Paleomagnetic evidence for substantial rotation of the Almacik flake within the North Anatolian Fault

Palaeomagnetic data on Eocene rocks from within the 'Almacik Flake', bounded by two strands of the North Anatolian right-lateral fault indicate that the flake has undergone an apparent counterclockwise rotation of about 148 " on average. We interpret this as a real 212 " clockwise rotation, because the Almacik flake is entirely delimited by the right-lateral North Anatolian Fault strands, the only dominant post-Eocene structure in the area, and because areas surrounding the flake do not show the same rotation. This rotation must have occurred since the North Anatolian Fault originated in the late medial Miocene (late Serravallian: 11.5Ma) and, if so, may imply either a larger total slip along it than hitherto estimated or that the Almacik flake is the surface expression of a flower structure rotating above a shear zone narrower than the present width of the flake