Fig 1.
Distribution of Stone Walled sites.
Map showing the distribution of stone-wall settlements in the second millennium CE in southern Africa (adapted from [1]).
Fig 2.
Stone walls in black were surveyed on the ground, stone walls in grey were manually digitised by S. Merlo from GoogleEarth imagery and not verified on the ground. The position of the control samples (black triangles) and sampling areas (red squares) are indicated. Sources: contour data and rivers extracted from Aster DEM by S. Merlo.
Fig 3.
View of the site of Seoke, October 2019 Stone Walls at Seoke, southern cluster.
Cenchrus ciliaris (buffalo grass) can reach 1,5 meters in height.
Fig 4.
Map of the sampled areas at Seoke northernmost cluster showing detail of the features recognised during ground survey.
The features discussed in the paper are numbered in a progressive way: enclosure 1 (e1), midden 1 (m1) and midden 2 (m2) in area A; midden 3 (m3) and enclosure 2 (e2) in area B; stone wall 1 (sw1) and midden 4 (m4) in area C.
Table 1.
Summary statistics of the raw values for archaeological and control samples.
Correlation coefficients can be found in S2 File.
Fig 5.
Unweighted Logratio Analysis (LRA) biplot of samples, with 95% confidence ellipses for the feature types (enclosure 2 has been excluded).
Fig 6.
Co-Kriging map of elemental concentration at Seoke at areas A-C.
Values express absolute concentrations (in %).
Fig 7.
Logratio Analysis (LRA) including the control samples (labeled).
Blue dots correspond to the “archaeological” samples.