Planktonic foraminiferal geochemistry and assemblage data from sediment core CDH-89 (western equatorial Atlantic) during the penultimate deglaciation@en

We apply a multi-proxy approach to marine sediment core CDH-89 (western equatorial Atlantic, WEA) to investigate ITCZ variability during the penultimate deglaciation. Planktonic foraminiferal assemblages were used to calculate the RN/Gg ratio, defined as %Neogloboquadrina / (%Neogloboquadrina + %Globigerina glutinata), providing insights into upper-ocean structure. We further reconstructed surface hydrography using a suite of oxygen-isotope–based proxies, including Neogloboquadrina dutertrei δ¹⁸O, Globigerinoides ruber (white, sensu stricto) δ¹⁸O, and the interspecies gradient Δδ¹⁸O (N. dutertrei – G. ruber). In addition, we estimated seawater isotopic composition (δ¹⁸O_SW) for both species (N. dutertrei δ¹⁸O_SW and G. ruber δ¹⁸O_SW), as well as the interspecies difference Δδ¹⁸O_SW (N. dutertrei – G. ruber), to infer past salinity variations. Sea-surface temperature was reconstructed using N. dutertrei Mg/Ca-derived calcification temperatures, and we calculated the interspecies temperature gradient ΔTemperature (N. dutertrei – G. ruber) to provide additional constraints on upper-ocean thermal structure.