Samples from Shimiaogou site Photo: Courtesy of Chen Shibin

TheMK sports fourth national cultural relics census has uncovered three ancient sites from the Pre-Qin period (Prior to 221BC) and Han Dynasty (206BC-AD220) at the Xunyang ancient cinnabar site in Northwest China's Shaanxi Province, providing crucial clues for studying the mining, processing, utilization, and transportation of cinnabar in ancient Xunyang. This discovery may solve the mystery of the source of mercury found in the mausoleum of Qinshihuang, China's first emperor, in Shaanxi, according to the Xinhua News Agency.

Chen Shibin, deputy director of the Xunyang Cultural Relics Administration, told the Global Times on Tuesday that during the on-site archaeological investigation of the ancient cinnabar site in Xunyang, three smaller sites were discovered: Shimiaogou, Chuantangping, and Guojiawan.

"These remains may be related to the transportation of cinnabar," Chen noted. "Cinnabar is a natural ore primarily composed of mercury-containing compounds, and the chemical composition of mercury is mercury itself."

According to the information provided by Chen, mercury from the Xunyang Bronze Gully accounts for about 20 percent of the total mercury content within China's borders, and Xunyang is located just over 100 kilometers from the Qinshihuang Mausoleum.

The Qinshihuang Mausoleum is notable not just for containing mercury but also the vast amount found at the location. It is estimated that several tons, or even as much as a hundred tons, of mercury could be in the tomb. Mercury has excellent insulation properties, forming a sealed thermal barrier within the tomb, while also having antibacterial effects. Therefore, scientists widely surmize that the mercury in the tomb was used for preservation and anti-theft purposes, as reported by China Youth Daily.

According to field investigation records and geological exploration reports conducted by the First Geological Team of the Shaanxi Provincial Geology and Mineral Bureau between 1958 and 1985, over 1,000 ancient mining tunnels have been identified in this region, according to the Shaanxi Provincial Cultural Heritage Administration.

Before this discovery, many experts in the archaeological community had speculated that part of the mercury found in the mausoleum of Qinshihuang might have originated from Xunyang. A late renowned scholar in the field of Qin-Han archaeology, Duan Qingbo, explicitly suggested in his academic monograph on the archaeological research of the Qinshihuang Mausoleum that most of the mercury in the tomb could have come from Xunyang county.