THE KAZOVA BASIN - AN ACTIVE NEGATIVE FLOWER STRUCTURE ON THE ALMUS FAULT ZONE, A SPLAY FAULT SYSTEM OF THE NORTH ANATOLIAN FAULT ZONE, TURKEY

The Kazova basin is located within the Almus Fault Zone (AFZ), a splay fault system of the North Anatolian Fault Zone, in the central Pontid es, Turkey. It is a 0.7-10-km-wide, 60-km-long, wedge-shaped right-lat eral strike-slip depression bounded by the Mercimekdagi-Camdere fault set in the north and the Tokat fault set in the south. The Kazova basi n is superimposed on pre-Pliocene basement rocks while its basin fill comprises the Pliocene to lower Quaternary Kizkayasi and Cerci formati ons, and Quaternary alluvials. The Mercimekdagi-Camdere and Tokat faul t sets of the AFZ, the basin-margin faults of the Kazova basin have a considerable amount of normal separation, and show a divergent charact er. Here, the Kazova basin is interpreted as an active negative flower structure, where the combination of normal movement (extension) along the different segments of the AFZ, and the oblique extension between its branching splays resulted from a natural response to the anticlock wise rotation along the AFZ are suggested basin-forming mechanism. Thi s kind of basin is first reported from Turkey although different types of strike-slip basins, such as fault-wedge, pull-aparts, composite pu ll-aparts, are widely represented and well-known.