关键词: 夭折大洋盆地, 构造演化, 充填特征, 大地热流, 地温梯度, 深水油气勘探, 双峰盆地, 南海

Abstract:

The aborted oceanic basin is a special basin generated during basin evolution from epicontinental rift to ocean basin. This kind of basin is characterized by formation of the oceanic basement, which stopped expanding later and switched to depression. The tectonic evolution period of this type basin includes 3 stages of epicontinental fault subsidence, oceanic basement expanding and depression. The formation generated during the period of epicontinental fault subsidence belongs to the continental facies distributed near the margin of the basin. The formation formed during the period of oceanic basement expanding belongs to the hemipelagic or pelagic deposit, which passively overlapped upon the prior layer from the brim to expending center of the basin. The formation formed during the period of depression belongs to deep-sea plain deposit and deep-sea mudstone. The aborted oceanic basin has higher geothermal heat flow and gradient, which are favorable to the organic material thermal evolution and result in the smaller hydrocarbon-generating threshold value. The aborted oceanic basin might become significant province of deep-water hydrocarbon exploration activity, because of good matching of source rock, reservoir bed and capping formation.

Key words: aborted oceanic basin, tectonic evolution, infilling characteristics, geothermal heat flow, geothermal gradient, deep-water hydrocarbon exploration, Shuangfeng Basin, South China Sea