Tectonostratigraphic features of the Southern part of the Sivas tertiary Basin around Savcun and Karacaören areas (Ulaş-Sivas) [Savcun ve Karacaören (Ulaş-Sivas) Yörelerinde Sivashavzasi güney Kanarinin tektonostratigrafik Özellikleri]

Abstract

In this study, detailed geological investigations of rock units located in the southern margin of the Sivas Basin around the Savcun and Karacaören regions were carried out to determine the tectonostratigraphic features of the basin. The Savcun area is the first part of this study where the tectonics and stratigraphic relations are mainly controlled by post-Pliocene thrust tectonics. Three different main thrusts are observed from south to north in the area. These are namely the Karapinar, Yeniapardi and Yukariadaköy thrusts. Most of the faults within the Oligocene evaporitic sediments can actually be regarded as back-thrusts developed in the southern part of the Sivas Thrust. One of the important results arised from this study is that the minimum stress (?3) is vertical and the maximum stress (?1) is horizontal and strikes at NNW-SSE and produced numerous folds, with E-W to NE-SW axes, and several strike-slip faults. The contact between the evaporites and the other units indicates thrust component in places. In the Karacaören region, the association of the upper Cretaceous Divri?i ophiolitic melange and upper Maastrichtian-Thanetian Tecer formation were tectonically transported northwards, in the post-early Oligocene time interval. Geometry of the folds developed in the lower Oligocene Selimiye formation and the E-W trending thrusts affecting the Oligocene evaporitic sediments are the field evidences of this transport.