GEOLOGY OF THE AKDAĞ MASSIF AND SURROUNDINGS

Abstract

The study area is located in the eastern part of Akdağ massive and its surrounding area. The purpose of this paper is to contribute in understanding of the regional geology. In the study area, Akdağmadeni Lithodem represents basement rocks consisting mainly of gneiss, amphibolite, schist, marble and quartzite The metamorphic assemblage underwent metamorphism in the higher temperature part of amphibolite fades and was intruded by granitoids and gabbro. The contact between metamorphics and Paleocene volcanics is tectonic. The units showing different fodimentary environments were deposited during Eocene. For example, in the northern part of the area, Eocene units were represented by hemi-petegic elastics which overlie Paleocene volcanics conformably and olistostromal rocks composed of Upper Cretaceous mega olistolithes. Within some of the olistolithes there is a sharp fades change between Campanian pelagic limestone and Maastrichtian turbidites. Maastrihtian turbidites pass to the Maastrichtian-Paleocene (?) volcanics conformably. Ophiolitic: melange overlies the olistostrome by a north ward-dipping overthrust and, passing to the Campanian hemipelagic limestone in the upper levels, in trio southern part of the area, the Eocene units are represented by shallow marine deposits and overlie the metamorphic rocks unconformably. This sequence is followed by Oligocene and Lower-Middle Miocene continental deposits respectively. The Upper Miocene-Pliocene fluviatile and lacustrine deposits overlie the rest of the older units unconformably. In the neotectonic period, in the study area, the faults showing left lateral-reverse oblique slip in NE-SW trending, right lateral oblique slip in NNW-SSE trending and dip-slip faults in N-S trending, were developed under the control of N-S compression.