The basement nature

the cover facies

the structural feature and magmatic activity in the lower Yangtze Region have presented obvious differentiae in the north and south parts of the region.The reason caused these differences is the existence of south (the Qiantang) and north (the Yangtze) terranes.These two terranes

under went long tectonicevolution

were connected as a unified composite terrane in the end of the Triassic.The Qiantang Terrane is the primary place for hydrocarbon generation and accumulation from Lower Paleozoic;the Yangtze Terrane is the most favourable place for thatfrom Upper Paleozoic (including the Middle and Lower Triassic).The former will be themain target for oil and gas exploration.