The Anatolian Diagonal: a broad left lateral shear zone between the North Anatolian Fault Zone and the Aegean / Cyprus Arcs

Abstract

Recent detailed examination of the internal deformation of the Turkish-Iranian Plateau in the hinterland of Bitlis-Zagros Suture Zone, which is related to the collision of the Arabian and Eurasian plates, indicates multiple intersection points between the right- and left-lateral strike-slip structures explained by an inevitably broad left-lateral strike-slip shear zone, the Anatolian Diagonal. The faults bounding and internally deforming the Anatolian Diagonal were closely examined by using high-resolution satellite images, focal mechanism solutions of the earthquakes, and published seismic reflection data in the offshore areas. The Anatolian Diagonal is a NE-SW trending left-lateral shear zone having a 170 km width between the Central Anatolian and the East Anatolian fault zones and an 850 km length between Erzincan and the Cyprus Arc. It has at least four intersection points with the right-lateral North Anatolian Fault Zone and the Southeast Anatolian-Zagros Fault Zone. As the offshore continuation of the Ecemiş-Deliler Fault of the Anatolian Diagonal, the Biruni Fault reaches the Cyprus Arc and Piri Reis (Mediterranean) Ridge Front west of Cyprus. This structure creates a restraining stepover with the left-lateral Antalya-Kekova Fault Zone and causes NW-SE trending thrusts of the Florence Rise and Antalya Thrust in the Antalya Basin. There is another restraining stepover between the Antalya-Kekova Fault Zone and the Pliny-Strabo Fault Zone, where the thrust-controlled northern margin of Rhodes basin developed. In this neotectonic framework, there is no need for the existence of the highly-debated left-lateral Fethiye-Burdur Fault Zone as an onshore continuation of the Pliny and Strabo faults. In fact, the westerly motion of the Anatolian plate is accommodated by the left-lateral Anatolian Diagonal Shear Zone, Antalya-Kekova Fault Zone and Pliny-Strabo Fault Zone together with the right-lateral North Anatolian Fault Zone.