K. Gessner et al., Tectonic significance of deformation patterns in granitoid rocks of the Menderes nappes, Anatolide belt, southwest Turkey, INT J E SCI, 89(4), 2001, pp. 766-780
Deformation fabrics in Proterozoic/Cambrian granitic rocks of the Cine napp
e, and mid-Triassic granites of the Bozdag nappe constrain aspects of the t
ectonometamorphic evolution of the Menderes nappes of southwest Turkey. Bas
ed on intrusive contacts and structural criteria, the Proterozoic/Cambrian
granitic rocks of the Cine nappe are subdivided into older orthogneisses an
d younger metagranites. The deformation history of the granitic rocks docum
ents two major deformation events. An early, pre-Alpine deformation event (
DPA) during amphibolite-facies metamorphism affected only the orthogneisses
and produced predominantly top-to-NE shear-sense indicators associated wit
h a NE-trending stretching lineation. The younger metagranites are deformed
both by isolated shear zones, and by a major shear zone along the southern
boundary of the Cine submassif. We refer to this Alpine deformation event
as D-A3. D-A3 shear zones are associated with a N-trending stretching linea
tion, which formed during greenschistfacies metamorphism. Kinematic indicat
ors associated with this stretching lineation reveal a top-to-south sense o
f shear. The greenschist-facies shear zones cut the amphibolite-facies stru
ctures in the orthogneisses. Pb-207/Pb-206 dating of magmatic zircons from
a metagranite, which crosscuts orthogneiss containing amphibolite-facies to
p-to-NE shear-sense indicators, shows that D-PA occurred before 547.2 +/-1.
0 Ma. Such an age is corroborated by the observation that mid-Triassic gran
ites of the Cine and Bozdag nappes lack D-PA structures. The younger, top-t
o-south fabrics formed most likely as a result of top-to-south Alpine nappe
stacking during the collision of the Sakarya continent with Anatolia in th
e Eocene.