TECTONIC EVOLUTION AND HYDROCARBON DISTRIBUTION IN NORTH CHINA BASIN

Since Mesozoic,the platform of east China had been transformed to active continental marginal belts.Structural units of faulted upwarping,falldown depression,platform folding belts had been formed through tectonic deformations during Indo-chinese,Yanshan and Himalaya periods.Under stretching force,north China basin formed itself into a tensional falldown basin.The conditions for oil generation were different due to basemental structure and subsidence rate.There are three stages of structural evolution for tentional basin,relative to basin development are early period of faulted subsidence,filling period of faulted subsidence and regional depressing period.Three stratified structures,i.e hydrocarbon pool in burial hills,original hydrocarbon pool and draped hydrocarbon pools were developed.Hydrocarbons were mainly accumulated in the pools capable of self generation and preservation,from lower Tertiary of filling period of faulted subsidence.