Structural analyses of Şaphane relay ramps and fault linkage evolution in active extensional regime, western Turkey

The Şaphane relay ramps (SAR-I and SAR-II) are well-developed structures formed by extensional tectonic settings in western Turkey. Their formation is controlled by the configuration of 2 different breaching faults located in between and the overlapping area of 3 normal faults, which are the Şaphane, Gurlek, and Yumrutas faults. The relay ramps form within a ~3 km-wide and ~12 km-long interaction zone between 045° and 060° trending faults on the northern boundary of the Erdogmus-Yenigediz graben. Some variations in structural styles and its products (for example, overlapping slip-lines (slickenlines), fractures, and antithetic-synthetic faults) are observed along the breaching faults in the relay ramps that were probably created during the formation of the relay structures. In this research, field data from these segmented normal faults having displacement and an interaction area are presented. This normal faulting that resulted from the recent extensional tectonic regime is related to the whole crustal deformation in western Turkey, and the progressive stages have created such a characteristic structure, the relay ramp.