PETROLEUM GEOLOGICAL SIGNIFICANCE AND CHARACTERISTICS OF CALEDONIAN PALEOUPLIFT IN THE SOUTHERN MARGIN OF EAST QINLING AND DABIE OROGENIC BELT

There is a inherited paleouplift in the Jianghan Plain area of the southern margin of East Qinling and Dabie Orogenic Belt during Caledonian period.The authors believe that the Ezhong(Central Hubei Province)paleocontinent named by predecessors is its concrete expression.It exists in Late Sinian-Middle Cambrian in time domain and mainly distributed in Shennongjia-Baokang-Jingmen-Jingshan of the northern Jianghan Plain area and its north on the plane.The Ezhong paleocontinent passes over the Qingfeng-Xiangfan-Guangji fault zone.Subsequently,successive development of paleouplift has controlled paleogeomorphic forms of higher in the north and lower in the south during Caledonian period in the middle Yangtze region.The results showed that the Caledonian paleo-tectonic could be divided into four different structural units(the graben-horst belt of the East Qinling;the northern uplift belt of the middle Yangtze;the middle slope belt of the middle Yangtze;the southern depression belt of the middle Yangtze).The Caledonian paleouplift was evident in control of Sinian-Lower Paleozoic reservoir conditions in the southern margin of East Qinling and Dabie Orogenic Belt.The Caledonian paleouplift was a favorable destination for the migration and accumulation of early liquid hydrocarbon,which is important target for petroleum exploration breakthrough of Sinian-Lower Paleozoic reservoirs in Jianghan Plain.