Keywords: 
• biological extinction /
• dinosaur fossils /
• capped way sedimentation /
• event sedimentation

Abstract: The phenomen n that dinosaur fossils can be preserved very well shows that dinosaurs were rapidly buried and preserved after or before their death. The strange phenomenon that a number of dinosaur fossils were unearthed in complete body frames or throngs in the Upper Cretaceceous clastics nearly around the globe indicates that this set of clastics which buried dinosaurs should belong to a kind of "event sedimentation". On the other hand, the formation of the late Upper Cretaceous have such features as: ① Together with the Eogene above, a complete Ⅱ-class sedimentary cycle was formed. Among them there was a conformable contact, and the classfication limit was determined by the distinguishing line of dinosaurs or by the appearance line of mammalia. The micropalaeobio logics show the mixing feature of Meso zoic-Cenozoic molecules. ② This set of strata overlapped on the earier layers in widespread way or in capped way; and it is of large thickness, similar features and easy correlation.③ There is an unconfomity at the bottom of the strata which can be correlated worldwide. ④ The geologic time of forming the strata is very short. ⑤ There are abnormal transgressive feature. The comprehensive analysis shows that this kind of sedimentary strata can be formed only under widespread way or capped way catastrophic flood conditions. This set of sediments are called "event sedimentation" relation to the normal sedimentation. The catastrophic flood of forming the event sedimentation may be the catastrophic seaquake worldwide, and it is caused by the planet collision. In order to explain the abnormal phenomenon that the biological distinguishing line is underlying the argillic horizon, the clastics concluding dinosaur fossils and iyidium-rich argillic horizon are considered as the different part of "event sedimentation" in this paper. A lot of transporting matter carried by the catastrophic seaquake worldwide deposited repidly in very short time, and some organism such as dinosaurs were preserved completely, then come the sedmentation of the iydumrch matter in the air. This special kind of transgression may by one of the causes of the marine organism and salt-deposit that have been argued in the inland basins.