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 Pontides, Turkey. It is a 0.7-10-km-wide, 60-km-long, wedge-shaped right-lateral strike-slip depression bounded by the Mercimekdagi-Camdere fault set in the north and the Tokat fault set in the south. The Kazova basin is superimposed on pre-Pliocene basement rocks while its basin fill comprises the Pliocene to lower Quaternary Kizkayasi and Cerci formations, and Quaternary alluvials. The Mercimekdagi-Camdere and Tokat fault sets of the AFZ, the basin-margin faults of the Kazova basin have a considerable amount of normal separation, and show a divergent character. 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 anticlockwise rotation along the AFZ are suggested basin-forming mechanism. This kind of basin is first reported from Turkey although different types of strike-slip basins, such as fault-wedge, pull-aparts, composite pull-aparts, are widely represented and well-known.