New kinematic and geochronologic evidence for the Quaternary evolution of the Central Anatolian fault zone (CAFZ)

Abstract

As the kinematics of active faults that bound the Anatolian plate are well studied, it is now essential to improve our understanding of the style and rates of intraplate deformation to constrain regional strain partitioning and improve seismic risk assessments. One of these internal structures, the Central Anatolian fault zone (CAFZ), was originally defined as a regionally significant left-lateral "tectonic escape" structure, stretching for 700 km in a NE direction across the Anatolian plate. We provide new structural, geomorphic, and geochronologic data for several key segments within the central part of the CAFZ that suggest that the sinistral motion has been overstated. The Ecemiş fault, the southernmost part of the CAFZ, has a late-Quaternary minimum slip rate of 1.1 ± 0.4 mm a À1 , slower than originally proposed. Farther north, the Erciyes fault has fed a linear array of monogenetic vents of the Erciyes stratovolcano and 40 Ar/ 39 Ar dating shows a syneruptive stress field of ESE-WNW extension from 580 ± 130 ka to 210 ± 180 ka. In the Erciyes basin, and central part of the CAFZ, we mapped and recharacterized the Erkilet and Gesi faults as predominantly extensional. These long-term geological rates support recent GPS observations that reveal ESE-WNW extension, which we propose as the driver of faulting since 2.73 ± 0.08 Ma. The slip rates and kinematics derived in this study are not typical of an "escape tectonic" structure. The CAFZ is a transtensional fault system that reactivates paleotectonic structures and accommodates E-W extension associated with the westward movement of Anatolia.

Shallow melting of MORB‐like mantle under hot continental lithosphere, Central Anatolia

“…[]. White lines represent vent alignments identified by Higgins [] and Toprak []; distinctly different dates of activity characterize several of these. A NNE‐trending swath of vents through the center of the Egrikuyu field hosts some of the youngest cones in that field.…”

“…The sporadic nature and small volume of Hasan Monogenetic Cluster volcanism [Uslular et al, 2015], coupled with its occurrence in a tectonic basin, suggests that the volcanic activity is tectonically controlled [Valentine and Perry, 2007]. Volcanic vents tend to be distributed along alignments [Toprak, 1998;Higgins, 2014;Uslular et al, 2015] that share orientation with adjacent stratovolcanoes and structures ( Figure 2) and appear to be controlled by fault systems. Magmas apparently ascended along the same lineaments multiple times: several of the older (>0.9 Ma) Hasan Monogenetic Cluster vents are on alignments that were subsequently active in the middle Pleistocene.…”

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

“…To the south, lower Miocene sediments in the Adana Basin (A in Fig. 1) seal the strike-slip component of the Ecemiş Fault Zone, which after the early Miocene time only experienced E-W-directed normal faulting with only a minor strike-slip component (Alan et al, 2011;Higgins et al, 2015;Jaffey and Robertson, 2001;Sarıkaya et al, 2015).…”

“…1 and 3). This fault zone consists of a series of thrusts and towards the west connects to the EFZ through a series of NE-SW-striking sinistral strike-slip faults (Higgins et al, 2015;Fig. 3).…”

Rotations of Normal Fault Blocks Quantify Extension in the Central Tauride Intramontane Basins, SW Turkey

“…Major rotations and associated shortening occurred largely in the Oligocene to perhaps earliest Miocene (Advokaat et al, ; Gülyüz et al, ; Gürer et al, , ; Işık et al, ). Some Pliocene E‐W extension is accommodated to the east of the CTIB, in the Tuz Gölü basin (Fernandez‐Blanco et al, ) and along the Ecemis fault (Higgins et al, ; Jaffey & Robertson, ), but documented displacements are small. We therefore assume that the region to the east of the CTIB did not experience major deformation in the last 20 Myr and evaluate this assumption later in the light of our discussion.…”