,江娃利,谢新生.2012.山西交城断裂北端及中段3个大型探槽全新世断错现象分析[J].地震地质,34(1):76—92.doi:10.3969/j.issn.0253-4967.01.008.GUO Hui,JIANG Wa-li,XIE Xin-sheng.2012.Analysis of Holocene faulting phenomena revealed in the threetrenches along the northern and central Jiaocheng Fault,Shanxi[J].Seismology and Geology,34(1):76—92(in Chinese).
    兰青龙,苏宗正.1995.山西地震基本烈度特点分析[J].山西地震,81(2):9—13.LAN Qing-long,SU Zong-zheng.1995.Analysis for the feature of the basic seismic intensity in Shanxi[J].Earthquake Research in Shanxi,81(2):9—13(in Chinese).
    毛凤英,张培震.1995.古地震研究的逐次限定方法与新疆北部主要断裂带的古地震研究[A].见:中国地震局地质研究所编.活动断裂研究(4).北京:地震出版社.153—164.MAO Feng-ying,ZHANG Pei-zhen.1995.Progressive constraining method in paleoseismic study and paleoearthquakesalong the major active faults in northern Xinjiang[A].In:Institute of Geology,China Earthquake Administration(ed).Research of Active Fault(4).Seismological Press,Beijing.153—164(in Chinese).
    冉勇康.2001.华北正断层古地震识别标志及不确定性问题的思考[A].见:卢演俦等编.新构造与环境.北京:地震出版社.282—292.RAN Yong-kang.2001.A discussion about the mark and the uncertainty of paleo-earthquake of North China normalfaults[A].In:LU Xian-chou et al.(ed).Neotectonic and Environment.Seismological Press,Beijing.282—292(in Chinese).
    冉勇康,邓起东.1999.古地震学研究的历史、现状和发展趋势[J].科学通报,44(1):12—20.RAN Yong-kang,DENG Qi-dong.1999.The history,current status and progress of paleoseismology[J].ChineseScience Bulletin,44(1):12—20(in Chinese).
    司苏沛,李有利,吕胜华,等.2014.中条山北麓断裂盐池一带全新世古地震事件和滑动速率研究[J].中国科学(D辑),44(9):1958—1967.doi:10.1007/s11430-014-4887-3.SI Su-pei,LI You-li,LSheng-hua,et al.2014.Holocene slip rate and paleoearthquake records of the Salt Lakesegment of the northern Zhongtiaoshan Fault,Shanxi Province[J].Science China(Ser D),57(9):2079—2088.
    苏宗正,安卫平,程新源.1993.华北新构造分区与潜在震源划分问题[J].山西地震,75(4):19—28.SU Zong-zheng,AN Wei-ping,CHENG Xin-yuan.1993.Neotectonic regionalization and division of potential sourcearea in North China[J].Earthquake Research in Shanxi,75(4):19—28(in Chinese).
    苏宗正,程新源,安卫平,等.2001.山西运城盆地的中条山断裂[A].见:中国地震局地质研究所编.活动断裂研究(8).北京:地震出版社.120—130.SU Zong-zheng,CHENG Xin-yuan,AN Wei-ping,et al.2001.Study on Zhongtiaoshan active fault in YunchengBasin of Shanxi Province,China[A].In:Institute of Geology,China Earthquake Administration(ed).Researchof Active Fault(8).Seismological Press,Beijing.120—130(in Chinese).
    田建梅,李有利,司苏沛,等.2013.中条山北麓中段洪积扇上全新世断层陡坎的发现及其新构造意义[J].北京大学学报(自然科学版),49(6):986—992.TIAN Jian-mei,LI You-li,SI Su-pei,et al.2013.Discovery and neotectonic significance of fault scarps on alluvialfans in the middle of northern piedmont of the Zhongtiao Mountains[J].Acta Scientiarum NaturaliumUniversitatis Pekinensis,49(6):986—992(in Chinese).
    王乃樑,杨景春,夏正楷,等.1996.山西地堑系新生代沉积与构造地貌[M].北京:科学出版社.206—218,381—392.WANG Nai-liang,YANG Jing-chun,XIA Zheng-kai,et al.1996.The Cenozoic Sedimentary and TectonicGeomorphology of Shanxi Graben System[M].Science Press,Beijing.206—218,381—392(in Chinese).
    王强,李彩光,田国强.2000.7.1Ma以来运城盆地地表系统巨变及盐湖形成的构造背景[J].中国科学(D辑),30(4):420—428.WANG Qiang,LI Cai-guang,TIAN Guo-qiang,et al.2000.Tremendous change of the earth surface system andtectonic setting of salt-lake formation in Yuncheng Basin since 7.1Ma[J].Science in China(Ser D),30(4):420—428(in Chinese).
    徐锡伟,邓起东,董瑞树,等.1992.山西地堑系强震的活动规律和危险区段的研究[J].地震地质,14(4):305—316.XU Xi-wei,DENG Qi-dong,DONG Rui-shu,et al.1992.Study on strong earthquake activity and risk areas in theShanxi Graben System[J].Seismology and Geology,14(4):305—316(in Chinese).
    杨景春,李有利.2011.活动构造地貌学[M].北京:北京大学出版社.143—153.YANG Jing-chun,LI You-li.2011.Active Tectonic Geomorphology[M].Peking University Press,Beijing.143—153(in Chinese).
    张世民.2000.汾渭地堑系盆地发育进程的差异及其控震作用[J].地质力学学报,6(2):30—37.ZHANG Shi-min.2000.Basin evolutionary differences and seismotectonics of Fenwei Graben System[J].Journal ofGeomechanics,6(2):30—37(in Chinese).
    McC alplin J P.2009.Paleoseismology[M].New York:Acdemic Press.
    Reimer P J,Baillie M G,Bard E,et al.2009.Intcal09 and Marine09 Radiocarbon Age Calibration Curves,0-50,000 Years Cal BP[J].Radiocarbon,51:1111—1150.

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