Accretion tectonics of the Neotethyan Ermioni Complex, Peloponessos, Greece

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Abstract
Late Cretaceous-Early Tertiary terrigenous and calcareous turbidites exposed in the Argolis Peninsula of southern Greece represent an accretionary complex assembled during the closure of a Late Cretaceous Neotethyan ocean. Massive sulphide bodies, thrust slices of cherts and serpentinized ultramafics are found imbricated within a tectonic stack of approximately 8 km thickness. Basalts with overlying Cenomanian-Maastrichtian pelagic limestones and metalliferous sediments are found distributed throughout the complex. The basalts give trace-element chemical signatures consistent with an origin at a mid-ocean ridge or back-arc basin. Folding and shearing is locally intense in fault zones 10-20 m across, resulting in a block-in-matrix fabric. Metamorphism within the complex is of low-to-high diagenetic grade, with grade generally increasing structurally up-section. Palaeo-slope indicators suggest that the ocean basin lay to the present SE. The SSW to NNE emplacement is at variance with the SW-vergent Early Tertiary thrusting of the Hellenides. and may be explicable in terms of transpressional tectonics along the southeastern termination of the Pelagonian micro-continent. The processes which assembled the Ermioni Complex appear to have operated in a similar fashion to those seen along the margins of major ocean basins, although active over much shorter periods of time.