Stratigraphy and Tectonics of the (Dursunbey-Balıkesir) Neogene Graben

Authors: Cevdet BOZKUŞ

Abstract: The Basement of the Kavacık Graben which is confined by extensional or normal faults at the NW an SE margins, is formed by the Upper Cretaceous yayla melange and the Kayacıklar formation of probably Middle-upper Triasic(?) age. The Upper Oligocene-Lower Miocene continental clastics were deposited in the Graben. These clastics deposits include two formations. At the bottom, The Kavacık formation consisting mainly of conglomerates, claystones and marls and conformably overlying upper unit called Umurlar formation is formed by alternation of sandstone, marl, tuff, tuffite and andesitic tuff-laves. Terrace and alluvial deposits, are developed during the Quaternary. The Kavacık Graben initiated as asymmetric-half-graben basin bounded at SE by normal faults and gained the present symmetric structure. The dominant direction of normal faults controlled the graben is N40^0-60^0E. Folds with axis parallel to faults were developed in deposits, according to the vertical motions of the faults which continue their activity after the deposition. these mildly bended folds with asymmetrical limds have axis with NE-SW strike.

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