ABSTRACT: The objective of this study is the clastic sequence of Early Tertiary age, widely exposed to the south of Gemlik (Bursa). The sequence has been divided in to five distinct rock units, in ascending order: Segköy mudstone-eonglomerate unit, the Diirdane mudstone-sandstone unit, the Kurtul calcerouus mudstone unit, Hisartepe limestone unit and the Gençali mudstone-sandstone unit. The Seçköy unit is made lagely of volcanoclastic conglomerates. T^e Dürdan© unit consists of reddish, brownish mudstone, lithic sandstone and subordinate conglomérâtes. The Kurtul unit is made up of yellowish to whitish caicerous mudstone* The Hisartepe limestone is composed of white bioclastic limestone which includes abundant Early Eocene (Ypresien) fauna! elements. The Gengali unit consists of a thick interbedded succession of intercalating yellowish, greenish and reddish mudstones and thickly-bedded greenish sandstones The units are conformably stratified. The approximated total thickness of the studied elastic sequence is more than 630 m. The Sedimentologic and paléontologie characteristics of the units indicate a near-shore depositional environment.