Domestic refuse and residential mound formation in La Mixtequilla, Veracruz, Mexico.

Abstract

The Mesoamerican residential mound is a basic unit of archaeological analysis. The way mounds form has implications for reconstructing past social organization. Studies of formation processes assume that characteristics of refuse are the result of depositional history. Tracing the history of archaeological deposits is the first step toward understanding the social and economic milieu of the prehistoric household. The traces of mound formation processes particularly are evident in ceramics. This study examines measures such as density, mean size, and variation in size and wear, to determine their utility in ascertaining depositional history, including discard practices, erosion, and trampling. The measures are tested with the Exploratory Data Analysis method using visual inspection of the data for patterns and examination of exceptional cases. Density by weight and mean sherd size were found to be particularly useful and simple measures for differentiating archaeological deposits. The characteristics of artifacts in a deposit provide the basis for reconstructing the formation of mounds. Earthen residential mounds like those of Veracruz are low and broad and usually lack imperishable construction materials. Unlike Maya housemounds, which often use fill for mound construction, earthen mound formation resembles (on a smaller scale) the formation of tells, the remains of ancient villages and towns in Western Asia. For both tells and earthen mounds, the erosion of houses forms the bulk of mound sediments. Residential mound growth is more by gradual accretion than by deliberate construction, and is due to six main formation processes. These are: (1) the erosion of wattle-and-daub construction material, which contribute to mound sediments; (2) the gradual accretion of sediments and artifacts; (3) horizontal erosion of daub and artifacts; (4) secondary refuse deposition; (5) the occasional use of fill to expand or level the mound; and (6) the development of a humic topsoil layer commonly damaged by plowing. Through refuse characteristics it is possible to reconstruct mound growth, use of space, and the location of structures and refuse dumps. These formation processes distinguish earthen mound development in many parts of Mesoamerica.