Fig. 5: Results of the isotope analysis of P. spiralis endocarp, compared to isotope analysis of soil, and stone artefact and exotic raw material discard by depth.
From left to right: soil profile; δ13C values of archaeological P. spiralis endocarp from Square C3 grouped by phase and displayed by mean depth of contexts; predicted MAP at Madjedbebe, based on the mean δ13C values of archaeological P. spiralis endocarp and the modern relationship between δ13C and MAP (Fig. 3c), with 95% confidence interval (grey area) and 95% prediction intervals (dashed lines); δ13C of archaeological soil organic matter samples from Square B2, taken at ~5-cm intervals and grouped by phase; number of lithic artefacts per litres floated for Squares E1 to B3 by depth; number of lithic artefacts produced from exotic raw materials per litres floated for Squares E1 to B3 by depth. Dashed lines on the second, fifth and sixth panels are locally estimated scatterplot smoothing (loess) curves. The data and R code for this figure are available from ref. 54. Soil profile in the left panel adapted with permission from ref. 1, Springer Nature Ltd.
