The petrology of Paleogene volcanism in the Central Sakarya, Nallıhan Region: Implications for the initiation and evolution of post-collisional, slab break-off-related magmatic activity

The geochemical features of both the Nallıhan and Kızderbent volcanics are best explained as the result of slab break-off, in which the Nallıhan volcanics (located closer to the original subduction front) were produced mainly by the melting of upwelling asthenospheric mantle. Further back from the subduction front, the upwelling interacted with more highly metasomatized sub-arc mantle that underwent partial melting to produce the Kızderbent volcanics. This geodynamic scenario can be used for understanding other post-collisional slab break-off-related magmatic activities.