Abstract:

Three topics are discussed in this paper as follows：(1)unconformity analysis and its significance in the study of basin formation and evolution;(2)unconformity analysis and its relation with intensity of tectonic movement and basin modification;(3)types of stratigraphic traps related with unconfomities.From above mentioned discussions,it is concluded that:(1)nomal cycle and on lap above unconfomity were occurred at extensional and neutral tectonic settings,where as revers ecycle,offlap and truncation unconformity were developed at compressional tectonic environments;(2)composite,progressive and syntectonic unconformities are related to accelerated and lessened uplifts in the margin of intracontinental foreland basins;(3)based on the structural deformations below truncation unconformities and eroded thickness of strata,the degree of basin modification resulted from tectonic movement,and the types of stratigraphic traps related to unconformities can be recognized．

Key words: onlap, offlap, truncation, composite progressive and syntectonic unconformity, ；tectonic movement, stratigraphic trap related to unconformity