生物礁沉积是南海乃至西北太平洋重要的沉积类型之一。本文利用新近钻进取芯的南海西沙西科1井生物礁沉积,开展了详细的磁性地层学研究。结果显示,早中新世三亚组记录了跨度为C5Dn~C6An正极性时的生物礁沉积。在综合全孔年代学结果的基础上,划分出新近纪西沙地区生物礁生长、发育的3个阶段:>约16.5 Ma和<约13.5 Ma两个稳定堆积时期,以及16.5~13.5 Ma快速堆积的“中中新世跃迁事件”。此外,本文推测西沙地区生物礁初始发育的时间显著早于过去认为的约20 Ma,同时三阶段的演化模式可能与南海扩张-结束的构造环境密切关联。 Reef deposition is one of the most important sedimentary types in the South China Sea and the Pacific Northwest. In this paper, the newly reef sediment coring in the South China Sea Saxikike 1 wells, carried out a detailed study of magnetic stratigraphy. The results show that the Early Miocene Sanya recorded the reef deposition at the positive polarity of C5Dn ~ C6An. On the basis of the comprehensive geochronology results, three stages of reef growth and development in the Xisha area of ​​Neogene are divided:> about 16.5 Ma and