Late Miocene to recent tectonic evolution of Crete (Greece): Geological observations and model analysis

Using a numerical model, we focus on the late Middle Miocene to Recent kinematic evolution of the Cretan segment of the Hellenic Arc. Geological observations of Crete are given a quantitative interpretation in terms of tectonic mechanisms controlling the evolution of the active arc boundary. This was achieved by calculating intra-plate stress fields for various possible distributions of forces and comparing the models with observations. The models address specific questions concerning important changes in the observed horizontal stress patterns. We deal with the question of what caused extension to initiate. Modelling results of the collapse of an earlier formed topography and extensional forces acting on the plate boundary are compared with a newly reconstructed tectonostratigraphy of Crete. Our results suggest that arc-normal pull is the dominant force that generates the Late Miocene extension in the Cretan segment of the overriding plate, although arc-normal pull in combination with intra-plate spreading forces cannot be excluded. The observed transform motions in the Pliny and Strabo trenches led us to incorporate experiments with additional resistance on the eastern (Levantine) segment of the Hellenic Arc. The models performed with a transform resistance along the trenches are in agreement with the Cretan deformation for the Pliocene to Recent period. The stress fields for the short duration compressional periods around the Middle-Late Miocene and the Miocene-Pliocene boundary are modelled by assuming resistive instead of tensional forces acting at the overriding margin.