根据东沙隆起及其周围钻井资料的一维构造沉降对比分析,结合前人在基底、盖层及断裂等方面的研究,将东沙隆起地区的构造演化分为5个阶段:白垩纪挤压阶段、古新世-早渐新世伸展断陷阶段、早渐新世末期抬升剥蚀阶段、晚渐新世-中新世快速的裂后沉降阶段、晚中新世以来断块升降阶段。认为下地壳高速层是促使早渐新世末期抬升剥蚀的重要因素,而与高磁异常带、磁静区没有密切的联系。
Based on the 1-D tectonic subsidence analysis of Dongsha rise and adjacent area,combined with the previous researches on basement,faults,subsidence,it is proposed that the tectonic evolution history of Dongsha rise can be divided into five stages:compression setting in Cretaceous;initial extension in Paleocene to early Oligocene;denudation at the end of early Oligocene;quick thermal subsidence in later Oligocene to Miocene;fault block adjustment from later Miocene.The high velocity layer in the lower crust is the main cause of the Dongsha rise uplifting and erosion in the early Oligocene,but it has no appavent relationship with magnetic quiet zone and high magnetic zone.