The archaeometallurgy of Dragon Field and Peun Baolo, Savannakhet Province, Laos: Stage one results and recommendations

Cawte, Hayden (2009) The archaeometallurgy of Dragon Field and Peun Baolo, Savannakhet Province, Laos: Stage one results and recommendations. Report. UNSPECIFIED. (Unpublished)

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Abstract

A major turning point, the introduction of metalworking into prehistoric society saw the development complex political economies. There is, however, a particular nescience with regard to the metallurgy of Southeast Asia and the impact that its introduction had in this region. This is particularly true of the Lao PDR, for which there are no known archaeometallurgical sites. Metallurgical investigation in Southeast Asia has largely focused on Thailand for which we now have a rich panoply of data. Consequentially much of what we know about bronze metallurgy, its operation, spread and development in Southeast Asia comes solely from Thailand. Discoveries of metallurgical sites outside Thailand are therefore of considerable significance.

Contemporary copper and gold mining by Lang Xiang minerals in Savannakhet Province, Southern Laos, has unearthed what are thought to be two prehistoric archaeological sites Puen Baolo (PBL) and Dragon Field (DF). Their proximity to areas of known copper mineralisation are unlikely to be a coincidence and archaeological excavations conducted at each of these sites by Dr. Chang of James Cook University have uncovered material thought to be metallurgical in nature.

The aim of this report, conducted under the aegis of Dr. Chang and Lang Xiang Minerals, is to determine whether we now have the first metallurgical material from a prehistoric site in Laos and if so, the nature that this material takes. Confirming this material as metallurgical, and identifying the nature of their operation, would allow Laos to take a central stage in regional archaeology as well as providing a much needed new perspective on Southeast Asian archaeometallurgy and the debates surrounding the introduction and impact of bronze.

Using mainly optical and Scanning Electron Microscopy (SEM), analysis has confirmed the material relates to a copper metallurgical industry with crucibles being the most abundant ‘technofact.’ Other materials include, slag, ore/gangue, and a leaded-copper ingot from Dragon Field.

Most importantly, these crucibles have been identified as being involved in the primary production of copper from its ores, by crucible smelting. This is usually restricted to easily smelted copper oxide ores, however, evidence suggests that the more difficult sulphide ores were also being smelted. Evidence from PBL suggests that its inhabitants were co-smelitng oxide and sulphide ores in a sophisticated, somewhat mechanical manner. Crucibles here were used as “reaction vessels” (cf. Bennett, 1989) whereby oxidic and sulphidic ores were combined and the oxygen and sulphur in each ore ‘reacted’ producing the gas SO2, removing both from the system, leaving slag and most importantly, metallic copper. At DF, however, we can be less certain of operation without further information. It is possible that its inhabitants were reduction smelting oxidic ores (smelting in the absence of oxygen using charcoal as reducing agent) (suggesting DF maybe older than PBL) or smelting sulphidic ores that had been processed to remove all sulphur (dead-roasting) prior to reduction smelting (suggesting DF later than PBL). Further research will provide more answers here.

This report represents a significant advancement in our knowledge of how prehistoric metallurgy was conducted in Southeast Asia. Given these findings, Laos can now take its place as a regional player in the spread and development of metallurgy throughout this colourful region.

Although this report has provided much information, further investigation is required, especially from Dragon Field in order to fully understand the industry including the relationships between DF and PBL and between PBL, DF and their surrounding landscapes, as well as identifying the important relationship between people and technology. The key point is whether the inhabitants of these sites were also mining the copper from the hills around them or were they merely smelting pre-mined material? Therefore the following recommendations ensue;

*Conduct a comprehensive archaeological survey of the surrounding areas of both Puen Baolo and Dragon Field. Especially for evidence of surface mineralisation, mining, beneficiation, slag deposits as well as for landscape modifications.

*Further excavate Puen Baolo but especially Dragon Field to retrieve further material for analysis.

*Conduct further analysis on retrieved material.

*Investigate the DF ingot by sectioning it for analysis under scanning electron microscope.

*Analyse portions of the possible ore/gangue retrieved from these sites.

*Of importance is the need to date these sites, therefore the final recommendation is to identify material that will provide radiometric dates for occupation.

Item ID: 10770
Item Type: Report (Report)
Date Deposited: 02 Jun 2010 01:46
FoR Codes: 21 HISTORY AND ARCHAEOLOGY > 2101 Archaeology > 210103 Archaeology of Asia, Africa and the Americas @ 100%
SEO Codes: 97 EXPANDING KNOWLEDGE > 970121 Expanding Knowledge in History and Archaeology @ 100%
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