Role of Late Cretaceous volcanic-sedimentary melanges, specifically the Alada? melange, E Turkey, in the rift-drift-subduction-accretion-emplacement history of the Tethyan Inner Tauride ocean

The Alada? melange is located between Mesozoic Tauride carbonate platform units and the Late Cretaceous Pozant?-Karsant? ophiolite its metamorphic sole. comprises a lower, mainly sedimentary unit, composed of variably disrupted thrust sheets deep-sea sediments, with localized matrix mass-flow turbidity current deposits. upper, volcanic-sedimentary highly basalt-pelagic carbonate-radiolarite units, rarely associated gravity-flow Tholeiitic to alkaline basalts in range from N-MORB, E-MORB OIB, are dated as Middle Jurassic Early using Radiolaria interbedded pelagic sediments. Comparisons accretionary melanges throughout southern Turkey elsewhere indicate similar geochemical pattern variable ‘enrichment’, commonly coupled subduction influence (e.g. negative Nb, Ta anomalies). Geochemically, subduction-influenced consistent an oceanic island arc origin. However, geological setting Triassic within some Mersin) indicative rifted continental margin setting. Turkish considered here erupted along distal, outer northern continent, followed by subduction-accretion supra-subduction zone emplacement. Regional global chemical comparisons suggest that could represent inheritance rather than contemporaneous subduction.