Abstract:

Qianzhong uplift and its periphery are located in passive continental edge of south-eastern part of Upper Yangtze Plate in Early Paleozoic, which has experienced five evolution stages such as the stage to form pre-Sinian base，the stage of rift in Early Sinian,the stage of passive continental margin basin from Late Sinian to Silurian, the stage of continental rift and craton basin from Devonian to Mid-Triassic and the stage of continental basin from Late Triassic to Eogene, possessing favorable geological conditions to generate oil and gas. There develop two sets of regional oil-generating strata:muddy shale of Doushantuo Formation of Upper Sinian and muddy shale of Niutitang Formation of Lower Cambrian as well as muddy shale of Meitang Formation of Lower Ordovician and muddy shale of Longmaxi Formation of Lower Silurian, regional hydrocarbon source rocks have great ability to generate hydrocarbons. There develop reservoirs as dolomites of Dengying Formation of Upper Sinian, clastics of Jingdingshan Formation of Cambrian, carbonates of Gaotai Formation and Loushanguan Formation as well as Lower Ordovician-Lower Silurian, while mudstones of Niutitang Formation and gypsum dolomites of Loushanguan Formation as well as coal mudstones of Longtan Formation of Lower Permian are regional cover rocks in this area, they are also the regional cover rocks of Meitan and Longmaxi formations. Preserving conditions are very complicated and Yanshan and Xishan movements are the main controlling factors for the formation of oil accumulation. According to these studies, this area has great potential for natural gas exploration. Anshun Depression, Santang-Baixin Depression and Qianxi Depression,which have better regional preserving conditions,are the most favorable belts for natural gas exploration.

Key words: exploration potential, Lower Paleozoic, structural-sedimentary evolution, regional preserving condition, Qianzhong uplift