Origin of NE-trending basins in western Turkey

The origin of NE-trending basins and their relation to the E-W-trending grabens in western Turkey have been the subject of long lasting debate. The stratigraphical and structural aspects of the basin fill in the E-W Gediz Graben and in the NE-trending Gordes, Demirci, Selendi and Usak-Gure basins located immediately to the north of the graben are reassessed here. The Gediz Graben is characterized by two contrasting sedimentary packages that are separated by an angular unconformity. These are: (1) a folded Miocene-Lower Pliocene megasequence, exhumed on the shoulders of the graben; and (2) nearly horizontal Plio-Quaternary sediments. In contrast, the NE-trending basins comprise solely Lower-Middle Miocene sediments and unconformably overlying Quaternary alluvium. The Miocene configuration of different trending basins shows close similarities, and suggests that they started to develop simultaneously during the Early,Miocene. Miocene sedimentation in these basins occurred in the hanging-wall of a presently low-angle, north-dipping, major normal fault (detachment fault) that bounds the Gediz Graben to the south, while the metamorphic rocks of the Menderes Massif in the footwall were progressively deformed, uplifted and exhumed. The Miocene sediments in the NE-trending basins were also deformed along broad folds with axes parallel to the basin margins. The extension was therefore partially complemented by a horizontal shortening at high-angle to it, and the basin-bounding faults together with the blocks-they bound have rotated around vertical axes. In this scenario, the NE-basins started to develop as "Aegean type cross-grabens", and the bounding structures are interpreted as "rotational accommodation faults" that accommodate differential stretching in the hanging-wall of the major breakaway fault, accompanying the Early Miocene phase of extension in western Turkey. Later, during the neotectonic extensional period commencing in the Pliocene (5 Ma), the margin-bounding high-angle normal faults of the modern E-W Gediz Graben cut and displaced the presently low-angle breakaway fault. Some parts of the NE-trending basins were therefore trapped within the E-W graben and some other parts remained as hanging basins on the footwall of the normal fault, along the northern margin of the Gediz Graben. It is concluded that the classification of basins for the area of the Gediz Graben and those located to its north as "replacement and revolutionary" structures is still valid. It is also confirmed that the latest Oligocene-Early Miocene back-arc extension and/or orogenic collapse cannot be responsible for the entire history of continental extensional tectonics and the extension in western Turkey is not a continuous event, but occurred in two stages separated by a short period (7-5 Ma); the second being the Plio-Quaternary phase of N-S extension related to the westward escape of the Anatolian block. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.


Age and Chemistry of Miocene Volcanic. Rocks from the Kiraz Basin of the Kucuk Menderes Graben: Its Significance for the Extensional Tectonics of Southwestern Anatolia, Turkey'
Bozkurt, Erdin; Ruffet, Gilles; Rojay, Bora (Informa UK Limited, 2008-09-01)
Neogene volcanic rocks and granitoid plutons are among the most important geological components of western Turkey. Although they are voluminous north of the Gediz Graben, they are very scarce to the south, where volcanic rocks occur as isolated small exposures in a small number of localities. The Kiraz Basin of the Kucuk Menderes Graben is a key locality, in which Tertiary volcanic rocks crop out at three locations. These rocks have been chemically analysed and dated ((39)Ar-(40)Ar whole rock and biotite an...
Age and kinematics of the Burdur Basin: Inferences for the existence of the Fethiye Burdur Fault Zone in SW Anatolia (Turkey)
ÖZKAPTAN, MURAT; Kaymakcı, Nuretdin; Langereis, Cor G.; Gulyuz, Erhan; Özacar, Atilla Arda; UZEL, BORA; SÖZBİLİR, HASAN (Elsevier BV, 2018-10-02)
The Burdur Basin is a late Miocene to Pliocene fluvio-lacustrine basin in SW Anatolia. It is developed within the postulated Fethiye-Burdur Fault Zone, which was argued to be a sinistral strike-slip fault zone developed in response to propagation of the Pliny-Strabo STEP fault into SW Anatolia (Turkey). In order to assess the presence and tectonic characteristics of the fault zone, we conducted a paleomagnetic study in the Burdur basin that involved rock magnetic experiments, Anisotropy of Magnetic Suscepti...
High-altitude Plio-Quaternary fluvial deposits and their implication on the tilt of a horst, western Anatolia, Turkey
Süzen, Mehmet Lütfi; Rojay, B (Elsevier BV, 2006-03-01)
This study investigates the origin and regional tectonic implications of high-altitude Plio (?)-Quaternary fluvial deposits developed over the Bozdak horst which is an important structural element within the horst-graben system of western Anatolia, Turkey. A total of 23 deposits occur near the modem drainage divide comprising fluvial to occasionally lacustrine deposits. The deposits are all elongated in N-S direction with a width/length ratio of 1/10. The largest of them is of 13 km in length with a maximum...
Slab fragmentation beneath the Aegean/Anatolia transition zone: Insights from the tectonic and metamorphic evolution of the Eastern Aegean region
Roche, V; Jolivet, L.; Papanikolaou, D.; Bozkurt, Erdin; Menant, A.; Rimmele, G. (Elsevier BV, 2019-03-05)
Slab tearing below western Turkey had first-order tectonic and magmatic consequences by inducing a lateral gradient of extension in the upper plate and toroidal flow of asthenosphere that affected the typology and distribution of melts at the surface. But the coupling mechanisms between the 3D mantle flow at depth and deformation in the upper plate above a slab tear have received little attention so far. This paper is focused on the description of the distribution and kinematics of deformation in the easter...
Folding of the Gediz Graben Fill, SW Turkey: Extensional and/or contractional origin?
Ciftci, N. Bozkurt; Bozkurt, Erdin (Informa UK Limited, 2008-05-01)
Folds constitute a significant pan within the dominantly extension-related deformation pattern of the Gediz Graben and their origin either extensional or contractional has been the subject of debate. Field and subsurface data presented in this paper suggest that folds of contractional and extensional origin coexist in the graben-fill sediments. Contractional folds are predominantly observed within the Alasehir formation. A north vergent, plunging, asymmetrical to overturned geometry characterizes these fold...
Citation Formats
E. Bozkurt, “Origin of NE-trending basins in western Turkey,” GEODINAMICA ACTA, pp. 61–81, 2003, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36417.