How it began
Ancient miners worked copper deposits in Vilabouly District, Savannakhet Province, in central Laos, where the modern Sepon mine now operates. A 2019 study in the Journal of Archaeological Science dates the major mining and smelting sites of the Vilabouly Complex to the regional Iron Age, about 400 BCE to 500 CE, and possibly to the Bronze Age, about 1000 to 400 BCE. The remains of wooden shaft supports were found in 2009 during modern industrial mining.
How it works
The mine operator MMG reports that communities dug vertical shafts up to 40 meters deep and reinforced them with wooden bracing, a method it calls unusual. Radiocarbon dates from the wood, bamboo and rattan supports show mining over about 2,500 years. At Thengkham, vertical shafts were carbon dated to between 2,460 and 1,330 years ago. Analysis of 60 copper-base artifacts found copper, bronze and leaded bronze, with ingots, tools and ornaments made on site.
How it spread
Lead isotope analysis has been used across Southeast Asia over the past decade to trace copper to its source. The 2019 study reports that this work strongly suggests Laos played a central role in regional copper production and exchange networks for about 1,500 years, with regional demand for copper met in large part by Lao supply. Most of the artifacts tested matched the lead isotope signature of Vilabouly copper.
What lasted
The finds give a rare view of the history of metallurgy in mainland Southeast Asia, since metallurgical practice in Laos had previously been unknown. Objects recovered include a large bronze drum, long canoes buried ten meters below the surface, and a pot holding 4,000 glass, agate and carnelian beads with bronze bells. The study also suggests that halberds of Han Chinese type were produced on site.
Where it stands today
Since 2008 the mine operator has sponsored archaeological research at Vilabouly with the Lao Department of National Heritage and James Cook University. Lao officials, local villagers, volunteers and Australian students take part in the fieldwork. A cultural hall built in Vilabouly holds artifacts, and other pieces are displayed in Savannakhet and at the Lao National Museum in Vientiane. Modern copper mining continues in the same district.
