Tectonic implications of transtensional supradetachment basin development in an extension-parallel transfer zone: the Kocaçay Basin, western Anatolia, Turkey
Article first published online: 9 DEC 2010
© 2010 The Authors. Basin Research © 2010 Blackwell Publishing Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologists
Volume 23, Issue 4, pages 423–448, August 2011
How to Cite
Sözbilir, H., Sarι, B., Uzel, B., Sümer, Ö. and Akkiraz, S. (2011), Tectonic implications of transtensional supradetachment basin development in an extension-parallel transfer zone: the Kocaçay Basin, western Anatolia, Turkey. Basin Research, 23: 423–448. doi: 10.1111/j.1365-2117.2010.00496.x
- Issue published online: 4 JUL 2011
- Article first published online: 9 DEC 2010
- Manuscript received 24 June 2009; Manuscript accepted 22 October 2010.
The Kocaçay Basin (KÇB) is a key area in western Anatolia – a well-known extended terrane where regional segmentation has received limited attention – for investigating strike-slip faults kinematically linked to detachment faults. In this paper, we present results of an integrated sedimentologic, stratigraphic, and structural study of Miocene alluvial fan/fan-delta/lacustrine deposits that accumulated in the KÇB, a NE-trending basin with connections to the Menderes Metamorphic Core Complex (MCC). We mapped and evaluated most of the key faults in the KÇB, many for the first time, and recognised different deformation events in the study area near the E margin of the MCC. We also present field evidence for kinematic connections between low-angle normal and strike-slip faults which were developed in an intermittently active basement-involved transfer zone in western Anatolia. We find that the KÇB contains a detailed record of Miocene transtensional sedimentation and volcanism that accompanied exhumation of the MCC. Structural data reveal that the basin was initially formed by transtension (D1 phase) and subsequently uplifted and deformed, probably as a result of early Pliocene wrench- to extension-dominated deformation (D2 phase) overprinted by Plio-Quaternary extensional tectonics (D3 phase). These results are consistent with progressive deformation wherein the axis of maximum extension remained in the horizontal plane but the intermediate and maximum shortening axes switched position in the vertical plane. Combining our results with published studies, we propose a new working hypothesis that the KÇB was a transtensional supradetachment basin during the Miocene. The hypothesis could provide new insights into intermittently active extension-parallel zone of weakness in western Anatolia.These results also suggest that the termination of low-angle normal fault systems within an extension parallel transfer zone may have resulted in a transtensional depressions which are different from classical supradetachment basins with respect to the sedimentation and deformational pattern of the basin infills.