RADIOCARBON VS. LUMINESCENCE DATING OF ARCHAEOLOGICAL CERAMICS IN THE SOUTHERN ANDES: A REVIEW OF PAIRED DATES, BAYESIAN MODELS, AND A PILOT STUDY

ABSTRACT Archaeologists have been using luminescence to date pottery in South America since the late 1970s, inspired by early success in northern Chile. However, luminescence dates have not been rigorously compared to independent dating methods, which this paper’s goal. First, we present a compilation of 94 paired 14C and luminescence dates from the southern Andes, which reveals discrepancies across a range of contexts and ages. Second, we compare two Bayesian models of sets of 14C and thermoluminescence (TL) dates from three ceramic styles in the Azapa Valley, Chile, and the Inca occupation of Mendoza, Argentina. We find that only the 14C models produce results that agree with expectations based on independent data. Third, we present results from a pilot study in Mendoza that dated 6 sherds with 3 luminescence methods each and closely associated 14C dates. The reasons for disagreement between methods remain unclear, but Andean sediments with low and unstable luminescence sensitivity seem to be an important factor. Even though some luminescence ages are accurate, the clear trend of inconsistent results leads us to recommend that archaeologists use 14C rather than luminescence dates to build cultural chronologies.

Editorial for Special Issue “Archaeological Ceramic Diagenesis”

In their seminal publication on neutron activation analysis of archaeological ceramics, Sayre, Dodson, and Burr Thompson [...]

The indigenous settlement of Monte Iato (western Sicily): an ethnoarchaeometric approach for outlining local Archaic ceramic productions

An ethnoarchaeometric approach has been followed to identify the textural and compositional characteristics of the ceramic pastes produced in ancient Iaitas/Ietas, an indigenous site located in western Sicily on Monte Iato, a few tens of kilometres from Palermo. This approach was primarily motivated by the lack of discovered Archaic kilns or production sites/workshops and the inability to identify reference groups. Raw clays were sampled in the territory of San Cipirello and San Giuseppe Iato (today’s municipalities both sited on the northern slopes of Monte Iato), together with representative historic tiles and bricks locally produced until fairly recently. Grain-size analysis and experimental firings were performed on the clay samples. A significant number of archaeological ceramic samples (incised and painted indigenous pottery dating back to the seventh–fifth centuries BCE) from stratigraphic excavations on Monte Iato, and hypothesized as local productions on a stylistic-morphological basis, was carefully selected for archaeometric analysis. This set of samples (90 in total, comprising raw clays, historic tiles/bricks and archaeological ceramics) underwent a combined chemical and mineralogical-petrographic analysis to identify any possible compositional matching. This approach enabled the identification of minero-petrographic and chemical markers pertinent to the indigenous Archaic pottery produced at Monte Iato, although no evidence of coeval ceramic kilns has been found so far. Local raw clay sources have been documented and some significant points of the chaîne opératoire adopted in antiquity have been noted (clay mixing and tempering practices). Attesting Monte Iato as a centre of ceramic production and defining both the microscopic fabric and the average composition of local pastes open up new perspectives in the complex issue concerning the production and regional circulation of incised and painted indigenous ceramics in Archaic Sicily.

Geochemical analysis of colonoware and brick artifacts from Brook Green Plantation using portable X-ray fluorescence spectrometry

This study used data collected using a portable X-ray fluorescence spectrometer to examine ceramic artifacts found during the excavation of historic Brook Green Plantation, in Georgetown County, South Carolina. Excavations at this site yielded culturally significant artifacts associated with African and African American people held in bondage during the 19th century. The geochemical composition of Colonoware and brick artifacts was compared to clay samples that were taken from six locations on the grounds of Brookgreen Gardens. Some Colonoware sherds were found to be consistent with a clay source close to the excavation site. This research is part of a larger goal to demonstrate the applicability of portable X-ray fluorescence spectrometry in the analysis and interpretation of archaeological ceramics.

Post-Depositional Alteration of Calcium Carbonate Phases in Archaeological Ceramics: Depletion and Redistribution Effects

The final stage in the life history of prehistoric pottery prior to archaeological recovery is usually the longest, and frequently the most dynamic. The remains of archaeological ceramics spend hundreds to thousands of years deposited within the upper layers of the earth’s crust where they encounter the same diagenetic environmental processes as the surrounding natural materials. Harsh conditions of subterranean environments induce physical stresses and chemical reactions, causing alterations of ceramic structure and composition. This is especially true of carbonate-rich ceramics, as carbonate phases are soluble when deposited within acidic environments. This paper examines common carbonate depletion and accretion effects of post-depositional environments on ancient ceramics from two rather different geological and archaeological contexts: Mesoamerica and the Mediterranean. Potters in both regions produce vessels with carbonate-rich materials—clays, calcite, limestone—that alter due to long exposure to low-pH sediments and continual water table fluctuations. Ceramic petrography is employed to identify traces of carbonate alterations within ceramic microstructure and to characterize fabrics. Elemental compositions of the same sherds are characterized through either scanning electron microscopy coupled with energy-dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry and optical emission spectrometry (ICP-MS/OES) or neutron activation analysis (NAA). This method enabled comparison of the differing effects of post-depositional alteration of carbonate phases on bulk composition signatures commonly used to determine provenance.

Working with huacos: Archaeological ceramics and relationships among worlds in the Peruvian North Coast

This article proposes a multitemporal approach to the study of archaeological ceramics in the Peruvian North Coast through archaeological ethnography. It allows us to create a new perspective of a past that seems to be continuously brought back in the ritual practices of curanderos (shamans), and in the daily life of other subjects that interact with what archaeologists call archaeological artifacts. In the rituals of curanderos and in the practice of huaqueo, where archaeological ceramics are known as huacos, it is possible to see how these vessels come to life, performing within a complex meshwork of relationships which extend over different worlds, as well as human and other-than-human participation. This discussion provokes the reevaluation of the relationships among archaeological heritage, archaeological material, and archaeological practice itself. It also shows how past and present are related in this specific Andean context.