- 公益社団法人 東京地学協会
- 地学雑誌 (ISSN:0022135X)
- vol.117, no.5, pp.948-952, 2008-10-25 (Released:2010-04-27)
The present study represents an attempt to determine the sources of vermilion found in ancient Japanese burial mounds prior to the emergence of the ancient Yamato dynasty. For this purpose, cinnabar ores were collected from Chinese and Japanese mines, and samples of vermilion were also collected from ancient tombs. When the vermilion collected from the tombs was studied morphologically, different particle sizes were observed. However, the particle size of the artificial vermilion was found almost same. The metal contents of cinnabar ores were different for each Japanese mine: Niu (Mie Pref.), Yamato Mercury (Nara Pref.), Sui (Tokushima Pref.), and Itomuka (Hokkaido Pref.) mines. Arsenic (As) content was highest in cinnabar ore from Niu mine; Mn and Fe contents were highest in Yamato Mercury mine; and, the Ba, Ca, Co, Cr, and Sr contents were highest in Sui mine. When analyzing the metal contents of vermilion collected from ancient tombs in Nara Prefecture, vermilion collected from Kurozuka, Kamotsuba, and Tomio-Maruyama tombs showed a high As content, and vermilion from Tenjinyama tomb showed a high Mn content. Thus, the possibility was suggested of identifying the original vermilion mine from the metal contents. However, it is difficult to set borderlines for the metal contents of vermilion to identify the source mine. So, the ratios of sulfur isotope (δ34S) in ores and vermilion were compared. A high δ34S value of +22.6 ± 3.6‰ was found for the ore of Wanshan of Guizhou and from +6 to +10.6‰ for Xunyang of Shaanxi in China, as opposed to low values ranging from -7.3 ± 1.9 to -2.1 ± 1.6‰ for Japanese mines. It is thought that δ34S values are suitable for determining the sources of vermilion found in ancient tombs. In addition, high ratios from +7.4 to +22.8‰ were found in 1st- and 2nd-century burial sites in northern Kyushu and San'in, and lower ratios from -8.4 to -2.0‰ were found in burial sites of the 2nd through 6th centuries in central Japan. Therefore, powerful local chiefs living in northern Kyushu and San'in areas might have obtained vermilion through relations with China, but chiefs living in central Japan might have used vermilion collected from Japanese mines. In conclusion, the sources of vermilion collected in ancient tombs can be determined by measuring δ34S values. An additional analysis of a lead isotope ratio, for example, might also be necessary to determine the source of vermilion.