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 kine matic evolution of the Cretan segment of the Hellenic Arc. Geological obser vations of Crete are given a quantitative interpretation in terms of tecton ic mechanisms controlling the evolution of the active arc boundary. This wa s achieved by calculating intra-plate stress fields for various possible di stributions of forces and comparing the models with observations. The model s address specific questions concerning important changes in the observed h orizontal stress patterns. We deal with the question of what caused extensi on to initiate. Modelling results of the collapse of an earlier formed topo graphy and extensional forces acting on the plate boundary are compared wit h a newly reconstructed tectonostratigraphy of Crete. Our results suggest t hat arc-normal pull is the dominant force that generates the Late Miocene e xtension 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 i ncorporate experiments with additional resistance on the eastern (Levantine ) segment of the Hellenic Arc. The models performed with a transform resist ance along the trenches are in agreement with the Cretan deformation for th e Pliocene to Recent period. The stress fields for the short duration compr essional periods around the Middle-Late Miocene and the Miocene-Pliocene bo undary are modelled by assuming resistive instead of tensional forces actin g at the overriding margin. (C) 1998 Elsevier Science B.V. All rights reser ved.