Stratigraphy of Upper Cretaceous-Palaeogene sequences in the southern and eastern Menderes Massif (western Turkey)

The stratigraphy of the uppermost levels of the Menderes Massif is controve rsial and within its details lie vital constraints to the tectonic evolutio n of south-western Turkey. Our primary study was carried out in four refere nce areas along the southern and eastern Menderes Massif. These areas lie i n the upper part of the Menderes metamorphic cover and have a clear stratig raphic relationship and contain datable fossils. The first one, in the Akbu k-Milas area, is located south-east of Bafa Lake where the Milas, then Kizi lagac; and Kazikli formations are well exposed. There, the Milas formation grades upwards into the Kizilagac formation. The contact between the Kizila gac and the overlying Kazikli formation is not clearly seen but is interpre ted as an unconformity. The Milas and Kizilagac formations are also found n orth of Mugla. in the region of Yatagan and Kavaklidere. In these areas, th e Milas formation consists of schists and conformably overlying platform-ty pe, enemy and rudist-bearing marbles. Rudists from the main palaeontologica l data from which a Santonian-Campanian age is indicated. The Kizilagac for mation is characterized by reddish-greyish pelagic marbles with marly-pelit ic interlayers and coarsening up debris flow deposits. Pelagic marbles with in the formation contain planktonic foraminifera and nanoplankton of late C ampanian to late Maastrichtian age. The Kazikli formation is of flysch type and includes carbonate blocks. Planktonic foraminifera of Middle Palaeocen e age are present in carbonate lenses within the formation. In the Serinhis ar-Tavas area, Mesozoic platform-type marbles (Yilanli formation) belonging to the cover series of the Menderes Massif exhibit an imbricated internal structure. Two rudist levels can be distinguished in the uppermost part of the formation: the first indicates a middle-late Cenomanian age and the upp er one is Santonian to Campanian in age. These marbles are unconformably co vered by the Palaeocene-Early Eocene Zeybekolentepe formation with polygene tic breccias. In the Cal-Denizli area, the Menderes massif succession consi sts of cherty marbles and elastic rocks with metavolcanic lenses. The Lower -Middle Eocene Salvan formation lies unconformably on this sequence and is interpreted as equivalent to the marble horizons at Serinhisar but with pel agic facies. The Salvan formation consists of shale, mafic volcanic rock, l enses of limestone and blocks of recrystallized limestone. The Salvan forma tion is dated here for the first time by Early-Middle Eocene foraminifera a nd nanoplankton from the matrix of the formation. An angular unconformity e xists between the Upper Cretaceous and Lower Tertiary sequences, suggesting that a phase of deformation affected the southern and eastern part of the Menderes Massif at this time. This deformation may be caused by initial obd uction of the Lycian ophiolite onto the passive margin to the north of the Menderes carbonate platform during the latest Cretaceous, Drowning of the p latform led to termination of carbonate deposition and deposition of deep w ater flysch-like elastic sediments.