Cratering events in the Japan Sea and tectonic evolution of East Asia during the Cenozoic

A series of major geological events occurred in Northern Pacific and East Asia during the Eocene about 45 Ma BP.The rifting of the Japan Sea and intracratonic faulting in the eastern part of the Eurasian continent gave rise to the clockwise rotation(>20°) of the eastern part of the Tancheng-Lujiang block including the southwestern part of Japan and northern part of adjacent China blocks during the Eogene.At the ages of about 43 Ma,the NNW-trending Pacific plate recorded by Hawaii hot spots suddenly turned to the NWW direction.The four phases of intense tectonic movements once occurred in the Tancheng-Lujiang fault zone at the ages of 45 to 58 Ma during which the cooling events were caused by the rift faulting of the fault zone.The rift systems were initiated due to the mantle thermal anomaly in the Bohai Bay Basin,and the basin was then in the stage of intense rift faulting at the ages of 46 to 40 Ma.The impulsive strike-slipping occurred in Altun fault at the ages of 43 to 35 Ma.The Baikal Lake rift came into being at the ages of 30 to 25 Ma.All the events outlined above are closely related to the cratering events in the Japan Sea.