This study is carried out in the vicinity of Cokelezdag (NE of Denizli, Turkey), the Tertiary sedimentary sequences unconformably overly the Mesozoic basement rocks. A number of samples were collected from the measured stratigraphical section, and whole rock and clay mineralogy were determined from these samples. Calcite, mica, feldspar, quartz, clay and dolomite are the main minerals identified. In the clay fraction, smectite is the dominant clay mineral; lesser amounts of illite, chlorite, kaolinite and serpentine were also identified. Provenance studies indicated that the sediments were transported from two different source areas, namely are Taurid ophiolitic belt and Menderes metamorphic massif. Magnesium rich fractions and Aluminium rich fractions were derived from the Taurid ophiolitic belt and the Menderes metamorphic massif respectively.