The characteristics of the unconformity surface of the Yaojia Group bottom and its relationship with hydrocarbon accumulation,western slope zone of Songliao basin

The unconformity surface at the bottom of yaojia group is of great importance to the petroleum migration at western slope area of songliao basin.From the systematic analysis of unconformity's characters,we found that the unconformity surface at the bottom of yaojia group developed parallel unconformity and angular unconformity.Vertical structure does not have the typical three-tier structure.The basal conglomerate layer and semi-weathered leaching layer is not common.The mainly matching type of the unconformity is sand on mud.At the basis of these findings,the paper discussed the relationship between the unconformity's characteristic and the petroleum's migration and accumulation.We think the angular unconformity have great positive correlation with the petroleum's migration and accumulation.Then we put out this point,the scope of unconformity's development is good for the exploring of trap which is correlated with unconformity.