Regional Survey of Geology & Mineral Resources, Changchun 130012, China

It has been over a half of century since Chuandishan basalt christened in 1953. Because of no isotopic geochronology data for this volcanic event in the strototype of the basalts and many Cenozoic high position basalts, similar to the Chuandishan basalt in Northeast China, the name of Chuandishan basalt has been widely used in a lot of related papers on the basalts formed by different volcanic events in Paleocene-Pliocene in this region, which led to enlarge the time span of this name and bring inconvenience to the study of Cenozoic volcanic event sequence in Northeast China. The dating of the Chuandishan basalt on top of the stratotype section indicates that the whole rock age of K-Ar is ( 28.3 ±2.3) Ma1 Combined with other documents, the Chuandishan basalt can be recognised as an event stratigraphic unit, or it can be considered in board sense as a volcanic stratigraphic unit formed by volcanic events in late Oligocene sedimentation.