Date Presented:

Abstract:

The island of Crete represents a portion of the forearc above the northward-dipping Hellenic subduction zone. Crete’s subaerial exposure offers the opportunity to study deformation processes in the forearc area of the rapidly subducting African plate towards the North underneath Eurasia.
The examination of river incision patterns and the distribution of morphological discontinuities based on high-resolution digital topographic datasets yields abundant indicators of recent tectonic activity and deformation. The results from the processing of tectonic geomorphology indices (SL, AF, Ksn etc.) leads to the conclusion that the mid-Miocene E-W trending Messara basin in Central Crete is still evolving in the hanging wall of the Southern Crete extensional detachment fault. Several maps generated in a GIS environment display the spatial distribution of tectonic geomorphology indices, and the combination of them clearly points out the contemporary extensional tectonic regime intercalated with transtensional zones trending N-S, normal to the Messara development, which is in agreement with a general pull-apart basin pattern. The tectonic activity is confirmed by the latest seismic excitation, including the recent shallow (~12km depth) strong seismic events that took place the last two years (Arkalochori on Sept.2021, Mires on May 2023), the epicentres of which are located within the Messara basin area, and south of the south-dipping detachment fault trace. The history of the supra-detachment basin started during Middle Miocene, shortly after the compressional phase of the alpine units’ nappe stacking at the southern part of the Hellenic Arc system. The continuous subsidence of its hanging wall provided accommodation space for an individual Messara basin trending E-W. The rearrangement movements of several fault blocks that bound it are clearly imprinted on the tectonic geomorphology indices’ values, presented in this work.