The Eocene-Oligocene boundary shows a complex combination of 10 or more types of minerals such as quartz, cristobalite, barite, illite, apatite, clinoptilolite, phillipsite, montmorillonite, goethite and hornblende, and calcite is contained only at the top and bottom. Abundant Fe element and Fe-group elements such Ni, Co and Ir are contained in the layer. Microtektites are also found in the layer, especially in the bottom of it. This shows the formation of the metalliferous claystone may have some relationship with meteorite impact. Based on the mineral composition of the strata between the Eocene and early Oligocene, the distribution of microtektites, the extinction of many organisms, the fluctuations in calcite compensation depth, and so on, the authors infer that a catastrophic event from a meteorite impact may have occurred at the end of the Eocene.