Jeoloji Münendisliği Dergisi

Structural Setting of Alanya Masif

ABSTRACT: The aim of this paper Is to discuss structural and petrologlc questions that have evolved in relation to Âlanya massif of Western Taurids. The paper will mainly deal with structural setting of the massif with minor reference to degree and baric type of metamorphlsm, nature of original rook sequence and a rough age for the final effective deformation. Intermediate to high confining pressure as well as fairly high vapour pressure is Indicated by glaucophane - plstaclte assemblage for Gündoğmuş region. Similar vapour pressures must have prevailed İn Alanya region for the formation of amphibolites Intercalated with the metasedimentary sequence. However, no geobarometers have been detected In this area. The temperatures must have ranged from the boundary of anchimetamorphism to about 500°C corresponding to the high temperature part of low grade metamorphism (Wlnkler, 1974) below the isograd «Hornblend- Am? In», The original rocks are pelites and carbonates with minor eXtruslves. The age of final effective deformation is pre - Upper Triassic indicated by metamorphic rock fragments in Upper Triassic sandstoones and conglomerates. The structural setting is controversial, Helvetic type nappe model being defended by the French school (Brunn et al., 1973) and Özgül (1976). Earlier structural models presented by Blumenthal (1951) is supported by new evidence. Strong field evidence is presented to reject any thought of post-Jurassic allochtony or large displacements of tectonic units relative to one another. Jurassic carbonates connected to the autochtonous sequence (Geyikdağı Birliği; Özgül, 1976) mutually cover Âkıncibell formation of Lower Triassic age and metamorphlcs of Alanya massif. However, movement of the whole section relative to an oceanic lithosphère may be considered a plausible thought. Thus, excluding plate motions from the concept of allochtony, Alanya massif constitutes stratigraphie and structural basement of Western Taurids. The Whole section is formed by a normal sequence transformed in to northly dipping tectonic slices by Tertiary movements.