Planktonic foraminifera are an important biochronostratigraphic tool and one of the main proxies used in paleoceanographic studies. Here we present the integration of quantitative analyses of planktonic foraminifera biostratigraphy, planktonic and benthic foraminifera oxygen isotopic data, and planktonic foraminifera radiocarbon ages in a biochronostratigraphic framework for the last 1.93 Ma of the western equatorial Atlantic. The ages of the biostratigraphic events derived from our records are consistent with previous works except for the highest occurrences of Globigerinoidesella fistulosa (~1.82 Ma; MIS 66), Globigerinoides obliquus (~1.48 Ma; MIS 49), Globorotalia tosaensis (~1.05 Ma; MIS 31), and G. viola (~0.34 Ma; MIS 10). The largest difference in age (~1.13 Ma) was found for the highest occurrence of G. viola. In addition, we describe for the first time in the equatorial and western South Atlantic the oldest Pleistocene Globorotalia menardii disappearance (D) and reappearance (R) events D5 (~1.79 Ma; MIS 64), R5 (~1.68 Ma; MIS 60), D4 (~1.05 Ma; MIS 30) and R4 (~0.96 Ma; MIS 26). Our records present a consistent difference in the ages of G. menardii D and R events compared to the North and South Atlantic. While the onset of D events occurs initially at high latitudes and later in the equatorial region, the timing of R events exhibit the opposite trend. The oscillations in abundance of the complexes Pulleniatina and Globorotalia crassaformis together with the species Globorotalia truncatulinoides and Globoconella inflata allowed the subdivision of the last 1.93 Ma into 20 subzones, substantially improving the biochronostratigraphic resolution for the western equatorial Atlantic.

浮游有孔虫是重要的生物年代地层学工具，也是古海洋学研究中使用的主要代表之一。在这里，我们展示了对西赤道大西洋最后 1.93 Ma 生物年代地层框架中浮游有孔虫生物地层学、浮游和底栖有孔虫氧同位素数据以及浮游有孔虫放射性碳年龄的定量分析的整合。除了Globigerinoidesella fistulosa（~1.82 Ma；MIS 66）、Globigerinoidesobliquus（~1.48 Ma；MIS 49）、Globorotalia tosaensis（~1.05 Ma； MIS 31) 和G. viola（~0.34 毫安；MIS 10）。G. viola出现率最高的年龄差异最大（~1.13 Ma）。此外，我们首次在赤道和南大西洋西部描述了最古老的更新世Globorotalia menardii消失（D）和再现（R）事件 D5（~1.79 Ma；MIS 64）、R5（~1.68 Ma；MIS 60） , D4 (~1.05 Ma; MIS 30) 和 R4 (~0.96 Ma; MIS 26)。与北大西洋和南大西洋相比，我们的记录显示G. menardii D 和 R 事件的年龄存在一致差异。虽然 D 事件的发生最初发生在高纬度地区，后来发生在赤道地区，但 R 事件的发生时间却表现出相反的趋势。在丰富的复合物的振荡Pulleniatina和Globorotalia crassaformis连同Globorotalia truncatulinoides和Globoconella inflata允许将最后的 1.93 Ma 细分为 20 个亚区，显着提高了西赤道大西洋的生物年代地层分辨率。