Anthropic activity markers and spatial variability: an ethnoarchaeological experiment in a domestic unit of Northern Gujarat (India)

Spatio-temporal understanding of past domestic activities is a key aspect of archaeological reasoning. The identification of markers of particular anthropic actions through time has become a fundamental issue. Chemical analyses of archaeological floors are an essential tool to investigate and identify anthropic markers of past human activities. This paper explores the relative spatial variability of chemical residues of floors in an ethnographic context to provide a constructive basis to experiment with spatial analysis for the detection and interpretation of anthropic activity markers. These markers are recognised as anomalies and tendencies in the relative spatial distribution of chemical residues embedded in the floor. The experiment has been carried out in a controlled environment and serves to test the methods and assumptions to be used in archaeological contexts. Spatial interpolations (IDW, Map Algebra and PCA) were performed and allowed the identification of anomalies in the distribution of residues that can be associated with specific activities (fuel use, food preparation and consumption, use of fireplaces). Geostatistics (Ordinary and Regression Kriging) was used in order to contribute to the identification of trends related to the use of space and the connected activities (e.g. inner versus outer space, storage versus cooking). The results show how the integration of different techniques can improve data interpretation.