Table 2. Mean posterior probability proportions of geochemical source contributions to observed variation in Chaco maize.

	Pre 1140 A.D. Maize	Post 1140 A.D. Maize	Historic Maize
Chaco Watershed	0.127	0.145	0.128
Aztec Soil	0.131	0.114	0.135
Chuska Slope	0.120	0.098	0.119
Northwestern San Juan	0.110	0.076	0.121
Lobo Mesa	0.134	0.177	0.132
Red Mesa	0.119	0.094	0.122
La Plata	0.117	0.085	0.119
Salmon Ruin	0.143	0.211	0.125

For all maize samples, the strontium shows uniform mean posterior probabilities across all possible sources. This indicates a high degree of uncertainty when attempting to use strontium to source maize samples.