THE CHARACTERISTICS OF THE UNCONFORMITY ON THE TOP OF PRECARBONIFEROUS AND ITS CONSTRAINTS ON OIL/GAS BEHAVIONR IN TARIM BASIN

In this paper,the formation mechanism and regional occurrence of the unconformity on the top of Precarboniferous in Tarim Basin were studied,and then,its constraints on the migration and accumulation of oil/gas,and roles in the preservation or destruction of pools were disccused. As the result,fault-flod umconformities,flod unconformities and onlay unconformities are that which significantly controlled oil/gas behaviour. The unconformity onthe top of Precarboniferous,together with the permeable zones immediately adjoining it,could act as conduits for oil/gas migration the scondary reserviors by dissolution and the onlay sandstone over the uncoformity could be the sites of oil/gas accumulation.