Very low grade metamorphism of Triassic volcanics, West Hellenic nappes, southern Peloponnese, Greece: Summary

Abstract

The Stefania Volcanics are a series of (?)mid-Triassic basalt, andesite, rare dacite, and rhyolite hypabyssal intrusions and flows, together with voluminous pryoclastic and volcaniclastic deposits (Pe-Piper and others, 1981). They crop out in central Lakonia in the southern Peloponnese (Fig. 1), forming part of the Tyros Beds, which, together with more highly metamorphosed rocks (including the Krokee Metamorphic Complex) make up the “Semi-metamorphosed” or Phyllite Series (Panagos and others, 1979). The type locality of the Tyros Beds lies 50 km to the northeast at Tyros, and includes volcanic rocks very similar to the Stefania Volcanics. The Phyllite Series forms part of the West Hellenic nappe sequence (Jacobshagen and others, 1978). It may have originally formed the basement to the Mesozoic limestones and Cenozoic flysch of the Gavrovo-Tripolis isopic zone (Richter, 1974) or may have accumulated in a more westerly isopic zone (Jacobshagen and others, 1978). The Stefania Volcanics have suffered very low grade metamorphism. The Stefania Volcanics unconformably overlie limestones with Permo-Carboniferous fossils of the Tyros Beds near Faros (Panagos and others, 1979) and appear to conformably overlie Carnian sediments near Molaoi (Brauer and others, 1980). They are overlain by the Norian and younger Tripolitsa Limestone (Thiebault and Kozur, 1979). The metamorphism of the Tyros Beds, including the Stefania Volcanics, is clearly Alpine (Paraskevopoulos, 1964).