Paleomagnetic constraints on the timing and distribution of Cenozoic rotations in Central and Eastern Anatolia

Abstract

Abstract. To quantitatively reconstruct the kinematic evolution of Central and Eastern Anatolia within the framework of Neotethyan subduction accommodating Africa-Eurasia convergence, we paleomagnetically assess timing and amount of vertical axis rotations across the Ulukışla and Sivas regions. We show paleomagnetic results from ~ 30 localities identifying a coherent rotation of a block – comprising the southern Kırşehir Block, the Ulukışla basin, the Central and Eastern Taurides, and the southern part of the Sivas basin. This block experienced a ~ 30° counter-clockwise vertical axis rotation since Oligocene time. Sediments in the northern Sivas region show clockwise rotations. We use the rotation patterns together with known fault zones to argue that the counter-clockwise rotating domain of south-central Turkey was bounded by the Savcılı Thrust Zone and Deliler-Tecer Fault Zone in the north and by the African-Arabian trench in the south, the western boundary of which is poorly constrained and requires future study. Our new paleomagnetic constraints provide a key ingredient for future kinematic restorations of the Anatolian tectonic collage.

A long-lived Late Cretaceous–early Eocene extensional province in Anatolia? Structural evidence from the Ivriz Detachment, southern central Turkey

“…Combined with our new data, (which unlike the Kır¸se-hir Block have not yet been corrected for post-early Eocene vertical axis rotations, Gürer et al, 2017), this suggests that Central Anatolia was the locus of a major, Late Cretaceous-Paleocene extensional province (Fig. 10) whereby exhumation of units previously underthrusted below oceanic lithosphere occurred in an overriding plate position above an active subduction zone.…”

“…Structural analysis of the Kır¸sehir Block identified several extensional detachments (Gautier et al, 2002;Lefebvre et al, 2011) and retrograde extensional shear zones (Isik et al, 2008). When corrected for Cenozoic vertical axis rotations obtained from granitoids postdating metamorphism (Lefebvre et al, 2013), these data show that extensional exhumation occurred under ∼E-W-directed extension since at least ∼80-75 Ma.…”

“…When corrected for Cenozoic vertical axis rotations obtained from granitoids postdating metamorphism (Lefebvre et al, 2013), these data show that extensional exhumation occurred under ∼E-W-directed extension since at least ∼80-75 Ma. Associated sedimentary basins suggest that E-W-directed extension had ceased by early Eocene time Isik et al, 2014Isik et al, , 2008. The Kır¸sehir Block is presently bound by the major Tuzgölü and Ecemi¸s fault zones in the west and in the east, respectively (Fig.…”

Structure and kinematic evolution of the Southern Sivas Fold-Thrust Belt, Sivas Basin, Central Anatolia, Turkey

“…These analyses focus on the kinematics of strain rather than potential variations through time, the latter being difficult to assess due to sparse constraints on the precise timing of faulting. Paleomagnetic data reveal common verticalaxis rotations of approximately 30° counter-clockwise across the study area, although individual sites show substantial variability, including local clockwise rotations (Gürsoy et al, 1997(Gürsoy et al, , 2011Platzman et al, 1998;Gürer et al, 2018). Because of the uncertainty in whether rotations reflect regional versus local block rotations, we do not incorporate paleomagnetic rotations in our kinematic analyses; however, we recognize that a small amount of mostly clockwise restoration (due to counter-clockwise rotation) may be applied to these data.…”

Palinspastic Reconstruction Versus Cross‐Section Balancing: How Complete Is the Central Taurides Fold‐Thrust Belt (Turkey)?

“…Metamorphic rocks in the Afyon zone are locally covered by Paleocene‐Eocene marine sedimentary rocks (Candan et al, ; Gürer et al, ), which demonstrate rapid exhumation of the metamorphic units. Exhumation was accommodated along extensional detachments in a long‐lived, Late Cretaceous to early Eocene back‐arc basin (Gürer, Plunder, et al, ) that, when corrected for Eocene and younger vertical axis rotations (Lefebvre et al, ; Gürer, van Hinsbergen, et al, ), accommodated E‐W extension.…”