江苏大地构造的几个问题

On Three Tectonic Questins in Jiangsu Province

江苏大地构造的几个问题孙竟雄江苏省地质矿产调查研究所，南京，２１１１３５ＯｎＴｈｒｅｅＴｅｃｔｏｎｉｃＱｕｅｓｔｉｎｓｉｎＪｉａｎｇｓｕＰｒｏｖｉｎｃｅ￥ＳｕｎＪｉｎｇｘｉｏｎｇＡｂｓｔｒａｃｔ：Ｔｈｒｅｅｑｕｅｓｔｉｏｎｓｈａｄｂｅｅｎｄｉｓｃｕｓ...

Three questions had been discussed in the paper. The first is whether the Jiaonan-Xiangshui fault is the boundary between North-China Paraplatform and Yangtze Paraplatform. The Yuntai formation of Haizhou group in the north of the fault and Zhangbalin group in the south of the fault belong to a complete suit of metamorphic rock of which the lithological , deformational and metamorphism are basically similar. The seismic survey shows that the fault is located in the upper crust whereas the Xuyi-Huaiying fault is a deep fault cutting into upper mantle. So the fault can not be considered as the above mentioned boundary.Secondly, what is the tectonic belonging of Subei-Jianonan metamorphic block. The paper compared the Subei-Jiaonan metamorphic lock with Dabie block in Anhui province in several aspects,such as low temperature-high pressure blueschist belt , metamorphic phosphate mineral layer,unconformale surface and upper-lower metamorphic strata , ecologite characters and important regional metamorphism. Then, Subei-Jiaonan block is the eastern extending part of Qinlin orogenic belt.Third question is about the location aud geological significance of Jiangnan fault in Jiangsu province. The paper considers that there does not exist big difference in stratigraphic features in the two sides of fault. Gravity survey and magnetic survey show that the Jintan-Ruguo fault may be the part the Jiangnan fault located in Jiangsu. Therefore, it could be the tectonic boundary within the platform , but not the first grade tectonic boundary.