Evidence from the Gediz graben for episodic two-stage extension in western Turkey

Kocyigit, A
Yusufoglu, H
Bozkurt, Erdin
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 accumulated in a basin formed in the northern hanging wail of a detachment fault during Miocene-early Pliocene times. The younger infill rests on the older infill with angular unconformity and consists of about 170 m of undeformed, terraced continental sediments and basaltic lavas. It accumulated during Plio-Quaternary times in an asymmetric graben bounded by step-like normal faults. This later extension was probably triggered by the commencement of sea-Boor spreading along the Red Sea in early Pliocene times and has persisted to the present. Almost all the grabens in western Turkey are best explained by this episodic, two-stage graben model with an intervening phase of short-term compression, which differs from the progressive evolution inferred for the Basin and Range Province of the USA.

Citation Formats
A. Kocyigit, H. Yusufoglu, and E. Bozkurt, “Evidence from the Gediz graben for episodic two-stage extension in western Turkey,” JOURNAL OF THE GEOLOGICAL SOCIETY, vol. 156, pp. 605–616, 1999, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36037.