Characteristics of magnetic fabrics of Jiangshan-Shaoxing collision belt and its tectonic implications

The study of anisotropy of magnetic susceptibility (AMS) of rocks from the northern part of Jiangshan-Shaoxing collisional belt demonstrates that the minimum principal AMS axes are the most concentrated one in various types of rocks. The planar projection of the minimum axis shows that the main compressive stress lies on northwest 30°–60°, which trends dominantly in northwest-southeast of Chencai area and arc-like disperse towards both north and south of Chencai. The inclination of the minimum axis illustrates that the Huaxia block is moving northwesterly. Although the maximum axes show slightly dispersal, they are within the confidential circle. The maximum axis intersects with the lineation with a small angle, suggesting that the Jiangshan-Shaoxing collision belt be of a sinistral shear slip. By comparison with magnetic fabrics of various rocks, intensive collision of the Jiangshan-Shaoxing belt was in Late Triassic and sustained to the late Yanshanian period in the form of sinistral shear slip.