Morphometry of Middle Bronze Age palstaves by Discrete Cosine Transform

The Discrete Cosine Transform (DCT) is a Fourier-related transform widely used in signal processing and well suited to the analysis of open outlines. This method was applied here to evaluate the discrimination power of the inner lateral rib for two palstave populations dating from the Middle Bronze Age, excavated in northwest France. A corpus of almost 400 palstaves (bronze axes) of the Breton and Norman types was processed, and compared to specimens found at Sermizelles in Burgundy. The procedure is robust and produces a discrimination in good agreement with the traditional typology. Besides the definition of a ‘standard’ shape for each population, the morphometrical approach allows shape disparity, which is generally inaccessible to the naked eye, to be visualised and quantified. Shape disparity indicates that, contrary to previous assumptions, the bronze axes from the Sermizelles hoards cannot be explained as an assortment of Breton and Norman palstaves alone. We believe that this approach is quick, reproducible, and generalisable enough to be applied to a wide variety of artefacts from different periods, in order to clarify their typology and even their origin.     

Roman Rhine settlement dynamics evidenced by coin distribution in a fluvial environment (Oedenburg,Upper Rhine,France)

On the basis of archaeological and alluvial records, this paper presents the first spatial analysis of artefacts in relation to the evolution of the Rhine River, at the Gallo-Roman site of Oedenburg, during the first four centuries AD. The dataset consisted of several thousand Roman artefacts found by pedestrian prospecting over the last twenty years, over half of which were coins. This dataset was used together with high-resolution topography and geomagnetic mapping, to reconstruct settlement evolution, both on the terrace and in the floodplain. A comprehensive monetary chart has been compiled for the Oedenburg site, which highlights four major phases of settlement. These results provide a possible causal link connecting historical factors and alluvial events with intra-site evolution. Therefore, while changes observed during Phases I (until AD 68), II (AD 69 to AD 180) and III (AD 180 to AD 295) seem largely related to historical and societal events, Phase IV (AD 295 to AD 402) shows patterns of abandonment of the lower part of the floodplain that may well be related to an unusually humid period in the fourth century. These results are set in a broader context, from the Rhine catchment area to the Alps, and are in agreement with the wet conditions also documented in alluvial, lacustrine, geomorphological and palynological records in Germany (Lahn River, Lake Constance, Lake Nussbaumen, Kaisersthul area and the Black Forest). Studying the intra-site spatial distribution of artefacts with high temporal constraints, at a long-lived site with contrasted topography, opens new avenues for the detection of discreet events such as a higher water table, affecting only the lower zone.