Abstract: This study describes the fades and environmental aspects of the Güvenç formation (Burdigalian-Serravalian) of the TertiaryAdana Basin. For this purpose. Karaisalı-Güvenç-Kuzgun and Çukurköy stratigraphic sections are measured, and geometry, sedimentary structures with paleocurrent patterns and micropaleontological (bentonic, planktonic foraminifera and nannoplankton) deter mi nat ions!countings are evaluated.The Güvenç formation comences with talus deposits and fore-reef shales on the trangressive cycle deposits of the Adana Basinof the Karaisalı formation and grades up in the  basinal shales. In accordance with the general shallowing of the basin, these basinalshales are overlain by the shallow marine and terrestrial Kuzgun formation (regressive cycle) at the upper parts of the succestion.The unit shows relativly deep marine conditions with decreasing amount of the sandy layers and benthonic foraminifera, andincreasing amount of the planktonic foraminifera and Discoaster type of nannofassiU from bottom to the middle part of the succession. Dominant pyrilization between 562-2000 meters of the succession indicates aneorobic environmental conditions for this interval. On the other hand, increasing amount of detrial material, benthonic foraminifera and Braarudosphaera discula, Braarudosphaera bigelowi type nannoffossils also display that relatively shallow marine conditions for the uppermost parts of the succession.