Abstract: The Cretaeeous-Tertiary boundary is gradually transitional in the carbonate rocks of Tecef Formation.This transition has no fossil and it can be distinguished by lithologie, minéralogie and geohemical data. Typical fossilsrepresenting the Uppermost Maastrichtian and Danian have been seen in the lower and upper parts of K-T transtition,The carbonate mineral of Upper Maastrictian formed of limestone is calcite, and the main minerals of its clay fractionare illite and chlorite. Dolomite appears in both K, T and Danian-Montian-Thanetian transitions. Smectite and 14S-14Cin the Paleocene are the dominant clay minerals. The mean amounts of Mg, Fe, Cr, Ni and Zn in the carbonate mineralsrelating to Paleocene increase, when compared with those of Upper Cretaceous, In addition, it has been detected that Fe,Cr, Co and Zn contents of non-carbonate residual fraction are more abundant in the Paleocene.