EGE VE KIBRIS TEKTONİK YAYLARININ NEOTEKTONİK KESİŞİMİ: ISPARTA AÇISI, GB TÜRKİYE’DE GENİŞLEME VE DOĞRULTU ATIMLI FAYLANMA

Abstract

The Isparta Angle and adjacent Antalya Bay areas constitute an important segment of the eastern Mediterranean region, located at the intersection of the southwardconvex Aegean and Cyprus arcs. Some recent tectonic maps show the Isparta Angle as a NW–SE compressional lineament extending eastwards into the Kyrenia Range of northern Cyprus. However, fault data from the onshore Isparta Angle, together with offshore shallow seismic reflection data, show that the present morphotectonic setting is dominated by extension. The last phase of compression to affect the area studied in the Late Miocene, was accompanied by regional nappe emplacement (Lycian Nappes). Onshore, fault planes, measured from fault zones bounding both the limbs and the core of the Isparta Angle are oriented predominantly NE–SW, NW–SE and N–S. Superimposed slickenfibres show that reverse faults were succeeded, in turn, by right-lateral faults, then by normal faults. The fault phases are dated by stratigraphical and geomorphological evidence. Reverse faults date from the Late Miocene, or earlier compressional deformation, whereas the right-lateral faults mainly developed during latest Miocene–Early Pliocene. Normal faulting dominated from the Late Pliocene–Recent. An interpretation of shallow seismic reflection data shows that Antalya Bay is characterised by a NW–SE-trending asymmetrical graben system that has continued to be active. During the Late Miocene–Early Pliocene right-lateral strike-slip resulted from shear along the eastern termination of a zone of extension and rotation that characterises the western Aegean. This shear was focused in a N–S direction by inherited zones of structural weakness in the basement (Antalya Complex). The switch to NE–SW extension in the Late Pliocene–Quaternary relates to a regional change in stress direction throughout the Aegean region and was accompanied by strong uplift of the Bey Daˇglari region of the Taurus Mountains, bordering the Isparta Angle in the west. The Isparta Angle is the link between: (a) the extensional province of western Turkey bounded to the south by the actively subducting Hellenic arc; and (b) the uplifted Anatolian plateau bounded to the south by the Cyprus subduction zone. Understanding the Miocene to Recent tectonic development helps elucidate the kinematics of the region. The new structural data presented lend no support for recent suggestions that the Isparta Angle and Antalya Bay represent parts of a regional compressional zone related to plate collision. © 1998 Elsevier Science B.V. All rights reserved. Translation permission of this article has been taken from Elsevier (CCC) on April 01 2015 date and 3600420598320 Licence number