徐州“寨山角砾岩”成因新知

New Discovery about the Origin of Zhaishan Breccia in Xuzhou

徐州“寨山角砾岩”成因新知房友东（徐州煤炭工业学校，徐州，２２１０１１）关键词：角砾岩，海底滑积岩，局限盆地，液体层，江苏徐州。ＮｅｗＤｉｓｃｏｖｅｒｙａｂｏｕｔｔｈｅＯｒｉｇｉｎｏｆＺｈａｉｓｈａｎＢｒｅｃｃｉａｉｎＸｕｚｈｏｕ￥ＦａｎｇＹｏｕｄｏ...

About the origin of Zhaishan Breccia in Xuzhou, there are lots of arguments. The paper chiefly analyses the Ordovician formation in Zhaishan Mt.and studies the section information and then further detects that Zhaishan Breccia in Xuzhou is a complex with many origins. It's mainly the Olistosirome which slipped along the submarine slope, and later was destroyed by the dissolve-collapse.In Xuzhou section,before the Huaiyuan Event, the sedimentary environment was a extent with high energy. At the begining of middle Ordovician, it became limited basin with low energy and sleep slopes.The center of the basin near Qingshanquan. This provided a favorable factor for the downslope movement. Inside the Zhaishan Breccia, there are many rounded gravels which usually gather into spherical grave aggregates. It illustrates that it had been stricken and freed. That is, it had been through removal process. The thickness of Zhaishan Breccia in Zhaishan Mt. and Jianshan Mt. is less than 200m,and that in Qingshanquan between the two areas is more than 400m. It is also the result of the reaction of masswasting. While the CaSO4.2H2O underlying the Xiaoxian Group formation was buried for hundreds meters deep, it would lose the 2H2O and become CaSO4, then the water decreased greatly, thus, the liquid layers formed. So the overlying masswasting will be very easy to appear.