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

Abstract

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 a number of 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.

Problems of Dating Spread on Radiocarbon Calibration Curve Plateaus: The 1620–1540 BC Example and the Dating of the Therasia Olive Shrub Samples and Thera Volcanic Eruption

“…However, as illustrated in a range of recent work, and this Therasia case study again highlights, various method strategies using informative priors, as relevant or bespoke to the particular samples and context(s) involved, are now available that much better enable chronological resolution via Bayesian Chronological Modeling for contexts that lie at the time of plateaus in the radiocarbon calibration curve (e.g. Manning et al 2018a;2018c;2019;2020a;Waddington et al 2019;Meadows et al 2020;Birch et al 2021;Rose et al 2022;Manning and Birch 2022). With increasing radiocarbon measurement accuracy and precision as standard via rigorous sample pretreatment and modern AMS 14 C analysis, and a better (ideally annually informed) radiocarbon calibration curve adding resolution (as already in the period 1700-1500 BC discussed in this paper), the application of such methods promises increasingly to allow high-resolution dating on plateaus almost as effectively as on slopes in the radiocarbon calibration curve.…”

“…tree-ring series) or typological information, and/or (ii) prior knowledge of total sequence length and/or of any intra-sequence associations (e.g. Waddington et al 2019; Meadows et al 2020; Manning et al 2020a; Manning and Birch 2022; Rose et al 2022). In the absence of such forms of additional constraints, sequences of dates on a plateau will end up defining too wide a calendar age range and will likely end up suggesting dating probability that is either too old or too recent.…”

Dividing time—An absolute chronological study of material culture from Early Iron Age urnfields in Denmark

“…Recent studies using Bayesian chronological modelling have demonstrated that is possible to model case studies on 14 C calibration plateaus, although applications tend to target materials whose dates are constrained by strong prior information based e.g. on stratigraphy [52,53], floating tree-ring series [54,55], or archaeogenetic evidence [56]. This study however employs relatively weak constraints, assuming that artefacts sharing certain characteristics (i.e.…”

The Ambivalent Dead: Curation, Excarnation and Complex Post-mortem Trajectories in Middle and Late Bronze Age Britain

“…At East Chisenbury, Wiltshire, recent excavations of the enclosure ditch surrounding the well-known midden, as well as post-holes and other features immediately adjacent to it, produced several fragments of human bone (Andrews 2021; for discussion of the overall date range of the midden itself, see Waddington et al 2019). The disarticulated ulna of a child aged 8-12 was deposited in the enclosure ditch (middle fill 128).…”