ASTRONOMICAL EVENTS IN THE STRATIGRAPHIC RECORDS AND THEIR IMPLICATIONS

Sedimentary rocks record many astronomical events that occur during geological past. Among them,Milankovitch cycles,tidal rhythmites and astronomiacl impact have been paid much attention. The layers,resulted from these events and usually accompanied with geochemical and biological changes,are worldwidely synchronous and instantaneous,and can act as effective marker beds in chronostratigraphic correlation. A brief introduction for the three astronomical events laid down in rocks and their implications is presented in this paper.