Abstract:

Lower Yangtze Region is a composite hydrocarL,on-bearing area cmoposed of superposed multicyclic depositional body. The depositional body includes: marine sediments deposited on the stable Paleozoic and Middle-Lower Triassic: intermontane basin formed in Upper Triassic-Lower Cretaceous compressive environment: fault-depression formed in post-Late Cretaceous tensive environment. Two peak stages of oil generation could be determined in the evolution history of marine source rock. The first one was the Caledonian, and the source rock was Lower Paleozoic: the second one happened post-Late Cretaceous in Upper Paleozoic, Middle-Lower Triassic Systems. Three main pool-forming stages were Caledonian, Indosinian-Yenshan and Late Yenshan-Himalayan Periods. The pools formed in late Yenshan-Himalayan are most favourable targets for hydrocarbon exploration.