Tectonostratigraphy of the southern sivas tertiary basin (central turkey) and comparison with landsat mss imagery
The Sivas Basin is one of the most important sedimentary basins, in terms of tectonics and hydrocarbon potential, in the Central Anatolian region of Turkey. Its development is related mainly to the closure of the northern branch of the Neotethyan ocean, as well as to influences of the closure of the Inner Tauride ocean. This basin's complex history is related to several successive orogenic phases during the Cenozoic. Other interesting characteristics of this basin, as in the Central and Eastern Anatolian basins, are the tectonics and lithological features associated with the younger gypsum deposits. The study area comprises two distinct regions, namely the Savcun and Karacaoren areas. The primary stratigraphie relationships between Lutetian turbidites, Oligocene continental gypsum and detritics, and lower to middle Miocene continental deposits of the Savcun area have been elucidated. In this part of the study area, S-verging imbricated thrust systems, mainly located within the gypsum series, developed during roughly N-S compression. The base of the tectonostratigraphic pile of the Karacaoren area includes an Upper Cretaceous ophiolitic melange and overthrusts on the younger deposits. This melange is unconformably overlain by Maastrichtian-Thanetian limestones and detrital rocks. Lutetian detrital turbiditic rocks transgressively overlie older units. An Oligocene sequence (gypsum and detritics) was deposited in E-W-trending intermontane basins developed during N-S contraction, following the Eocene-Oligocene transition. Lower to middle Miocene continental and shallow-marine deposits unconformably overlie all the aforementioned tectonostratigraphic units. Additionally, ENE-WSW-trending fold axes, thrust faults, and several lineaments developed along the general trend of the regional compressional regime in late Miocene time. The stratigraphie and tectonic features of the investigated areas are revealed through a comparison of the results obtained by geological mapping and interpretation and analysis of Landsat MSS images. © 1997 Taylor & Francis Group, LLC.