Akademik Veri Yönetim Sistemi
International Geology Review, cilt.38, sa.9, ss.788-806, 1996 (SCI-Expanded)
The Cankiri Basin evolved as a detrital basin during the Late Tertiary in Central Anatolia between the Pontides (Sakarya continent) and the Kirsehir block. It is E-W trending, and along its southern border it overlies the Kirsehir block unconformably. The Kirsehir block consists of two tectonic belts. Structurally, the lower unit is the Kirsehir Massif, consisting of a platform sequence and a marble association; the upper unit is the Cicekdag belt. The Cicekdag belt consists of thick mafic volcaniclastic rocks and interbedded sediments and rare gabbro masses. This belt probably was developed as a primitive island-arc in the Neotethys ocean. During the Late Cretaceous period, the Cicekdag belt was thrust southward onto the Kirsehir platform. Consequently, the overburden of the nappes caused metamorphism of the Kirsehir platform and the lower parts of the Cicekdag belt. The Yozgat magmatics, consisting of granitic plutons and dacitic rhyolitic lavas, intruded into the Kirsehir block, which was formed by the tectonic stacking of the Kirflorinehir platform and the Cicekdag belt. Geochemically, the Yozgat plutons are of the I type, and probably were formed by subduction of the Inner Tauride ocean underneath the Kirsehir block. During the Late Cretaceous period, another subduction event occurred in the Tethys ocean: along the southern border of the Sakarya continent, a thick ophiolitic melange prism was formed. This melange association is known as the Ankara melange. As a result of these different subduction zones along both the northern and southern margins, the Neotethys ocean was closed and the Kirsehir and Sakarya continents collided. The Cankiri Basin was formed along this collisional zone. The late Paleocene and younger sedimentary fill of the basin is asymmetrical in a N-S direction. The southern part of the Cankiri Basin was a quiet depositional environment, as represented by shallow-sea units and/or continental deltaic rocks. In these environments, interfingering red conglomerates, mudstones, green shales, and shallow-marine fossiliferous limestones were formed. In the central and southern parts of the basin, weakly alkaline trachyandesitic volcanic rocks were formed, which are represented predominantly by andesitic palagonite tuffs, agglomerates, and lavas. Along the northern edge of the basin, on the other hand, deep-sea flysch-facies sediments were deposited. The northern border of the Cankiri Basin was tectonically active throughout its evolution. Because of the progressive convergence of the Kirsehir and Sakarya continents during the late stage of the collision, the ophiolitic melange prism, which originally was formed along the southern edge of the Sakarya continent, was thrust onto the basin. In front of the ophiolite nappes, debris-flow deposits and olistostromes were formed. © 1996 Taylor & Francis Group, LLC.