深海钻探揭示构成环礁的浅水碳酸盐建隆覆盖沉积在太平洋西北部平顶海山之上。相对于现今珊瑚藻类生物构成的环礁而言,白垩纪和古新世孤立的环礁的四周边缘生物含量甚少,造礁能力下降。这些环礁浅水碳酸盐沉积在火山基座的顶部,在Albian初期、Albian末期、Maastrichtian晚期和始新世中期发生沉没。早期研究认为这些碳酸盐体系经历了地面暴露阶段以及随后的海侵淹没阶段。然而,一个事实是,环礁沉没仅发生在当太平洋板块背负着平顶海山向北漂移过程中,并且是经过南纬7°以后。几个不同的假说用来解释该时期环礁沉没现象,包括环礁暴露、喀斯特化、地面侵蚀、增强赤道上升洋流、缺氧和/或者富营养的浑浊水的出现等。文中在太平洋平顶海山深海钻孔的沉积、生物地层和古纬度数据综合研究基础上,提出一种新模式用于解释晚白垩世—古新世浅水碳酸盐建造的沉没。与以前的模式不同的是,文中提出,这些晚白垩世—古新世“环礁”之所以发生沉没,原因是受到原始环南赤道洋流(pSEC)的影响,导致一种对分泌碳酸盐的生物不利环境的产生。而且,当这些平顶海山漂移到南纬5°时,即赤道古纬度带,许多浅水碳酸盐建造之上,铁锰结核开始沉积。同时,平顶海山下沉到溶解氧极小层(海平面之下400~1 100 m)和原始环南赤道中层洋流( pEI Deep-sea drilling reveals that shallow-water carbonate enclaves that form atolls overlie the Pingdingshan Mountains in the northwest Pacific Ocean. Compared to the atolls formed by coral algal organisms today, Cretaceous and Paleocene isolated atolls have very low biota and low reef-building abilities. These atolls were deposited on top of volcanic pedestals, beginning with the early Albian, late Albian, late Maastrichtian and mid-Eocene sediments. Earlier studies suggested that these carbonate systems underwent the stage of surface exposure and subsequent submergence of transgression. However, the fact is that the atoll submergence occurs only when the Pacific plate is carrying a flat-top seamount drifting northward and after 7 ° south latitude. Several different hypotheses are used to explain atoll submergence during this period, including atoll exposure, karstification, ground erosion, increased equatorial upwelling, the presence of hypoxia and / or nutrient-rich turbid water. Based on a comprehensive study of deep-sea drilling deposits, biostratigraphy and paleo-latitude data from the Pingdingsha Sea in the Pacific Ocean, a new model is proposed to explain the subsidence of the Late Cretaceous-Paleocene carbonate reservoir. Unlike previous models, the paper suggests that the sub-cretaceous-Paleocene “atolls” subsided due to the influence of the pristine southern equatorial current (pSEC), resulting in a sequestration of secreted carbonates The biological adverse environment generated. Moreover, when these flat-top seamounts drift to 5 ° S, the ancient equatorial latitudes, many shallow-water carbonates are built and ferromanganese nodules begin to deposit. At the same time, the Pingdingshan subsidence to very small layer of dissolved oxygen (400 ~ 1 100 m below sea level) and the original Central South Equatorial Ocean Current (pEI