A prehistoric industrial site discovered in Gansu Province, China, has pushed back the timeline for advanced tin-bronze alloying in the region. The site includes multiple high-temperature kilns and molds for casting complex tools, dating to the late Neolithic period.
Chemical analysis of the slag indicates a highly standardized recipe for bronze, suggesting that these early metalworkers possessed a sophisticated understanding of mineral properties. This site predates the major Erlitou bronze centers by nearly a millennium, forcing a revision of early East Asian history.