Direction of ophiolite emplacement inferred from Cretaceous and Tertiary sediments of an adjacent autochthon, the Bey Dağlari, southwest Turkey

Abstract

The late Mesozoic to mid-Tertiary depositional history of an autochthonous block in southwest Turkey is outlined in relation to the direction of emplacement of adjacent allochthonous units. In this area, a lively debate persists as to whether the Antalya Complex, located along the Mediterranean coast, should be correlated with the Lycian Nappes, sited to the northwest in central western Anatolia. Both allochthonous bodies include Mesozoic ophiolites and similar shallow- to deep-water sedimentary facies. Correlation of the Antalya Complex and the Lycian Nappes requires transport over the adjacent autochthon, the Bey Daglari. Here field data from the southern part of the Bey Daglari are used to trace the depositional history of the autochthon from Late Cretaceous to late Miocene time. A pattern of late Mesozoic pelagic carbonate deposition giving way to more heterogeneous sedimentation in the early Tertiary is documented. By early Miocene, the autochthon was blanketed by a thick sequence of Miocene elastics, mostly derived from an ophiolite. Evidence from sedimentary structures shows that transport was from the east and northeast. Depositional models are advanced which involve an early Miocene delta-submarine fan giving way in later Miocene times to an alluvial fan. Demonstration that in this area the ophiolite material was derived from the east provides additional important evidence of the existence of a southerly Mesozoic oceanic basin, distinct in origin from the Lycian nappes to the north.