Histories of deposition: creating chronologies for the Late Bronze Age-Early Iron Age transition in Southern Britain

The Late Bronze Age-Early Iron Age midden sites of Southern Britain are amongst the richest archaeological sites in the country. The organic accumulations contain substantial quantities of animal bone, decorated ceramics, metalwork and other objects; the often deep stratigraphy allows for changes in material culture and depositional practices, food production and consumption, and shifts in social identities, to be traced through time. The well-stratified assemblages also provide useful materials for dating the deposits. This has been problematic, however, as the majority of samples produce unhelpfully broad calibrated radiocarbon dates, due to the effects of the earlier Iron Age plateau in the calibration curve, which spans c. 800-400 BC. Interpretation has relied on current understandings of the associated pottery and metalwork, which placed most midden sites somewhere between the tenth and the seventh/mid-sixth centuries cal BC (c. 1000-600/550 cal BC), but the end-date of these traditions is particularly uncertain. This article addresses this issue by presenting the results of a new dating programme for East Chisenbury in Wiltshire, southern England. Twenty-eight radiocarbon determinations were obtained and combined with the site stratigraphy in a Bayesian chronological model. The results have transformed the chronology of the site, with the end of the occupation sequence being pulled forward some one-hundred years, to the mid-to-late fifth century cal BC. These new chronologies have significant implications for our understanding of the Late Bronze Age-Early Iron Age transition and require a revision of the currently accepted chronology of post-Deverel Rimbury decorated wares in south-central England.