The Kozak Pluton and its emplacement

Abstract

The Kozak pluton is located in central western Anatolia, where it crops out in the core of an antiformal culmination. The pluton was emplaced into regionally deformed and metamorphosed basement rocks, during the Late Oligocene–Early Miocene period. The pluton consists mainly of a homogeneous granodiorite with fine-grained margins. A suite of hypabyssal intrusives of the same composition formed a fringe around the pluton, during the late phases of emplacement. The hypabyssal rocks are intimately mixed with cogenetic volcanic rocks of Early Miocene age. Field evidence suggests that the pluton is a very high level intrusion, although it has features typical of more deep-seated granites. The pluton exhibits different effects on the host rocks along different contacts, which suggests that during its long history of ascent a variety of emplacement mechanisms operated at different depths. These emplacement mechanisms range from diapiric intrusion at deeper levels through cauldron subsidence to passive emplacement. During the latter phase, faults and fractures allowed the pluton to be finally emplaced at sub-volcanic levels. Copyright © 1999 John Wiley & Sons, Ltd.