Geological features and petroleum accumulation in the foreland basins in central and western China

There are abundant oil and gas resources in the foreland basins in central and western China.Many outstanding successes of petroleum exploration have been obtained recently in that region.However,the exploration activity is rare because of the complex geology in the foreland basins.A classical foreland basin overseas is a linear depression located between the active orogen and stable craton.Nevertheless,in central and western China,there are mainly rejuvenated foreland basins resulting from convergence within the craton,related to the reactivation of old Tethys tectonic domains during the new Tethys stage.Therefore,there are many differences in comparison with the classical foreland basin abroad.The difference,due to the superimposition of foreland structures of two periods,is responsible for differences in basin geometry,in plate flexure and subsidence,in sedimentation,and in structural deformation.According to these differences,we have classified the foreland basins in central and western China into four types,i.e.,alteration foreland basin,palingenetic foreland basin,superposition foreland basin and caduceus foreland basin.They have different structural characteristics that determine the different reservoir features and the variable exploration potential for these three types of foreland basin.