Abstract: Menderes Massive covers an extensive area in soutwestern Anatolia forming a dome-like structure. It consists of a core characterized by augen-gneiss, granite-geneiss and migmatites and an envoloping very low-to low gradeschist sequence. The present study which hes been carried out in the northern part of the massif, near Simav, suggestspelitic sediments and shales for original rocks of the core metamorphised in almandme-amphibolite facies weth migmatization in deepar sections. The core is unconformably overlain by cover-schists at the base contain fragments ofkyanite, staurolite, turmaline and higher grade metamorphic rock. Basic and ultramafic rocks, which are closely relatedto the cover-schists of Paleozoic age reveal a similar kind of metamorphism and folding with these cover-schists. Themetamorpism of the green schists is of Hercynian age. Lower Mesozoic elastics containing schist pebbles, overlie thecover-schists with an angular uncorformity.