太原盆地田庄断裂东段探测和活动性初步研究*

(1.山西省地震局,山西 太原 030002; 2.太原大陆裂谷动力学国家野外科学观测研究站,山西 太原 030025; 3.北京美辰建筑抗震工程有限公司,北京 100021)

田庄断裂; 地质调查; 浅层地震勘探; 空间位置; 断裂活动性

Preliminary Study on Exploration and Activity of East Segment of Tianzhuang Fault in Taiyuan Basin
ZENG Jinyan1,2, LI Zihong1,2, CHEN Wen3, HU Guirang1,2, LIU Yanchun1,2

(1.Earthquake Administration of Shanxi Province, Taiyuan 030021, Shanxi, China)(2.National Continental Rift Valley Dynamic Observatory of Taiyuan, Taiyuan 030025, Shanxi, China)(3.Mei Chen Building Seismic Engineering Limited Liability Company of Beijing,Beijing 100029, China)

Tianzhuang Fault; geological survey; shallow seismic exploration; spatial position; fault activity

备注

田庄断裂为太原盆地内一条较大的隐伏断裂,采用地质调查、浅层地震勘探等方法对该断裂东段(西温庄—滨河东路)开展研究。地质调查结果显示:田庄断裂对太原断陷盆地的地貌形态有明显的控制作用,并且控制着太原盆地的沉降; 浅层地震勘探结果揭示:该断裂空间位置比原来认定的位置向北偏移了约250~600 m,并且在其上盘发育有与主断裂倾向相反的次级断裂。结合TZ2测线北侧附近“太原市活断层探测与地震危险性分析”项目中小店区钻孔联合剖面地层测年资料,认为该断裂错断了上更新统下部地层,并且上断点埋深有向浅部延展的趋势,初步认为田庄断裂的最新活动时代为晚更新世。

Tianzhuang Fault is a large buried fault in Taiyuan Basin and its east segment(from Xiwenzhuang to Riverside east Road)is studied through geological survey and shallow seismic exploration methods. The geological survey results shows that Tianzhuang Fault had the significant control on the landform of Taiyuan basin and the sedimentation of Taiyuan basin. The shallow seismic exploration results reveals that the spatial location of the fault had a northward shift about 250~600 m than the original location, and the secondary fault with contrary dip direction to main fault formed in the upper side of the fault. Combined with the stratigraphic dating data of drilling combined whit the section of the project “Taiyuan Active Fault Detection and Seismic Hazard Analysis” around the north side of the survey line TZ2 in Xiaodian area, we considered that the fault dislocated the lower strata of the upper Pleistocene series, and the depth of the upper breakpoint had a trend of extending to the shallow. We preliminary think that the latest activity era of Tianzhuang Fault is late Pleistocene.