EARTH AND SPACE SCIENCE, cilt.1, ss.1-35, 2020 (SCI-Expanded)
Convergence
between the Eurasian and the African plates in the West Anatolian-Aegean region
results in a trench retreat due to slab roll-back and tearing of the subducted African
lithosphere. The upper plate response of this process gave way to back-arc extension
in the region. In this context, we have conducted a very rigorous AMS study on the
Neogene units in SW Anatolia to unravel the style and amounts of deformation. For
this purpose, from 83 sites in 11 structurally homogeneous domains, 1680 paleomagnetic
samples were analyzed. Obtained results are used to determine principal strain directions
to unravel overall deformation styles and amounts in the region.
The results
have shown that AMS is related to the tectonic deformation, which facilitated that
the AMS directions correspond to cumulative principal strains. Maximum susceptibility
is parallel to the major extension (kmax), minimum susceptibility (kmin) corresponds to compaction after deposition, almost always normal
to the bedding plane. The intermediate axis (kint) found to be parallel to a second extension direction that the
region has been under the control of multi-directional extension during Neogene.
Two mean anisotropy directions
are identified. These are Oligocene-Middle Miocene NW-SE, and Late Miocene-Pliocene
NE-SW directed extension. The mean anisotropy directions are generally parallel
or perpendicular to the general strikes of the normal faults. The results have shown
that the deformation in the region resembles to differentially stretched rubber
sheet under the influence of SW directed
extension exerted by the southwards retreating Eastern Mediterranean subduction
system.