Publication Date:
2022-08-25
Description:
We review the geodynamic evolution of the Aegean–Anatolia region and discuss strain localisation there over
geological times. From Late Eocene to Present, crustal deformation in the Aegean backarc has localised progressively
during slab retreat. Extension started with the formation of the Rhodope Metamorphic Core Complex
(Eocene) and migrated to the Cyclades and the northern Menderes Massif (Oligocene and Miocene),
accommodated by crustal-scale detachments and a first series of core complexes (MCCs). Extension then
localised in Western Turkey, the Corinth Rift and the external Hellenic arc after Messinian times, while the
North Anatolian Fault penetrated the Aegean Sea. Through time the direction and style of extension have
not changed significantly except in terms of localisation. The contributions of progressive slab retreat and
tearing, basal drag, extrusion tectonics and tectonic inheritance are discussed and we favour a model
(1) where slab retreat is the main driving engine, (2) successive slab tearing episodes are the main causes
of this stepwise strain localisation and (3) the inherited heterogeneity of the crust is a major factor for
localising detachments. The continental crust has an inherited strong heterogeneity and crustal-scale contacts
such as major thrust planes act as weak zones or as zones of contrast of resistance and viscosity that
can localise later deformation. The dynamics of slabs at depth and the asthenospheric flow due to slab retreat
also have influence strain localisation in the upper plate. Successive slab ruptures from the Middle Miocene to
the Late Miocene have isolated a narrow strip of lithosphere, still attached to the African lithosphere below
Crete. The formation of the North Anatolian Fault is partly a consequence of this evolution. The extrusion
of Anatolia and the Aegean extension are partly driven from below (asthenospheric flow) and from above
(extrusion of a lid of rigid crust).
Description:
Published
Description:
1-33
Description:
7T. Struttura della Terra e geodinamica
Description:
JCR Journal
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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