Neogene supradetachment basin development on Crete (Greece) during exhumation of the South Aegean core complex

Abstract

ABSTRACTTertiary extension in the Aegean region has led to extensional detachment faulting, along which metamorphic core complexes were exhumed, among which is the Early to Middle Miocene South Aegean core complex. This paper focuses on the supradetachment basin developed during the final stages of exhumation of the South Aegean core complex along the Cretan detachment, plus the Late Miocene to Pliocene basin development and palaeogeography associated with the southward motion of Crete during the opening of the Aegean arc. For the latter purpose, the sedimentary and palaeobathymetric evolutions of a large number of Middle Miocene to Late Pliocene sequences exposed on Crete, Gavdos and Koufonisi were studied. The supradetachment basin development of Crete is characterised by a break‐up of the hanging wall of the Cretan detachment into extensional klippen and subsequent migration of laterally coexisting sedimentary systems, and finally the deformation of the exhumed core complex by processes related to the opening of the Aegean arc. Hence, three main tectonic phases are recognised: (1) Early to Middle Miocene N–S extension formed during the Cretan detachment, exhumed in the South Aegean core complex. The Cretan detachment remained active until 11–10 Ma, based on the oldest sediments that unconformably overlie the metamorphic rocks. Successions older than 11–10 Ma unconformably overlie only the hanging wall of the Cretan detachment, and do not contain fragments of the footwall rocks; they therefore predate the oldest exposure of the metamorphic rocks of the footwall. The hanging wall rocks and Middle Miocene sediments form isolated blocks on top of the exhumed metamorphic rocks, which are interpreted as extensional klippen. (2) From approximately 10 Ma onward, southward migration of the area that presently covers Crete was accompanied by E–W extension, and the opening of the Sea of Crete to the north. Contemporaneously, large folds with WNW–ESE striking, NNE dipping axial planes developed, possibly in response to sinistral transpression. (3) During the Pliocene, Crete emerged and tilted to the NNW, probably as a result of left‐lateral transpression in the Hellenic fore‐arc, induced by the collision with the African promontory.