Abstract:

Tectonic structures within Anhui Province can be divided into three tecto-nic units of the first order on the features of geology and geophysical field,i.e.part of the Huabei platform,part of Yangtzi paraplatform and part of Qinling fold belt.A lot of Meso-Cenozoic continental depressions developed there.Their main characteristics are as follows:the formation was controlled by faults,sometimes related to basements.The shape is predominantly half-graben,the formation age ranges from Jurassic to Cretaceous or Cretaceous to Early Tertiary.In these depressions,the sedimental facies are mainly shallow lacustrine and fluvial sediments,though sometimes moderately deeper water to deep water lacustrine sediments might take place near the major fault.It is suggested that,although there are a lot of Meso-Cenozoic sedimentary depressions,and dark argillaceous rocks occasionally found in these depressions are thick enough,most of them are beyond the threshold of oil generation.The most prospective one is Jinhu-Lai'an depressoin,while the others,such as Nanling depression,the east part of Hefei,Guzheng and Zhoukou depressions might also exhibit some oil and gas potential.