Abstract:

Fanchang area is an important segment of the Lower and Middle Yangtze ironcoppergold metallogenic belt, and the ore deposits are evidently controlled by structures. Field investigation and measurement have been carried out on the folds, faults and joints in this area, with determination on the principal stress directions of the multiphase structural activities through deformation characteristics observation and structural set analysis. The directions of the main palaeotectonic stress fields were EW and SN during preIndosinian, NNW during Indosinian, EW during early Yanshanian, NWW during late Yanshanian, NE and EW during Himalayan period. On the basis of the study, an analysis has been completed on the evolution of palaeotectonic stress field in the Fanchang area. Furthermore, it shows that the main tectonic evolution was from Indosinian to late Yanshanian.

Key words:  palaeotectonic stress field, evolution of palaeotectonic stress field, Fanchang area , of Anhui Province