In Oman, the sedimentary basins located along the edges of the Oman Mountain chain show continuous sedimentation at the K/T boundary. Two distinct sedimentary palaeoenvironments have been analysed. In the northwestern flank of the Oman Mountains (near Buraymi), the K/T boundary occurs within hemipelagic deposits, whereas in the Abat basin (southeastern flank), it occurs within confined carbonate platform facies. The negative delta 13 C shift and the positive iridium anomaly, which characterize the global geochemical events of the K/T boundary in marine sections, have been detected in Oman. Moreover this isotopic signature is not the only event recorded in these sections. Some other important shifts have been recognized in the Upper Maastrichtian and Lower Danian sediments. These shifts are related to some palaeogeographical events such as platform flexuration which correspond to some regional tectonic reajustments.