Abstract: This study is intended to provide some critical sedimentological and petrological data frompreviously poorly known seqences on the northern flank of the Haymana anticline. Information has beenprovided on the paleocurrents, thin section petrography, heavy minerals and clay minerals of the Upper Cretaceous-Eocene rocks in this region. The sue cessions of the eastern and western parts of the Haymana area consist of deep marine sediments, such as resedimented conglomerates associated with bioolastic and epiclastic sandy turbidites. The general sequ- ence starts with a sandy turbidite formation (HaymanaFormation-Maestrichtian) including conglomerates (wh ich are more abundant in the western area) and continues upwards with the olistolith bearing bioclastic limestone Yeşilyurt Formation. (Montian-Thanetian)which is followed by coarse grained sandstones with conglomerates of the Ilgmlıkdere Formation (Ilerdian). This is overlain by thiribedded sandstones and marls of the Eskipolatlı Formation (Ilerdian-Cuisian)succeeded by the Yamak Formation. In the western area the Yamak Formation consists of amalgamatedsandstones, marls and conglomerates, while in the east the same time interval is represented by theÇayraz Formation (Cuisian-Lutetian) consisting of alternating nummulitic limestones and shales. Paleocurrent directions derived from abundant primary sedimentary structures indicate consistent sedimenttransport from NNW. The composition of the silici lastic sediments demostrates that this northern source of the terrigeneous detritus in the lower formations consisted mainly of magmatic rocks, with metamorphic associates. However, in the upper formations (Eskipolath and Yamak/Çayraz) metamorphicsources became dominant, although magmatic detri tuc was still being supplied. The ill sorted greywacketype sandstones plot in the area of the «subduction complex» on the compositional triangular diagramsof Dickinson (1982), but the overall fields tend to overlap with the fore-arc basin area.