Inherited structural controls on normal fault architecture in the Gulf of Corinth (Greece)

Abstract

In the Gulf of Corinth, E‐W active normal faults and Pleistocene sedimentary basins are segmented along strike by a NNW‐SSE culmination of the Hellenic thrust belt (Zarouchla culmination, ZC), which separates the Derveni‐Corinth basin to the east from the Aigion basin to the west. The eastern zone is characterized by active faults with larger dimensions, cumulative throw and extension, and thicker Plio‐Pleistocene clastic sequences. This distinct geometry is interpreted in terms of greater depths of penetration of the faults to the east, in agreement with earthquake depth distribution. Exhumation of deep imbricates, strong uplift, and NNW‐SSE trends are consistent with ZC being the expression of upper crustal doming, consequent on NNE to NE Miocene extensional stretching, superposed onto the thrust belt. This deformed substratum, strongly oblique to the Pleistocene normal faults, acts as a geometric and mechanical barrier controlling fault segmentation to depths of ∼10 km. The Corinth rift is still in its early phases of opening, and the architecture of a continental crust that is strongly heterogeneous vertically and laterally interferes with processes of growth and linkage of the evolving active normal faults plus their associated sedimentary basins.