【摘要】 1680年楚雄地震,造成楚雄州和南安州官署、寺庙、桥梁、学堂等重要建筑物几乎破坏殆尽,死亡近3000人。在航片解译的基础上,经仔细的野外调查以及白龙新村、上野马和大石碑3个探槽的开挖,在楚雄盆地西缘发现此次地震形成的地表破坏遗迹,包括地震断层、地震陡坎、地裂缝、砂脉、地震楔等,分布于上野马-尹家咀水库-上三村一线,总长约12km。地震陡坎高度0.6¹.5m,地震断层位错量0.2¹.2m;采集了19个¹⁴C样品进行AMS测年,得到断错的最新地层¹⁴C年龄为590±30a B.P.。据地表破裂规模和云南地区地震实例分析,此次地震的震级应在7级以上,宏观震中位于地表破裂非常集中的上野马-上三村一带。楚雄-南华断裂是川滇菱形块体内部一条重要的活动断裂,以右旋走滑兼逆冲运动为主,全新世有明显的活动迹象。此次地震等震线呈NW向展布并与楚雄-南华断裂走向基本一致,所揭示的地表破裂分布也与极震区相吻合,据此认为,1680年楚雄地震应是楚雄-南华断裂活动所致。更多还原

【Abstract】 The devastating 1680 Chuxiong earthquake has led to a death toll of about 3000 people,and ruined almost all important buildings of Chuxiong and Nan’an regions,such as government official offices,temples,bridges and schools.We have found numerous surface rupture relics on the western margin of the Chuxiong Basin,including earthquake fault traces,fault scarps,ground fissures,sand dykes and earthquake wedges,all distributed along a12km-long belt from Shangyema through Yinjiazui reservoir to Shangsan Village.These findings are based on our geomorphological interpretation of the air photos,detailed field investigation and careful analyses of 3paleoseismological trenches at Bailongxin,Shangyema and Dashibei villages in the study region.Our findings show the coseismic fault scarps are ca.0.6¹.5m high and the faults have displaced vertically strata by ca.0.2¹.2m.19 samples for AMS ¹⁴C dating are collected and the latest ¹⁴C age of displaced strata is 590 ± 30 a B.P.The magnitude of this 1680 earthquake is estimated to be about M7,according to the empirical scaling relations between the earthquake rupture size and magnitudes in Yunnan region.The macro-epicenter is estimated to be located around the Shangyema-Shangsan Village belt.The Chuxiong-Nanhua Fault is one of the major active faults within the Sichuan-Yunnan block,which behaves as a dextral slip with somewhat reverse component.This fault has been interpreted to be active apparently during the Holocene.The isoseismal lines of the 1680 earthquake trend NW,generally parallel with the strike of the Chuxiong-Nanhua Fault,and the distribution of the surface rupture features agree with the magistoseismic area.These observations suggest the 1680 earthquake has been ruptured by the Chuxiong-Nanhua Fault.更多还原