南海边缘海构造旋回对沉积充填的控制——以礼乐盆地新生代沉积为例

礼乐盆地是在南海边缘海构造旋回控制下形成的沉积盆地,受古南海消亡与新南海扩张影响,盆地自晚白垩世以来经历了晚白垩世-早渐新世漂移前、晚渐新世-中中新世漂移和晚中新世-现今漂移后共3期区域演化阶段。古新世-早渐新世,礼乐盆地以滨浅海沉积为主,主要发育三角洲-扇三角洲-水下扇-盆底扇-滨海-浅海沉积体系;晚渐新世-中中新世,沉积物源供给缺乏,以滨浅海和半深海沉积为主,盆地北部发育大型碳酸盐台地;晚中新世以来,沉积物源主要来自盆地东南侧及内部火山,发育水下扇-浅海-半深海-碳酸盐台地沉积体系,以浅海和半深海沉积为主。礼乐盆地具有相对较好的烃源岩、有利的储集相带和良好的区域盖层,油气资源勘探潜力较大。

The control for tectonic cycle of marginal sea on sedimentary fill in South China Sea:a case study of Cenozoic sediment in Lile Basin

Lile Basin is a sedimentary basin formed under the control of the tectonic cycle of marginal sea in South China Sea. Influenced by the disappearance of Paleo-South China Sea and the expansion of New South China Sea, Lile Basin has undergone three regional evolution since the Late Cretaceous, i.e., the stage prior to Late Cretaceous-Early Oligocene drifting, the Late Oligocene-Middle Miocene drifting stage, and the stage posterior to Late Miocene-current drifting stage. In the Paleocene-Early Oligocene, Lile Basin was dominated by littoral-neritic sediments, where the delta-fan delta-submarine fan-basin floor fan-littoral-neritic sedimentary system was mainly developed. In the Late Oligocene-Middle Miocene, due to lack of sediment provenance, Lile Basin was dominated by littoral-neritic and bathyal sediments, where a large-scale carbonate platform was developed in the northern basin. Since the Late Miocene, sedimentary provenances were mainly sourced from the southeastern basin and internal volcanoes, where the submarine fan-neritic-bathyal-carbonate platform sedimentary system was developed and mainly made up of neritic-bathyal sediments. Lile Basin has relatively good source rocks, favorable reservoir facies belts and regional caps, indicating a huge hydrocarbon resource potential.