EVIDENCES OF DUCTILE DEFORMATION IN EVAPORITES AROUND ZARA AREA (E SİVAS), SİVAS BASIN

Abstract

A series of ductile deformation evidences and large-scale tectonic lines which remain enigmatic in the light of rigid tectonics principles were observed around Zara and Bolucan areas in the Sivas basin. One group, the evaporite walls which are closely related with the Oligocene-Lower Miocene evaporitic levels, traverses the basin for 30-40 km in an approximate E-W direction. Throughout the contacts, vertical to overturned evaporitic rocks face with the younger sediments as well as with thrusts and folds. Evaporitic diapirs of varying sizes, and basement and cover rock inclusions in the order of several 100's meters to km constitute the smaller scale second set of evidence of this kind of deformation. The available stratigraphic and tectonic data lets us suggest that the ductile deformation occurred subsequent to the NS compression. Also speculated, that the areal extension of the Oligocene-aged Hafik gypsum is of utmost importance and the basaltic volcanism appeared in late Miocene may well be a factor decreasing the viscosity of evaporites and hence accelerating the phenomenon.