The role of geological structures in fractal dimension of fractures and drainages in Southwestern Lenjan-Isfahan

Fractal analysis of drainages and fractures is a useful tool to determine the maturity structure of a region. With the help of fractal geometry, this study investigates the fractal dimension of drainages and fractures in the southwestern part of Lenjan, and examines the role of geological structures after determining the most active part of region. In order for fractal analysis of fractures and drainages, box-counting method has been used. To achieve this, four parts A, B, C and D of high structural density were first detected in the region, and the fractal dimensions of drainages and fractures were then calculated and compared. Results of fractal analysis of fractures suggest that sector B is the most active part of the region, while fractal analysis of drainages indicates greater tectonic activity in sector A. The larger number of earthquakes and higher density of fractures in sector B, however, could indicate it as the most active part of the study area. Therefore, contradicts in different results obtained from the fractal dimension analysis of fractures and drainages can be explained by the varieties in lithology. The structural studies indicate the existence of a dextral transpression zone in the study area. The dextral transpression zone resulted in uplift of sector B by development of positive flower structures in this part of the region. Therefore, increased tectonic activity in part B is due to formation of positive flower structures and consequent tectonic uplift.