伊通-舒兰断裂带四平段14C定年及构造意义

在区域地质构造调查、地球物理资料和遥感解译基础上，采用钻探、槽探、¹⁴C年代学测试等方法，对伊通-舒兰断裂带四平段NE向隐伏断层的时代、性质及构造意义进行探讨。结果表明：1）四平段断裂主要发育于上更新统长英质（含角砾）砂岩层内部，为逆冲推覆断层；2）槽探与钻孔揭露的耕土层、粘土层、泥质砂岩层和长英质（含角砾）砂岩层AMS¹⁴C测年结果分别为－70~6 270 BP、60~7 780 BP、110~21 780 BP和11 740~26 100 BP，断层活动年代总体应归属为前第四纪（＞26 100 BP）；3）结合区域岩浆构造与地震事件可知，本次揭露的NE向隐伏断裂带可能形成于晚更新世。

14C Dating and Tectonic Significance of Siping Section of Yitong-Shulan Fault Zone

Based on the regional geological structure survey, geophysical data and remote sensing interpretation, using drilling, trenching and ¹⁴C chronology, we discuss and study the age, character and tectonic significance of the NE trending buried fault in Siping section of Yitong-Shulan fault zone. The results show that: 1) Siping section is mainly developed in the upper pleistocene felsic(including breccia) sand layer, and belongs to thrust nappe fault; 2) AMS¹⁴C dating results of arable soil layer, clay layer, argillaceous sandstone layer and felsic(including breccia) sandstone layer exposed by trenching and drilling are －70~6 270 BP、60~7 780 BP、110~21 780 BP、11 740~26 100 BP, respectively. The age of fault activity should belong to pre Quaternary (>26 100 BP); 3) Combined with regional magmatic tectonic and seismic events, the NE trending concealed fault zone exposed in this study may have been formed in the late Pleistocene.