Mineral Dust Coupled With Climate‐Carbon Cycle on Orbital Timescales Over the Past 4 Ma
Mengmeng Cao, Zhixiang Wang, Yu Sui, Yanzhen Li, Ze Zhang, Anguo Xiao, Rui Zhang, David B. Kemp
Abstract
Abstract The behaviors between δ 13 C benthic and δ 18 O 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 climate‐cryosphere system 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 δ 13 C benthic record by mediating the strength of oceanic biological pumping. This can explain why δ 13 C benthic data show very similar orbital‐scale variability to δ 18 O 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 δ 13 C benthic data. We propose that mineral dust may have been one of the most important factors controlling the anti‐phase relationship between δ 13 C benthic and δ 18 O benthic over the past 6 million years.