关键词: 断陷盆地, 喷出岩标定法, 断层, 油气运移, 深县凹陷

Abstract: The volcanic eruption often resulted in the effusive rocks in the rifted basin.The effusive rock is a special lithologic unit and has the same space-time distribution with the earthquakes and fault activities.The effusive rock often stands for the in-situ sediment and contains the age message.Based on the characteristics of the effusive rock,a new method called as effusive rock calibration method for studying the period of oil migration was proposed.Firstly,the position and time of fault activities were determined by studying the space-time distribution of effusive rocks.Secondly,the effective fault for oil-gas migration could be identified in combination with the mature period of source rocks.Supposing the deposition rate was changeless during this period,the time of oil migration could be determined by researching the burial depth and effusive stage of the effusive rocks near fault.This method can be applied in rifted basin with abundant effusive rocks.This method was used to determine the hydrocarbon migration period of source rocks in the third section of Shahejie Formation of Shenxian Depression.The oil migration period in first stage ranged from 21.1Ma to 23.37 Ma before present.

Key words: rifted basin, effusive rock calibration method, fault, hydrocarbon migration, Shenxian Depression