Pleistocene-Recent deformation regime of the Eastern Hellenic forearc inferred from multiscale fault-kinematic analysis, Island of Rhodes, Greece

Abstract

The Island of Rhodes constitutes an exhumed portion of the Eastern Hellenic forearc and, thus, lends itself to investigating upper plate deformation kinematics of oblique subduction. Much of the east coast of the island features prominent marine terraces carved into Cretaceous carbonate rocks and decorated by Pleistocene marine deposits. The terraces are displaced by kilometer-scale faults, which are part of an island-wide pattern of linear morphological discontinuities, the kinematics of which are unknown. The generation of a UAV-based high-resolution digital surface model of a coastal hill slope near the town of Archangelos allowed us to quantify the horizontal and vertical components of fault displacements. The hill slope counts 17 marine terraces, serving as ideal kinematic marker surfaces, that are displaced by a set of three NNE-striking continental margin-parallel faults. Slip vectors inferred from the displacement components indicate oblique normal sense-of-displacement on the faults on the order of tens of meters. Interestingly, displacement magnitudes increase with elevation and age of the terraces, thus, the results point to normal faulting during rock uplift (exhumation) and approximately 400m of rock uplift. Kinematic analysis of nearby small-scale brittle shear faults (slickensides) in Plio-Pleistocene marine deposits indicate an overall NE-SW extension, in agreement with the kinematics of the kilometer-scale faults cutting the marine terraces. Therefore, we conclude that tectonics of the Eastern Hellenic forearc throughout Plio-Pleistocene around the island of Rhodes is characterized by rock uplift during distributed margin-parallel left-lateral shear.