Laure Dussubieux

The glass beads of Kaitshàa and early Indian Ocean trade into the far interior of southern Africa

Abstract The later African Iron Age saw a shift to centralised polities, as seen in the expansion of hegemonies such as Great Zimbabwe. During this period, trade with the interior of Africa became increasingly centrally controlled. Excavations at the site of Kaitshàa, on the edge of the Makgadikgadi saltpans in Botswana, have revealed how a small settlement based on prehistoric salt trading was able to take its place in the Indian Ocean trade network before such centralised polities arose. Using compositional analysis of glass beads, the authors argue that this site in the central Kalahari Desert exemplifies the role of heterarchy and indigenous agency in the evolving political economy of the subcontinent.

Recent Advances in Laser Ablation ICP-MS for Archaeology

This book explores different aspects of LA-ICP-MS (laser ablation-inductively coupled plasma-mass spectrometry). It presents a large array of new analytical protocols for elemental or isotope analysis. LA-ICP-MS is a powerful tool that combines a sampling device able to remove very small quantities of material without leaving visible damage at the surface of an object. Furthermore, it functions as a sensitive analytical instrument that measures, within a few seconds, a wide range of isotopes in inorganic samples. Determining the elemental or the isotopic composition of ancient material is essential to address questions related to ancient technology or provenance and therefore aids archaeologists in reconstructing exchange networks for goods, people and ideas. Recent improvements of LA-ICP-MS have opened new avenues of research that are explored in this volume.

Ile-Ife and Igbo Olokun in the history of glass in West Africa

Abstract Recent excavations at the site of Igbo Olokun in the Yoruba city of Ile-Ife, in south-western Nigeria, have shed light on early glass manufacturing techniques in West Africa. The recovery of glass beads and associated production materials has enabled compositional analysis of the artefacts and preliminary dating of the site, which puts the main timing of glass-working between the eleventh and fifteenth centuries AD. The results of these studies suggest that glass bead manufacture at this site was largely independent of glass-making traditions documented farther afield, and that Igbo Olokun may represent one of the earliest known glass-production workshops in West Africa.

The glass beads of Kampai Island, Sumatra

Pulau Kampai is the name of a small island on the east coast of Sumatra and also the name of a village on this island. Excavations conducted at Pulau Kampai in the mid-1970s yielded glass beads likely manufactured in India. More glass beads dating from the 11th to the 14th c. AD were found during excavations undertaken more recently. Those beads were analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Results show that the vast majority of the beads were likely imported from South Asia. Trace element signatures point toward two production areas: western India for most of the beads and northeastern India for a few high copper orange and red beads. A small number of beads have a very different composition resulting from the use of soda plant ash and a low alumina silica source indicating a possible Middle-Eastern provenance. A comparison with data published elsewhere indicates a similarity with material found in Egypt, dating from the 13th to the 15th c. AD suggesting that those beads might have reached the island during the later phases of the occupation period and might have transited through Egypt. It is uncertain where those beads were manufactured within the Middle-East. A comparison is provided with the glass beads from the site of Kampung Sungai Mas (9th to the 11th c. AD) located in Malaysia, one of the only “late” sites in the area that was studied recently using LA-ICP-MS.

Glass artifacts at Angkor: evidence for exchange

Although glass beads were found in large quantities in Southeast Asia during the Iron Age and into the first millennium CE, glass artifacts from the Angkorian period (ninth–fifteenth centuries CE) are less common and have not been as well-studied. This paper presents the results of an analysis of 81 glass beads and artifacts from the ninth-century royal capital of Hariharālaya and later (twelfth–fourteenth centuries CE) contexts from the walled city of Angkor Thom. Compositional analyses using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) have identified glass belonging to three broad compositional groups. The earlier Hariharālaya sites have numerous glass beads and vessel fragments made from vegetal soda glass, associated with Middle Eastern production, as well as high-alumina mineral soda glass of a sub-type frequently found at Iron Age sites in Southeast Asia and likely produced in South Asia. Beads from the later-period sites within Angkor Thom are primarily lead glass, associated with Chinese glass production, and different sub-types of high-alumina mineral soda glass that have also been found at sites in Southeast Asia dating from the fourteenth to the nineteenth centuries CE. A small number of beads from Angkor Thom also have a vegetal soda composition distinct from beads at Hariharālaya. The results of this study provide a new type of evidence for elite participation in broader regional exchange networks during the Angkorian period.

An empirical evaluation of copper procurement and distribution: elemental analysis of Scioto Valley Hopewell copper

In prehistoric North America, artifacts of copper occupy a position of prominence in the Hopewell societies of Ohio’s Scioto Valley. These artifacts also represent the social contacts and long-distance interactions that brought copper to the Scioto Valley. Yet, our understanding of Hopewell copper acquisition, and the movement of copper artifacts within the social networks of the Scioto Valley and beyond, has been limited due to the limited availability of geochemical data concerning provenance and variability. We begin to develop the foundation for understanding these important social issues by analyzing the elemental variability of Hopewell copper through the use of laser ablation inductively coupled plasma mass spectrometry. We analyze 24 samples from four known copper source regions and 52 samples from 6 prominent sites in the Scioto Valley. Results suggest that a majority of the artifacts are consistent with sources in the Great Lakes, with a plurality classified as Isle Royale. However, 21% of Scioto Hopewell copper artifacts were most consistent with southern Appalachian sources. High elemental variability argues against simple models of copper acquisition and suggests that different social groups had access to a variety of copper sources through varying social networks. Native copper regardless of source seems to have been channeled along similar social and symbolic pathways. Our results suggest that instead of being derived from the struggle to access a specific source, value is derived from the social relationships represented by the copper and the connotation of exotic connection embodied in both style and material.

H Vessel and Bead Glass Chemical Compositional Analysis

In Essouk-Tadmekka Sam Nixon and a team of scholars present the first archaeological exploration of the southern Saharan town of Essouk-Tadmekka, in early Islamic times an important market centre on the trans-Saharan camel-caravan routes linking the Mediterranean and West Africa.

K Preliminary Chemical and Technical Analyses of Essouk Metal Artefacts

In Essouk-Tadmekka Sam Nixon and a team of scholars present the first archaeological exploration of the southern Saharan town of Essouk-Tadmekka, in early Islamic times an important market centre on the trans-Saharan camel-caravan routes linking the Mediterranean and West Africa.

Analysis of Non-siliceous Archaeological Materials by LA-ICP-MS

This chapter introduces some of advantages of using LA-ICP-MS to analyze non-siliceous materials (metals), highlighting the approaches utilized in the studies included in Part II of this volume.

A Proficiency Test for LA-ICP-MS Laboratories Analyzing Ancient Glass

LA-ICP-MS is now one of the most common methods used for glass analysis in archaeology, and has the potential to build large databases for comparison. However, the actual comparability of measurements generated in different laboratories has not yet been addressed systemically. Here, the results of a round-robin comparison test on two modern glass samples with compositions comparable to ancient glasses is presented. The test involved nine laboratories using a diversity of mass spectrometers and lasers, as well as different calibration protocols and standard reference materials. Measured values differ significantly between labs for some elements, reflecting differences in calibration and instrumentation. However, these differences do not cause overlap between the glass samples that might confuse provenance in archaeological studies, but are significant enough to make finer-grained assignments to individual glass batches difficult or impossible when comparing across different laboratories.