Prehistoric copper production and technological reproduction in the Khao Wong Prachan Valley of Central Thailand

This paper concerns the identification and explanation of change in prehistoric extractive metallurgical behaviour in the Iron Age Khao Wong Prachan Valley of central Thailand. This metallurgical complex is amongst the largest in Eurasia and constitutes Southeast Asia's only documented pre-modern copper-smelting evidence. The two Iron Age smelting sites investigated, Non Pa Wai (NPW) and Nil Kham Haeng (NKH), provide a sequence of metallurgical consumption and production evidence from c. 500 BCE to c. 500 CE. The enormous quantity of industrial waste at these sites suggests they were probably major copper supply nodes within ancient Southeast Asian metal exchange networks. Seventy-six excavated samples of mineral, technical ceramic and slag from NPW and NKH were analysed in hand specimen, microstructurally by reflected-light microscopy and scanning electron microscopy and chemically by polarising energy-dispersive X-ray fluorescence spectrometry and scanning electron microscopy with energy-dispersive X-ray fluorescence spectrometry. The analytical data were used to generate detailed technological reconstructions of copper-smelting behaviour at the two sites, which were refined by a programme of field experimentation. Results indicate an approximately 1,000-year trend of Valley copper smelters' improving technical proficiency from what may be an experimental phase of production in the mid-first millennium BCE. This amelioration in production was accompanied by a substantial increase in the human effort of copper extraction. This shift in local ‘metallurgical ethos’ is interpreted as a response to rising regional demand for copper in late prehistory.     

RAMESSIDE GLASS-COLOURING CRUCIBLES*

The preparation of glass in New Kingdom Egypt heavily involved the use of crucibles. Shape, mode of operation and function of these vessels have been reconstructed on the basis of new, stratified material from the excavation at Qantir, eastern Nile Delta. The crucible fabric, the internal layer protecting the vessel from the charge, and the glass melted in the crucibles are characterized by chemical and petrographic studies. The crucibles were apparently employed mainly to add the colourants to the glass. The broader archaeological context strongly suggests that glass production in the Late Bronze Age has been a highly developed, specialized and organized craft, with different factories for glass production, for colouring, and for working, connected by a wide-ranging trade network.     

Lead isotope and metal source of Shang bronzes: a response to Sun et al.’s comments

In this brief response to Sun et al.’s ( 2018 ) comments on our paper, we re‐emphasize that archaeological, chemical and isotopic evidence are all relevant to the discussion about the metal source of the Shang period with highly radiogenic lead isotope ratios. The southern African bronzes have much lower lead contents and quite different lead isotopic signatures than the Shang bronzes. More importantly, there was no metallurgy of any kind in southern Africa before c.200 ce , so southern Africa cannot possibly be the source of Shang bronze, which date to about 1500 to 1000 bce .     

Metals,microanalysis and meaning: a study of metal objects excavated from the indigenous cemetery of El Chorro de Maíta,Cuba

This is the first publication reporting systematic analytical research conducted on archaeological metals from Cuba. The main focus of the study consists of beads and small metal objects excavated at the cemetery of El Chorro de Maíta, which comprises some of the richest funerary deposits so far recovered on the island. Some comparative samples from the nearby site of Alcalá were also investigated, with an emphasis made on the manufacture, composition and origins of the different alloys. The resulting picture is that members of the social elite of the indigenous Taíno peoples were buried with beads made of placer gold exploited locally, gold–copper–silver pendants brought from continental South America and, above all, brass lacetags from European clothing that were perceived as sacred metals. The archaeometallurgical approach offers fresh insight into the relationships between Europeans and Taínos, and the impact of colonization on the indigenous customs, values and social structures.     

An Interdisciplinary Study on the Environmental Reflection of Prehistoric Mining Activities at the Mitterberg Main Lode (Salzburg,Austria)

A multi‐proxy study by palynological, geochemical, archaeological and dendrochronological analyses discloses the mining activities at the Mitterberg Main Lode. By these means, several mining phases with varying intensity are recorded during the Bronze and Early Iron Age, whereupon a west to east shift of the mining activity at the Mitterberg Main Lode can be observed. The initial mining phase (Phase II), from the 21st to the 15th centuries bc , is characterized by an opening up of the forest vegetation and, additionally, by slightly elevated heavy metal deposition. Phase III shows a first bloom phase of the chalcopyrite mining during the 14th and 13th centuries bc . Pollen analyses disclose extensive clearings used for pasture and settlement. The increased human impact and higher heavy metal pollution suggest intensive mining activity, which is corroborated by the dendrochronological and archaeological data. Phase IV is characterized by mining activities in progress during the 12th century bc . The pollen data reflect a stabilization of the vegetation and slightly elevated As/Cu/Sb to Sc ratios. During Phase V, in the 11th century bc , new clearings indicate a re‐intensification of the mining activities at the Mitterberg Main Lode. Phase VI, from the ninth century bc onwards, describes a human impact with lower intensity at the mining site. This interdisciplinary study at the Mitterberg Main Lode contributes new environmental data for an important area of past metal mining and extends our understanding of the relationship between miners and their landscape.     

Isotopic and technological variation in prehistoric Southeast Asian primary copper production

The ‘Southeast Asian Lead Isotope Project’ (SEALIP) is intended to provide reliable geochemical proxies for late prehistoric through early historic (2nd/1st millennium BCE and 1st millennium CE) local, regional, and inter-regional social interactions, in an archaeological arena lacking established ceramic typologies with which to cross modern national boundaries. We present lead isotope characterisations of the three currently known Southeast Asian prehistoric primary (mining/smelting) copper production centres: Phu Lon and the Khao Wong Prachan Valley in Thailand, and the recently discovered Xepon complex in Laos. Kernel Density Estimation shows that these production centres can be clearly distinguished isotopically, as such fulfilling the core tenet of the ‘Provenance Hypothesis’ (Wilson and Pollard, 2001: 508) and permitting SEALIP to proceed as a research programme tracing regional copper/bronze/lead exchange and provenance patterning. In addition we provide a provisional technological reconstruction of copper smelting processes at Phu Lon to complement our more established understanding of the Khao Wong Prachan Valley. Combined lead isotope and technological datasets allow us to tentatively identify trends in the evolution of Southeast Asian metal technologies and of regional social perceptions of metal exchange.