An olistostrome-melange belt formed along a suture: Bornova Flysch zone, western Turkey

Okay, Aral
İşintek, İsmail
Altıner, Demir
Altıner, Sevinç
Okay, Nilgün
The Bornova Flysch Zone (BFZ) in western Turkey is a regional olistostrome-melange belt located between the Izmir-Ankara Tethyan suture in northwest and the Menderes Massif in the southeast. The BFZ consists mostly of tectonized gravity mass flows. The blocks are Mesozoic limestone and ophiolite, which are enclosed in Cretaceous-Paleocene sheared sandstone and shale. The limestone blocks are of two types. The first type consists of Late Triassic to Cretaceous shallow marine carbonates. The second type has an Upper Triassic shallow marine section overlain by Jurassic to Cretaceous pelagic limestones. A semi-intact part of the platform occurs in the Karaburun peninsula and on the island of Chios. The ophiolitic blocks in the BFZ include ultramafic rock, gabbro, basalt and radiolarian chert of Middle Triassic to Cretaceous in age. The formation of the BFZ overlaps with the Cretaceous subduction and HP/LT metamorphism of the northern passive continental margin of the Anatolide-Tauride Block. This subduction zone was bounded in the west by a strike-slip tear fault. The BFZ formed in a narrow basin between this tear fault and the Tethyan ocean. The mass flows came from the southeast from the overriding ophiolite and accretionary complex, and from the northwest from the uplifted segments of the platform margin. This model provides an explanation as why the BFZ is unmetamorphosed, whereas the equivalent strata in the Menderes Massif were metamorphosed at depths of over 20 km. It also explains the prominence of gravity flows and the southward younging in the BFZ, and for the apparently anomalous observation that, although the Tethyan ocean lay to the northwest, the ophiolitic blocks are more common on the southeastern part of the BFZ. Regions away from the tear fault, such as the Karaburun peninsula, were least affected by subsidence and deformation during the Cretaceous and Paleocene.


Evidence from the Gediz graben for episodic two-stage extension in western Turkey
Kocyigit, A; Yusufoglu, H; Bozkurt, Erdin (1999-05-01)
Western Turkey falls within a wide belt of NNE-SSW-directed, active continental extension, generally similar to the Basin and Range Province of the USA It comprises a zone of WNW-ESE-trending major grabens. Derailed study of the Gediz graben reveals two contrasting infills that represent two distinct extensional stages, separated by a short phase of compression. The older infill consists of an 800m thick, folded and exhumed continental sedimentary sequence with intercalated calc-alkaline volcanics. It accum...
Radiolarian assemblages of Middle and Late Jurassic to early Late Cretaceous (Cenomanian) ages from an olistolith record pelagic deposition within the Bornova Flysch Zone in western Turkey
TEKİN, UĞUR KAĞAN; Göncüoğlu, Mehmet Cemal; UZUNÇİMEN KEÇELİ, SEDA (2012-01-01)
The Bornova Flysch Zone (BFZ) in NW Anatolia comprises several olistoliths or tectonic slivers, representing various parts of the Izmir-Ankara ocean. Radiolarian assemblages extracted from one of the olistoliths of the BFZ, cropping out along the Sogutulu section, to the NE Manisa city, were studied in detail. The lowermost part of the section contains latest Bajocian - early Callovian radiolarian taxa, followed by radiolarian assemblages indicating Late Jurassic to early Late Cretaceous (Cenomanian) ages. ...
Episodic, two-stage Neogene extension and short-term intervening compression in Western Turkey: field evidence from the Kiraz Basin and Bozdag Horst
Bozkurt, Erdin (2005-05-01)
Western Anatolia (Turkey) is a region of widespread active N-S continental extension that forms the eastern part of the Aegean extensional province. The extension in the region is expressed by two distinct/different structural styles, separated by a short-term gap: (1) rapid exhumation of metamorphic core complexes along presently low-angle ductile-brittle normal faults commenced by the latest Oligocene-Early Miocene period, and; (2) late stretching of crust and, consequent graben evolution along Plio-Quate...
Göncüoğlu, Mehmet Cemal; Sayıt, Kaan; Ottria, Giuseppe; Pandolfi, Luca; Ellero, Alessandro (2012-12-01)
The Ayli Dag ophiolites occur as an independent tectonic unit within the Intra-Pontide suture zone, central-northern Turkey. They crop out, together with the other units of the Intra-Pontide suture zone, at the top of the Late Cretaceous-Middle Paleocene foredeep sediments of the Sakarya Terrane. The Ayli Dag ophiolites sequence include in its lower part a mantle sequence consisting of not less than 2-3 km-thick peridotites, topped by 500-600 m-thick layered gabbros with alternating, dm- to m-thick layers o...
The Tarakli Flysch in the Boyali area (Sakarya Terrane, northern Turkey): Implications for the tectonic history of the IntraPontide suture zone
Catanzariti, Rita; Ellero, Alessandro; Göncüoğlu, Mehmet Cemal; Marroni, Michele; Ottria, Giuseppe; Pandolfi, Luca (2013-11-01)
In the Boyali area, northern Turkey, the tectonic units of the Istanbul-Zonguldak Terrane and the IntraPontide suture zone are thrust over the deposits at the top of the Sakarya Terrane, known as Tarakli Flysch. It consists of Early Maastrichtian-Middle Paleocene turbidite and mass-gravity deposits, whose source mainly corresponds to the Istanbul-Zonguldak Terrane, and, with a lesser extent, to the IntraPontide suture zone. These deposits were sedimented in a foredeep basin developed during the convergence ...
Citation Formats
A. Okay, İ. İşintek, D. Altıner, S. Altıner, and N. Okay, “An olistostrome-melange belt formed along a suture: Bornova Flysch zone, western Turkey,” TECTONOPHYSICS, pp. 282–295, 2012, Accessed: 00, 2020. [Online]. Available: