Gödene Zone, Antalya Complex: Volcanism and sedimentation along a Mesozoic continental margin, S. W. Turkey

Abstract

The Godene Zone, Antalya Complex, is an assemblage of ophiolitic and associated sedimentary rocks formed on a passive margin during and after the rifting of a Mesozoic ocean basin. The zone comprises late Triassic alkaline mafic submarine lavas and sediments, mostly pelagic, which are tectonically intercalated with mafic/ultramafic plutonic rocks, taken to be remnants of an original ophiolitic substratum. The Godene Zone also includes major limestone massifs and tectonised remnants of former carbonate margin facies. Early Triassic rifting initiated a horst-graben terrain, with localised evaporite and clastic deposition. By late Triassic time continued extension allowed substantial extrusion of submarine mafic volcanics. These were often erupted close to tectonically active fault-scarps, generating both epiclastic and pyroclastic volcanic breccias. Several large slivers of continental basement were rifted off to form major offshore massifs which remained as topographic highs throughout the Mesozoic. During late Triassic time, exposed parts of the continent (Bey Daglari) and the offshore massifs shed siliciclastics, mostly turbidites, above the mafic lavas. Offshore reefs also shed material ranging from substantial detached blocks to finer grainedHalobia-limestone facies. During Jurassic to late Cretaceous time the whole area underwent passive margin deposition. Radiolarian pelagic sediments were deposited in deep water above the ophiolitic basement and around the offshore massifs. The reef complexes persisted until mid-Cretaceous time, when calcareous pelagic deposition was initiated. Passive margin conditions were terminated with deposition of ophiolitic clastics and olistostrome melange in the Maastrichtian, followed by major tectonism.