吉黑造山带与华北地台开原—山城镇段构造边界位置

Location of structural boundary between Ji-Hei orogenic zone and Kaiyuan-Shanchen Town section of North China Platform

吉黑造山带与华北地台龙岗-清原地块的构造边界，在“伊舒”和“敦密”断裂带之间的辽北开原-吉南山城镇区段，长期存在不同认识。依据上肥地剖面原定“清河镇群”“北大沟组”和“吴家堡子组”新获岩浆结晶锆石离子探针（SHRIMP）年龄（2497±27）Ma和（2522±15）Ma及杨木林子附近原定“白砬子组”条带状大理岩（结晶灰岩）新发现的微古植物化石Stictosphaeridium tortutosum，Synsphaerium sp．，Histrisphaeridium sp．等（大体时限为震旦纪680～540Ma），结合前人的研究成果，确认清河（清河镇-山城镇）断裂带之南为太古代基底广泛出露的华北地台区，其上残留有稳定、次稳定型沉积组成的古元古代构造-岩石地层；其北为震旦纪、早寒武世及少量晚二叠世活动型沉积的造山带构造-岩石地层。证明清河镇-山城镇断裂带为该区段吉黑造山带与华北地台的边界。

It has been controversial for a long time on the structural boundary between the Ji -Hei orogenic zone and Longgang Qingyuan terrain of the North China Platform, located at the Kaiyuan City of northern Liaoning and Shancheng Town of southern Jilin, the interval of ＂Yi -Shu＂ and ＂Dun-Mi＂ faults. According to the new dating of SHRIMP （2 497 ± 27） Ma and （2 522 ± 15） Ma in the ＂Beidagou Formation＂ and ＂Wujiapuzi Formation＂ of the ＂Qinghezhen Group＂ in the section of Shangfeidi, and the Sinian （680-540 Ma） micro -fossils Stictosphaeridium tortutosum, Synsphaerium sp, Histrisphaeridium sp. newly found from the crystalline limestone of ＂Bailazi Formation＂ near the Yangmulinzi, and referring the previous studies, the authors considered that North China Platform with widely outcropped Archaean basement is located in the south of Qinghe fault, with remains of the Early Proterozoic structure -strata on the top, composed of stabilization sub - stabilization sediment; While in the north of Qinghe fault there is the Ji -Hei orogenic zone deposited with Sinian, Lower Cambrian and a few Upper Permian, belonging to some active sediment of orogenic zone. It demonstrates that the Qinghe Town-Shancheng Town fault is the boundary between the Ji -Hei orogenic zone and North China Platform in this section.