Structural properties and tectonic signi ficance of a shear zone discovered within the Tauride orogen near Alanya, SW Turkey

Year 2019, , 31 - 47, 25.04.2019

Volkan Özaksoy

https://doi.org/10.19111/bulletinofmre.502054

Abstract

A major shear zone,
referred to as the Yeşilöz Shear Zone, was discovered in the lower Mahmutlar Nappe
of the Alanya Nappe Complex in Alanya region. The nappe shows early transposed folds
with axial metamorphic foliation and upright open folds formed during
emplacement. The NW-trending shear zone is around 2 km wide and mappable over a
length segment of 10 km. The shear zone consists of the metamorphic rocks of the
host nappe, but with the phyllite mylonitized by vertical shear foliation and the
quartzite and marble dispersed as lenticular bodies. These brittle rock bodies show
broken upright folds similar as in the nappe, and also the phyllite shear lenses
bear relics of the nappe metamorphic foliation. Analysis of kinematic indices in
the shear zone points to a dextral transcurrent deformation. The emplacement of
Mahmutlar Nappe caused mild metamorphism of the upper part of underlying nappe and
also affected it with the development of the shear zone that extended downwards.
The nappe underwent no further translational movement during and after the shear
zone formation, which suggests that the ductile transcurrent deformation probably
accommodated a residual shortening induced by the emplacement of the next, younger
nappe of the Alanya Nappe Complex.

Keywords

folds, foliation, transcurrent shear, kinematic indices, tectonic mèlange, Nappe

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