Chemical analyses of ancient anthrosols in residential areas at Piedras Negras, Guatemala

Recent chemical analyses of ancient anthrosols in Mesoamerica and elsewhere demonstrate the explanatory value of these investigative techniques and al so point out some of the problems that challenge interpretive capabilities. This paper presents the results of phosphate and heavy metals analyses of soils in residential areas at Piedras Negras, Guatemala, and offers some pr eliminary interpretations of the patterns obtained. After a brief review of recent studies of soils in archaeological contexts, we discuss some of the merits and problems with using different sampling designs and with obtaini ng reference samples that help model distributions of chemical concentratio ns. To aid in interpreting domestic activities, soil analyses are combined with archaeological data produced from both large-scale clearing and smalle r test units. In this way, phosphate concentrations implicate refuse dispos al areas, and heavy metal signatures and their patterning suggest that urba n Maya houses may have been painted with metal-based mineral pigments. Vary ing, relative proportions of phosphates and heavy metals in midden deposits indicate the probability of classifying such features according to chemica l signatures. We argue that this combined approach offers greater clarity i n discerning activity patterns in residential environments than investigati ons that do not incorporate soil chemical analyses.