小江断裂带南段全新世活动的地质地貌证据与滑动速率
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摘要
小江断裂带南段位于近SN向的鲜水河-小江断裂系与NW向的红河-哀牢山断裂系的交会地带。在遥感影像上,小江断裂带南段线状特征清楚,且连续分布,表现为1条贯通的、单一的断裂构造,全长约70km,总体走向N20°E左右,中间呈略向E凸出的弧形。在龙潭村两岔河一带,沿着该断裂段存在比较典型的山脊、冲沟同步左旋位错现象。在跨断塞塘开挖的探槽剖面上,断裂分布状况、断错地层的沉积学特征、产状变化以及初步年代测试结果揭示了3次明显断错地表的古地震事件,显示了小江断裂带南段具有重复孕育和发生强震的能力。利用Trimble 5800 GPS实时差分测量系统,对两岔河地区存在典型同步位错特征的2条冲沟及其它们中间的台地进行了精细测量,位错量为(18.3±0.5)m;T_2阶地面是断裂西盘2条冲沟之间及其邻近地带的最高层状地貌面,通过不同深度年代数据的线性回归分析,该地貌面停止接受沉积的时代约为2606a BP。根据地质方法获得了小江断裂带南段全新世左旋走滑速率为(7.02±0.20)mm/a,与利用GPS数据获得的结果有着较好的一致性。对小江断裂带南段活动性和滑动速率的初步研究结果表明,在滇东南地区不存在川滇块体向S或SSE方向滑移被曲江断裂和石屏-建水断裂挤压变形吸收、而使得小江断裂带南段左旋走滑速率大幅度减小的现象,该断裂段是1条活动性明显的全新世断裂。这些初步认识为小江断裂带南段的未来地震危险性评价以及川滇地区的地震构造模型建立和检验提供了可以借鉴的基础地质资料。
The southern segment of the Xiaojiang Fault(SSXF) is located at the intersection of the Xianshuihe-Xiaojiang Fault and Red River-Ailao Shan fault systems in the southeast margin of the Tibetan plateau.Based on the interpretation of remote sensing image,the SSXF clearly shows the linear feature and continuous distribution as a single,penetrating fault.It has a total length of about 70 km,trends generally about 20° to the northeast and protrudes slightly in the middle to the east.A typically geomorphologic phenomenon about the synchronous left-lateral dislocation of ridges and gullies can be found at Liangchahe,Longtan Village along the SSXF.The distribution of faults,the sedimentary features,attitude variance and the primary dating results of the offset strata in the trench section across fault sag ponds reveal three paleoseismic events rupturing obviously the surface,which demonstrates that the SSXF has the ability of recurrence of strong earthquakes.High-precision topographic map about two gullies and the platform between them with synchronous dislocation is acquired by using the Trimble 5800 GPS real-time difference measurement system.The dislocation is(18.3±0.5) m.As the top geomorphologic surface between the above two gullies and their adjacent area,the terrace surface T_2 stopped accepting deposits at ~ 2606 a,based on the linear regression analysis of three dating data.According to the geological method,a sinistral strike-slip rate of(7.02±0.20) mm/a on the SSXF in the Holocene is obtained,which has a good consistency with the results provided by using GPS data.The preliminary results about the Holocene activity and slip rate of the SSXF demonstrate that the southward or south-southeast motion of the Sichuan-Yunnan block in the SE Yunnan region has not been absorbed by the possible shortening deformation and the sinistral strike-slip rate of the SSXF has not been drastically reduced.The SSXF is a Holocene fault with obvious activity.This preliminary understanding provides some basic geological data for the seismic risk evaluation of the SSXF in the future,and for the establishment and inspection of the seismotectonic model about the Sichuan-Yunnan block.
The southern segment of the Xiaojiang Fault(SSXF) is located at the intersection of the Xianshuihe-Xiaojiang Fault and Red River-Ailao Shan fault systems in the southeast margin of the Tibetan plateau.Based on the interpretation of remote sensing image,the SSXF clearly shows the linear feature and continuous distribution as a single,penetrating fault.It has a total length of about 70 km,trends generally about 20° to the northeast and protrudes slightly in the middle to the east.A typically geomorphologic phenomenon about the synchronous left-lateral dislocation of ridges and gullies can be found at Liangchahe,Longtan Village along the SSXF.The distribution of faults,the sedimentary features,attitude variance and the primary dating results of the offset strata in the trench section across fault sag ponds reveal three paleoseismic events rupturing obviously the surface,which demonstrates that the SSXF has the ability of recurrence of strong earthquakes.High-precision topographic map about two gullies and the platform between them with synchronous dislocation is acquired by using the Trimble 5800 GPS real-time difference measurement system.The dislocation is(18.3±0.5) m.As the top geomorphologic surface between the above two gullies and their adjacent area,the terrace surface T_2 stopped accepting deposits at ~ 2606 a,based on the linear regression analysis of three dating data.According to the geological method,a sinistral strike-slip rate of(7.02±0.20) mm/a on the SSXF in the Holocene is obtained,which has a good consistency with the results provided by using GPS data.The preliminary results about the Holocene activity and slip rate of the SSXF demonstrate that the southward or south-southeast motion of the Sichuan-Yunnan block in the SE Yunnan region has not been absorbed by the possible shortening deformation and the sinistral strike-slip rate of the SSXF has not been drastically reduced.The SSXF is a Holocene fault with obvious activity.This preliminary understanding provides some basic geological data for the seismic risk evaluation of the SSXF in the future,and for the establishment and inspection of the seismotectonic model about the Sichuan-Yunnan block.
引文
白志明,王椿镛.2003.云南地区上部地壳结构和地震构造环境的层析成像研究[J].地震学报,25(2):117-127.BAI Zhi-ming,WANG Chun-yong.2003.Tomographic investigation of the upper crustal structure and seismotectonic environments in Yunnan Province[J].Acta Seismologica Sinica,25(2):117-127(in Chinese).
陈立德.1988.1970年1月5日云南省通海7.7级地震[A]//中国震例.北京:地震出版社.57-76.CHEN Li-de.1988.M_s7.7 earthquake on January 5,1970 in Tonghai,Yunnan[A]//Earthquake Cases in China.Seismological Press,Beijing.57-76(in Chinese).
崔效锋,谢富仁,张红艳.2006.川滇地区现代构造应力场分区及动力学意义[J].地震学报,28(5):451-461.CUI Xiao-feng,XIE Fu-ren,ZHANG Hong-yan.2006.Recent tectonic stress field zoning in Sichuan-Yunnan region and its dynamic interest[J].Acta Seismologica Sinica,28(5):451-461(in Chinese).
国家地震局震害防御司.1995.中国历史强震目录(公元前23世纪-公元1911年)[Z].北京:地震出版社.1-514.Department of Earthquake Hazard Prevention,State Seismological Bureau.1995.Catalogue of Chinese Historical Strong Earthquakes(twenty-third Century BC~1911 AD)[Z].Seismological Press,Beijing.1-514(in Chinese).
虢顺民,计凤桔,向宏发,等.2001.红河活动断裂带[M].北京:海洋出版社.89-108.GUO Shun-min,JI Feng-ju,XIANG Hong-fa,et al.2001.Red River Active Fault Zone[M].China Ocean Press,Beijing.89-108(in Chinese).
何宏林,方仲景,李玶.1993.小江断裂带西支断裂南段新活动初探[J].地震研究,16(3):291-298.HE Hong-lin,FANG Zhong-jing,LI Ping.1993.A preliminary approach to the fault activity of southern segment on Xiaojiang west branch fault[J].Journal of Seismological Research,16(3):291-298(in Chinese).
何宏林,李玶,方仲景.1992.滇东南楔形构造区发震构造背景探讨[J].地震地质,14(3):217-226.HE Hong-lin,LI Ping,FANG Zhong-jing.1992.Analysis of seismogenic conditions in the wedge tectonic region of southeast Yunnan Province[J].Seismology and Geology,14(3):217-226(in Chinese).
呼楠,韩竹军.2013.滇东南弧形构造带现今活动性质的地震学研究[J].地震地质,35(1):1-21.doi:10.3969/j.issn.0253-4967.2013.01.001.HU Nan,HAN Zhu-jun.2013.Seismological study on behaviors of present-day movement of arcuate tectonic belt in southeast Yunnan[J].Seismology and Geology,35(1):1-21.
阚荣举,张四昌,晏凤桐,等.1977.中国西南地区现代构造应力场与现代构造活动特征的探讨[J].地球物理学报,20(2):96-109.KAN Rong-ju,ZHANG Si-chang,YAN Feng-tong,et al.1977.Present tectonic stress field and its relation to the characteristics of recent tectonic activity in southwestern China[J].Acta Geophysica Sinica,20(2):96-109(in Chinese).
李玶.1993.鲜水河-小江断裂带[M].北京:地震出版社.1-267.LI-Ping.1993.Xianshuihe-Xiaojiang Fault Belt[M].Seismological Press,Beijing.1-127(in Chinese).
李西,冉勇康,陈立春,等.2016.红河断裂带南段全新世地震活动证据[J].地震地质,38(3):598-604.doi:10.3969/j.issn.0253-4967.2016.03.007.LI Xi,RAN Yong-kang,CHEN Li-chun,et al.2016.The Holocene seismic evidence on southern segment of the Red River fault zone[J].Seismology and Geology,38(3):596-604(in Chinese).
刘祖荫,皇甫岗,金志林.1999.一九七〇年通海地震[M].北京:地震出版社.1-257.LIU Zu-yin,HUANGFU Gang,JIN Zhi-lin.1999.The 1970 Tonghai Earthquake[M].Seismological Press,Beijing.1-257(in Chinese).
宋方敏,汪一鹏,俞维贤,等.1998.小江活动断裂带[M].北京:地震出版社.1-237.SONG Fang-min,WANG Yi-peng,YU Wei-xian,et al.1998.Xiaojiang Active Faults[M].Seismological Press,Beijing.1-237(in Chinese).
王椿镛,朱成男,刘玉权.1978.用地形变资料测定通海地震的地震断层参数[J].地球物理学报,21(3):191-198.WANG Chun-yong,ZHU Cheng-nan,LIU Yu-quan.1978.Determination of earthquake fault parameter for the Tonghai earthquake from ground deformation data[J].Acta Geophysica Sinica,21(3):191-198(in Chinese).
王阎昭,王恩宁,沈正康,等.2008.基于GPS资料约束反演川滇地区主要断裂现今活动速率[J].中国科学(D辑),38(5):582-597.WANG Yan-zhao,WANG En-ning,SHEN Zheng-kang,et al.2008.GPS-constrained inversion of present-day slip rate along major faults of the Sichun-Yunnan region,China[J].Science in China(Ser D),51(9):1267-1283.
闻学泽.1993.小江断裂带的破裂分段与地震潜势概率估计[J].地震学报,15(3):322-330.WEN Xue-ze.1993.Rupture segmentation and assessment of probabilities of seismic potential on the Xiaojiang fault zone[J].Acta Seismologica Sinica,15(3):322-330(in Chinese).
闻学泽,杜方,龙峰,等.2011.小江和曲江-石屏两断裂系统的构造动力学与强震序列的关联性[J].中国科学(D辑),41(5):713-724.WEN Xue-ze,DU Fang,LONG Feng,et al.2011.Tectonic dynamics and correlation of major earthquake sequences of the Xiaojiang and Qujiang-Shiping fault systems,Yunnan,China[J].Science in China(Ser D),54(10):1563-1575.
吴中海,龙长兴,范桃园,等.2015.青藏高原东南缘弧形旋扭活动构造体系及其动力学特征与机制[J].地质通报,34(1):1-31.WU Zhong-hai,LONG Chang-xing,FAN Tao-yuan,et al.2015.The arc rotational-shear active tectonic system on the southeastern margin of Tibetan plateau and its dynamic characteristics and mechanism[J].Geological Bulletin of China,34(1):1-31(in Chinese).
徐锡伟,韩竹军,杨晓平,等.2016.中国及邻区地震构造图[CM].北京:地震出版社.XU Xi-wei,HAN Zhu-jun,YANG Xiao-ping,et al.2016.Seismotectonic Map of China and Its Adjacent Regions[CM].Seismological Press,Beijing(in Chinese).
张俊昌.1979.曲江断裂的新活动与通海地震[J].地震研究,(1):38-43.ZHANG Jun-chang.1979.New activities of Qujiang Fault and Tonghai earthquake[J].Journal of Seismological Research,(1):38-43(in Chinese).
Allen C R,Gillespie A R,Yuan H,et al.1984.Red River and associated faults,Yunnan Province,China:Quaternary geology,slip rates,and seismic hazard[J].The Geology Society America Bulletin,95(6):686-700.
Allmendinger R W,Reilinger R,Loveless J.2007.Strain and rotation rate from GPS in Tibet,Anatolia,and the Altiplano[J].Tectonics,26(3):TC3013.
He H L,Yasutaka I,Song F M,et al.2002.Late Quaternary slip rate of the Xiaojiang Fault and its implication[J].Seismology and Geology,24(1):14-26.
Xiong J G,Li Y L,Zhong Y Z,et al.2016.Paleomagnetism of the Jianshui Basin in Yunnan,SW China,and geomorphological evolution of the Yunnan Plateau since the Neogene[J].Journal of Asian Earth Sciences,123:67-77.
Michel G W,Becker M,Angermann D,et al.2000.Crustal motion in E-and SE-Asia from GPS measurements[J].Earth Planets and Space,52(10):713-720.
Replumaz A,Lacassin R,Tapponnier P,et al.2001.Large river offsets and Plio-Quaternary dextral slip rate on the Red River Fault(Yunnan,China)[J].Journal of Geophysical Research:Solid Earth,106(Bl):819-836.
Schoenbohm L M,Burchfiel B C,Chen L Z.2006.Propagation of surface uplift,lower crustal flow,and Cenozoic tectonics of the southeast margin of the Tibetan plateau[J].Geology,34(10):813-816.
Shen J,Wang Y P,Song F M.2003.Characteristics of the active Xiaojiang fault zone in Yunnan,China:A slip boundary for the southeastward escaping Sichuan-Yunnan block of the Tibetan plateau[J].Journal of Asian Earth Sciences,21(10):1085-1096.
Shen Z K,Lu J N,Wang M,et al.2005.Contemporary crustal deformation around the southeast borderland of the Tibetan plateau[J].Journal of Geophysical Research,110(B11):B11409.
Tapponnier P,Molnar P.1977.Active faulting and tectonics in China[J].Journal of Geophysical Research,82(20):2905-2930.
Wang E,Burchfiel B C,Royden L H,et al.1998.Late Cenozoic Xianshuihe-Xiaojiang,Red River,and Dali fault systems of southwestern Sichuan and central Yunnan,China[J].Special Paper of the Geological Society of America,327:1-108.
Wang Y,Zhang B,Hou J J,et al.2014.Structure and tectonic geomorphology of the Qujiang Fault at the intersection of the Ailao Shan-Red River Fault and the Xianshuihe-Xiaojiang fault system,China[J].Tectonophysics,634:156-170.
Zhang P Z,Shen Z K,Wang M,et al.2004.Continuous deformation of the Tibetan plateau from global positioning system data[J].Geology,32(9):809-812.
陈立德.1988.1970年1月5日云南省通海7.7级地震[A]//中国震例.北京:地震出版社.57-76.CHEN Li-de.1988.M_s7.7 earthquake on January 5,1970 in Tonghai,Yunnan[A]//Earthquake Cases in China.Seismological Press,Beijing.57-76(in Chinese).
崔效锋,谢富仁,张红艳.2006.川滇地区现代构造应力场分区及动力学意义[J].地震学报,28(5):451-461.CUI Xiao-feng,XIE Fu-ren,ZHANG Hong-yan.2006.Recent tectonic stress field zoning in Sichuan-Yunnan region and its dynamic interest[J].Acta Seismologica Sinica,28(5):451-461(in Chinese).
国家地震局震害防御司.1995.中国历史强震目录(公元前23世纪-公元1911年)[Z].北京:地震出版社.1-514.Department of Earthquake Hazard Prevention,State Seismological Bureau.1995.Catalogue of Chinese Historical Strong Earthquakes(twenty-third Century BC~1911 AD)[Z].Seismological Press,Beijing.1-514(in Chinese).
虢顺民,计凤桔,向宏发,等.2001.红河活动断裂带[M].北京:海洋出版社.89-108.GUO Shun-min,JI Feng-ju,XIANG Hong-fa,et al.2001.Red River Active Fault Zone[M].China Ocean Press,Beijing.89-108(in Chinese).
何宏林,方仲景,李玶.1993.小江断裂带西支断裂南段新活动初探[J].地震研究,16(3):291-298.HE Hong-lin,FANG Zhong-jing,LI Ping.1993.A preliminary approach to the fault activity of southern segment on Xiaojiang west branch fault[J].Journal of Seismological Research,16(3):291-298(in Chinese).
何宏林,李玶,方仲景.1992.滇东南楔形构造区发震构造背景探讨[J].地震地质,14(3):217-226.HE Hong-lin,LI Ping,FANG Zhong-jing.1992.Analysis of seismogenic conditions in the wedge tectonic region of southeast Yunnan Province[J].Seismology and Geology,14(3):217-226(in Chinese).
呼楠,韩竹军.2013.滇东南弧形构造带现今活动性质的地震学研究[J].地震地质,35(1):1-21.doi:10.3969/j.issn.0253-4967.2013.01.001.HU Nan,HAN Zhu-jun.2013.Seismological study on behaviors of present-day movement of arcuate tectonic belt in southeast Yunnan[J].Seismology and Geology,35(1):1-21.
阚荣举,张四昌,晏凤桐,等.1977.中国西南地区现代构造应力场与现代构造活动特征的探讨[J].地球物理学报,20(2):96-109.KAN Rong-ju,ZHANG Si-chang,YAN Feng-tong,et al.1977.Present tectonic stress field and its relation to the characteristics of recent tectonic activity in southwestern China[J].Acta Geophysica Sinica,20(2):96-109(in Chinese).
李玶.1993.鲜水河-小江断裂带[M].北京:地震出版社.1-267.LI-Ping.1993.Xianshuihe-Xiaojiang Fault Belt[M].Seismological Press,Beijing.1-127(in Chinese).
李西,冉勇康,陈立春,等.2016.红河断裂带南段全新世地震活动证据[J].地震地质,38(3):598-604.doi:10.3969/j.issn.0253-4967.2016.03.007.LI Xi,RAN Yong-kang,CHEN Li-chun,et al.2016.The Holocene seismic evidence on southern segment of the Red River fault zone[J].Seismology and Geology,38(3):596-604(in Chinese).
刘祖荫,皇甫岗,金志林.1999.一九七〇年通海地震[M].北京:地震出版社.1-257.LIU Zu-yin,HUANGFU Gang,JIN Zhi-lin.1999.The 1970 Tonghai Earthquake[M].Seismological Press,Beijing.1-257(in Chinese).
宋方敏,汪一鹏,俞维贤,等.1998.小江活动断裂带[M].北京:地震出版社.1-237.SONG Fang-min,WANG Yi-peng,YU Wei-xian,et al.1998.Xiaojiang Active Faults[M].Seismological Press,Beijing.1-237(in Chinese).
王椿镛,朱成男,刘玉权.1978.用地形变资料测定通海地震的地震断层参数[J].地球物理学报,21(3):191-198.WANG Chun-yong,ZHU Cheng-nan,LIU Yu-quan.1978.Determination of earthquake fault parameter for the Tonghai earthquake from ground deformation data[J].Acta Geophysica Sinica,21(3):191-198(in Chinese).
王阎昭,王恩宁,沈正康,等.2008.基于GPS资料约束反演川滇地区主要断裂现今活动速率[J].中国科学(D辑),38(5):582-597.WANG Yan-zhao,WANG En-ning,SHEN Zheng-kang,et al.2008.GPS-constrained inversion of present-day slip rate along major faults of the Sichun-Yunnan region,China[J].Science in China(Ser D),51(9):1267-1283.
闻学泽.1993.小江断裂带的破裂分段与地震潜势概率估计[J].地震学报,15(3):322-330.WEN Xue-ze.1993.Rupture segmentation and assessment of probabilities of seismic potential on the Xiaojiang fault zone[J].Acta Seismologica Sinica,15(3):322-330(in Chinese).
闻学泽,杜方,龙峰,等.2011.小江和曲江-石屏两断裂系统的构造动力学与强震序列的关联性[J].中国科学(D辑),41(5):713-724.WEN Xue-ze,DU Fang,LONG Feng,et al.2011.Tectonic dynamics and correlation of major earthquake sequences of the Xiaojiang and Qujiang-Shiping fault systems,Yunnan,China[J].Science in China(Ser D),54(10):1563-1575.
吴中海,龙长兴,范桃园,等.2015.青藏高原东南缘弧形旋扭活动构造体系及其动力学特征与机制[J].地质通报,34(1):1-31.WU Zhong-hai,LONG Chang-xing,FAN Tao-yuan,et al.2015.The arc rotational-shear active tectonic system on the southeastern margin of Tibetan plateau and its dynamic characteristics and mechanism[J].Geological Bulletin of China,34(1):1-31(in Chinese).
徐锡伟,韩竹军,杨晓平,等.2016.中国及邻区地震构造图[CM].北京:地震出版社.XU Xi-wei,HAN Zhu-jun,YANG Xiao-ping,et al.2016.Seismotectonic Map of China and Its Adjacent Regions[CM].Seismological Press,Beijing(in Chinese).
张俊昌.1979.曲江断裂的新活动与通海地震[J].地震研究,(1):38-43.ZHANG Jun-chang.1979.New activities of Qujiang Fault and Tonghai earthquake[J].Journal of Seismological Research,(1):38-43(in Chinese).
Allen C R,Gillespie A R,Yuan H,et al.1984.Red River and associated faults,Yunnan Province,China:Quaternary geology,slip rates,and seismic hazard[J].The Geology Society America Bulletin,95(6):686-700.
Allmendinger R W,Reilinger R,Loveless J.2007.Strain and rotation rate from GPS in Tibet,Anatolia,and the Altiplano[J].Tectonics,26(3):TC3013.
He H L,Yasutaka I,Song F M,et al.2002.Late Quaternary slip rate of the Xiaojiang Fault and its implication[J].Seismology and Geology,24(1):14-26.
Xiong J G,Li Y L,Zhong Y Z,et al.2016.Paleomagnetism of the Jianshui Basin in Yunnan,SW China,and geomorphological evolution of the Yunnan Plateau since the Neogene[J].Journal of Asian Earth Sciences,123:67-77.
Michel G W,Becker M,Angermann D,et al.2000.Crustal motion in E-and SE-Asia from GPS measurements[J].Earth Planets and Space,52(10):713-720.
Replumaz A,Lacassin R,Tapponnier P,et al.2001.Large river offsets and Plio-Quaternary dextral slip rate on the Red River Fault(Yunnan,China)[J].Journal of Geophysical Research:Solid Earth,106(Bl):819-836.
Schoenbohm L M,Burchfiel B C,Chen L Z.2006.Propagation of surface uplift,lower crustal flow,and Cenozoic tectonics of the southeast margin of the Tibetan plateau[J].Geology,34(10):813-816.
Shen J,Wang Y P,Song F M.2003.Characteristics of the active Xiaojiang fault zone in Yunnan,China:A slip boundary for the southeastward escaping Sichuan-Yunnan block of the Tibetan plateau[J].Journal of Asian Earth Sciences,21(10):1085-1096.
Shen Z K,Lu J N,Wang M,et al.2005.Contemporary crustal deformation around the southeast borderland of the Tibetan plateau[J].Journal of Geophysical Research,110(B11):B11409.
Tapponnier P,Molnar P.1977.Active faulting and tectonics in China[J].Journal of Geophysical Research,82(20):2905-2930.
Wang E,Burchfiel B C,Royden L H,et al.1998.Late Cenozoic Xianshuihe-Xiaojiang,Red River,and Dali fault systems of southwestern Sichuan and central Yunnan,China[J].Special Paper of the Geological Society of America,327:1-108.
Wang Y,Zhang B,Hou J J,et al.2014.Structure and tectonic geomorphology of the Qujiang Fault at the intersection of the Ailao Shan-Red River Fault and the Xianshuihe-Xiaojiang fault system,China[J].Tectonophysics,634:156-170.
Zhang P Z,Shen Z K,Wang M,et al.2004.Continuous deformation of the Tibetan plateau from global positioning system data[J].Geology,32(9):809-812.