Analysis on mechanism of geosuture in Henglin area,Changzhou City,Jiangsu Province

The geosutures in Henglin area, Changzhou City, Jiangsu Province were started in 1989 and were the earliest geosutures discovered in the Su-Xi-Chang areas. The geosutures are generally along the NE strike, with a drop of 100～500 mm and a width of 50～350 m. The distribution and strike of local geosutures are controlled by the ancient buried hill, geosutures are mainly developed in the edge of the ancient buried hill and the contact zone between sand layer and karst. In terms of time, their development is corresponding to the stage when the water level of the main underground mining layer decreases faster and the karst water level is lower than the second confined water. Based on the comprehensive analysis, it is concluded that the cracks in the transverse woodland are caused by the excessive exploitation of groundwater, the uneven settlement caused by bedrock undulation, and the karst soil caves, which have the characteristics of karst collapse and bedrock buried hill.