MARINE PALEO-MESOZOIC HYDROCARBON SOURCE ROCKS ON LAND OF THE LOWER YANGTZE PLATFORM AND THEIR IMPLICATIONS FOR OIL AND GAS EXPLORATION IN THE SOUTH YELLOW SEA BASIN

Field studies have been made for 25 outcrops in the region around Nanjing, Chaohu and Zhejiang, in addition to a thorough review of collected data and references. Six regional hydrocarbon source rocks are recognized on land of the lower Yangtze platform, which include the Lower Cambrian Hetang Formation, Lower Ordovician Ningguo Formation (Dawan - Guniu), Upper Ordovician Wufeng -Lower Silurian Gaojiabian Formation, Lower Permian Qixia Formation, Upper Permian Longtan and Dalong Formations. The development of hydrocarbon source rocks is controlled by many factors. In the Yangtze region they include mainly the tectonic evolution, maximum flooding surface, ancient geomorphology, sedimentary environment etc. The tectonics and maximum flooding surface control the stratigraphic horizons of hydrocarbon source rocks, the paleogeomorphology controls the distribution of hydrocarbon source rocks, and the depositional environment controls the types of hydrocarbon source rocks. The research results on land of lower Yangtze platform may provide a basis for comparison in the South Yellow Sea Basin