Figure 3
From: Accumulation of radiocarbon in ancient landscapes: A small but significant input of unknown origin
Keeling plots and a two-endmember isotopic mixing model to measured Δ 14C values of bulk paleosol samples. (A) A Keeling plot approach to estimate the 14C signal of the old-carbon endmember of two paleosol profiles where the 14C signal of the “old” carbon endmember is the y-intercept; (B) the relationship between fraction modern (FM) values from bulk samples and the modelled abundance of modern organic carbon. We assumed a Δ 14C value of 0‰ for modern carbon; model outputs for Δ 14C of 300‰ and 600‰ for modern C were also considered and are listed in Table S4.
