A new method for simulation of elliptic marker movements and deformation in ductile shear zones

The existence of the elliptic markers such as gravels and porphyroclasts in ductile shear zones is an important strain symbol in the study of kinematics and dynamics in the shear zone. The directions of shear zone movements are estimated and the characteristics of kinematics and rheology are discussed though the observation of field outcrop in combination with experimental petrology in traditional elliptic marker researches. With the introduction and promotion of numerical simulation techniques such as Ansys, Matlab and Mathcad in ductile shear zones, many researchers in China have tried to recover the elliptic marker movement trajectory and deformation characteristics, and achieved remarkable results. However, methods for simulation of elliptic marker movements as well as quantitative and simulative researches on ductile shear zones have been scarcely mentioned in domestic literature. Therefore, on the basis of the latest researches on elliptic marker deformation in ductile shear zones, the paper presents the ideas and methods of numerical simulation in details based on Jeffery and Eshelby’s theory. In addition, the authors have simulated the rotating track and deformation characteristics of elliptic markers under given conditions by using Mathcad software.