资源环境科技发展态势分析平台

The behaviors between δ¹³C_benthic and δ¹⁸O_benthic are anti-phased after 6 Ma, and many mechanisms have been proposed to explain their behaviors. However, this question remains debated. Here, we reconstruct the interaction between mineral dust, global carbon cycle changes and the climate-cryosphere since 4 Ma. Our results suggest that Asian and/or global dust fluxes may have transported the signal of periodic Arctic ice sheet variability to the deep-sea δ¹³C_benthic record by mediating the strength of oceanic biological pumping. This can explain why δ¹³C_benthic data show very similar orbital-scale variability to δ¹⁸O_benthic changes controlled by Arctic ice sheet variability. A sharp increase in global dust fluxes after 1.6 Ma resulted in a significant weakening of the 405 kyr long eccentricity variance in δ¹³C_benthic data. We propose that mineral dust may have been one of the most important factors controlling the anti-phase relationship between δ¹³C_benthic and δ¹⁸O_benthic over the past 6 million years.