UPPER CRETACEOUS/PALEOCENE TRANSITION RELATIONS IN THE GÜRÜN AUTOCHTHON, EAST TAURIDES-SW SİVAS (TURKEY)

Abstract

The aim of this study is to determine the upper Cretaceous/Paleocene relation in the Akdere Basin (Gürün-SW Sivas) of eastern Taurids. The upper Cretaceous/Paleocene boundary in the studied is well observed. Microbreccia levels with intraformational conglomerate/breccia and biogenic limestone occurrences exist in places along the upper Cretaceous/Paleocene boundary. The rocks in the microbrecciated character show a texture of biolithclast packstone-grainstone and their depositional environment grades from slope to the basin. Most of the intraformational conglomerate/breccias on the upper Cretaceous/Paleocene boundary indicate possible movements of the sea floor controlled by tectonism during this time. On the uplifted blocks of the faults, syngenetic with the sedimentation, an environment which is vulnerable for some reefbuilding organisms, such as algae-corals and Bryozoa, was developed and biogenic limestones were deposited. Intraformational conglomerate/breccias were accumulated as resedimented rocks on the slopes and steeps of the fault fronts. As a result of these activities, sedimentary fissures (Neptunian dykes) were formed due to the crackings on the sea floor. This basin movement on the upper Cretaceous/Paleocene boundary gave also rise to the development of local uncorformities (hiatus).