The structural evolution of a Mesozoic continental margin, Othris Mountains, Greece

The detailed structure of a telescoped Mesozoic continental margin sequence in the Othris (=Sub-Pelagonian) zone of eastern central Greece is described. Prior to thrusting in Upper Jurassic/Lower Cretaceous time, the Triassic and Jurassic facies showed an ordered lateral transition from a carbonate platform in the NE, through a submarine fan to a pelagic basin in the SW. The platform is autochthonous and has a continental basement; the pelagic basin probably lay in part on oceanic crust. Carbonates on platform and fan were abruptly succeeded by siliceous deposits. Soft-sediment slumps in the siliceous sequence show a slope to the SW. Soon after this slumping, the slope reversed: olistostromes formed in front of a NE-sloping thrust pile advancing northeastward. Tectonic mélanges also accompanied thrust emplacement. The activation of the margin may be due to initiation of a NE-dipping subduction zone lying to the SW of the map area. Shortly after emplacement of the thrust stack, it was cross-folded, uplifted, eroded and by mid-Cretaceous time transgressed by shallow water deposits. Cenozoic thrusting in the area is absent, though minor rejuvenation of the NE-trending folds took place. High angle late(?) Cenozoic normal faulting is common.