Studying in Middle-Tectonic level and Rock Deformation Characteristic in Longshoushan Area

The kinematic and dynamic characteristics of Longshoushan ductile shear zone in the early period of Caledonian orogeny was mainly the bottom-up tensile stress. In the middle period, it was largely dextral pure shearing action which was NW-SE trend. In the last period, it was the positive pressure of NE-SW trend accompanied by local press twist action. At the same time, the maximum principal stress of the dextral pure shearing action is NW-SE trend. The principal stress in the last period was NE-SW trend. According to the distribution of the ductile shear zone in the strata, namely only in Jixianian System and Sinian System, we can conclude that the ductile shear zone should be formed after Sinian Period. As we all know, the Caledonian orogeny was from the end of Sinian Period to the end of Silurian Period, so it was the tectonic movement that resulted in the formation of the ductile shear zone in the studied area. In addition, it added layer upon layer at different stages. Combined with the age of Jinchuan ultrabasic complex, we can conclude that the ductile shear zone has no contribution to Jinchuan deposit, but maybe it can help the ultrabasic complex move to shallow zone. With the diameter of the subgrain of quartz, we can estimate that its paleostress D-value was 282.9MPa.