The Tectonic Characteristics And Original Analysis Of Mufu Mountain And Its Surrounding Areas

Mufu-Jiuling mountain is located in the middle of Yangtze plate. There are three styles of folds since Sinian to Triassic. NE folds formed early were modified by the nearly SE folds, the original reason of disharmonic folds mainly due to the differences of mechanical properties of rock mass. The the composition of up-tectonic layer are thin carbonaceous limestone and thin siliceous limestone, which have obvious brittle property and easy-bending. The bottom layer of thick-medium thick carbonate which formed gently folds has the obvious plastic property. The weak rock mass of Devonian and Silurian in the middle play the role in adjusting the unequal shorten length. According to the method of balanced cross-section the shorten length between up and bottom layers in Nantan Lake part of Luotian-Xiushui section is 17.15km, the up-layer got the 27.3% rate of shortening, while the bottom layer got the 6.69% rate of shortening.Based upon FLAC simulation, when the deformation rate is 0.05m/s, the deformation is coincide with Huangshi city; when the rate is lower than 0.005m/s, all the structural layers show the style of complex fold on large scale, and the deformation degree of upper layer is slightly strong, which are coincide with the Jiuling mountain. After that, the study area is likely to be gone through three major tectonic phase before the formation of such disharmonic folds: the initial rapid extrusion, the deformation of the mid-back and low-speed extrusion late.