Abstract: In this study the source rock possibilities of the Maestrichtian, Paleocene and Eocene sediments cropping out in the western margin of Çankırı basin have been investigatedThe percentage of the total organic carbon (TOC), kerogen types, the vitrinite reflectance values, and the paragenesis of the clay minerals as well as illite crystallinity values have been determined in the shale samples obtainedfrom four measured stratigraphie sections.The results of the analyses; carried out on the Maestrichtian and Lower Tertiary formations suggest that

-They do not contain significant amount of organic matter,

-The available organic matter is more suitable for the production of gas rather tham oil and they have notalso reached to complete maturity.

Similar analyses were also applied to the upper part of the Haymana formation (Maestrichtian) of the Haymana region- It is again concluded that the shales of the upper part of this formation are rather poor in organicmatter and they do not show good maturity.