Obsidian provenance analyses at Göytepe,Azerbaijan: Implications for understanding Neolithic socioeconomies in the southern Caucasus

This study presents a provenance analysis of the Neolithic obsidian assemblages from the early to mid‐sixth millennium bc settlement at Göytepe, Azerbaijan. The study is unique in that (1) it involves a complete, non‐selected obsidian assemblage (901 artefacts) from one particular area of the site; (2) the material is derived from a well‐stratified sequence of 10 securely radiocarbon‐dated architectural levels; and (3) the use of an extraordinarily wide range of sources (more than 20) was identified by provenance analysis using energy‐dispersive X‐ray fluorescence. The results reveal a previously unknown diachronic change in obsidian use in the region, suggesting the occurrence of significant socioeconomic changes during the Late Neolithic of the southern Caucasus.     

The Chronology of Insiza Cluster Khami‐Phase Sites in South‐Western Zimbabwe: Compositional Insights from pXRF and Raman Analysis of Excavated Exotic Glass Finds

Fourteen glass beads and one glass fragment from Khami‐period (ad 1400–1830) sites of Danamombe, Naletale, Gomoremhiko, Nharire and Zinjanja, in Zimbabwe, were analysed by pXRF and Raman spectroscopy with the intention of correlating the results with associated radiocarbon dates. The results show that Zinjanja and an earlier part of the Danamombe stratigraphic context had Khami Indo‐Pacific beads (15th–17th centuries) corresponding with Torwa occupational layers. Other European beads and one bottle fragment [high‐lime, low‐alkali (HLLA) glass] dating from the 16th to the 19th centuries were confined to the top stratigraphic layers of Danamombe and Naletale, which coincide with the later Rozvi occupational layers. Gomoremhiko had one Mapungubwe–Zimbabwe bead series (13th–15th centuries), which suggests that it was probably earlier than the other sites. All European beads are made of soda–lime plant‐ash glass with high alumina, which makes them comparable with glass produced through the Mediterranean traditions in Southern Europe.     

Geochemical analysis of Late Classic and Post Classic Maya marketplace activities at the Plazas of Cobá, Mexico

Abstract

Lines of evidence for ancient exchange plazas may include trade routes and trade artifacts, urban open space near public structures, and rock alignments denoting market stalls, but regular patterns in soil chemical concentrations also point to marketplace use. We applied geochemical and geospatial analysis of the floors of the main Plaza of Group B and Plazas A, H, and J of Group D at Cobá, Mexico, to discover the chemical residues of phosphorus (P) and metals associated with the exchange of foodstuffs and mineral workshop items that may have been marketed there. The patterns of chemical residues in the floor of the Group B Plaza suggest ritual activities while the linear, parallel patterns of elevated Mehlich phosphorus and chelate extractable zinc concentrations in Plaza A support the hypothesis of market exchange at that location. Plaza H is associated with several Postclassic buildings, including the Pinturas Structure D-33. During the Postclassic period, Cobá had lost much of its population, though chemical residues from Plaza H are congruent with marketing. We argue that Plazas A and H were not permanent marketplaces but rather multi-purpose locations that also hosted large ceremonies.     

Characterisation of obsidian subsource variability at El Paredón,Mexico

Portable X-ray fluorescence (pXRF) geochemical analysis on obsidian from five Formative period (1200 BCE to AC 100) sites from Tlaxcala, Mexico, has revealed that most of the material had similar values to those found in the closest obsidian source, named El Paredón, Puebla. Nevertheless, initial analyses did not resolve whether these materials came from the same caldera or from a specific obsidian deposit. Here we present a methodology that allows the identification of obsidian subsources. The results reveal that Tlaxcalan populations took advantage of a specific obsidian deposit called Tres Cabezas, Puebla, providing valuable new data to identify associated regional exchange networks.     

One Colour, (at Least) Two Minerals: A Study of Mulberry Rock Art Pigment and a Mulberry Pigment ‘Quarry’ from the Kimberley,Northern Australia

Distinctive mulberry paintings found in northern Australia, particularly those of the Kimberley region, have been argued to represent some of the oldest surviving rock art on the continent. Significant research efforts continue to focus on resolving the age of these motifs, but comparatively little attention has been given to understanding their physical composition and potential source(s). In a pilot investigation, we conclude that (at least) two mineralogically distinct mulberry pigments occur in Gwion motifs and demonstrate that their major components can be indicatively chemically differentiated, non‐invasively. Characterization of a ‘quarried’ mulberry ochre source demonstrates that these pigments occur locally as natural minerals.     

A case for lead-glaze experimentation by late eighteenth-century Catawba using portable X-ray Fluorescence (pXRF)

ABSTRACT

Recent research has demonstrated that Catawba ceramic practices changed abruptly and dramatically after 1759 following a devastating smallpox epidemic and subsequent community relocation. Pottery from the historically documented Catawba town of Old Town and others indicate potters adopted new techniques and styles as they adjusted to new economic and social conditions, including copying European vessel forms, experimenting with new ceramic paste recipes, and utilizing new decorative motifs. The identification of four lead-glazed sherds on otherwise Catawba-looking pale-bodied paste raises the possibility that Catawba potters may have also experimented with lead glazing. This paper presents the results of an elemental analysis of nearly 70 ceramic samples using pXRF and multivariate statistical techniques to identify patterns of production within pale-bodied colonowares. The results indicate that the glazed pottery fragments were made with elementally similar clay used by Catawbas in the Twelvemile Creek locality. I argue that in addition to modifying nearly every aspect of their ceramic repertoire, at least one Catawba potter experimented with lead glazing, providing further insights into the emergent Catawba pottery trade.