Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Mitsui, Seiichiro; Murakami, Ryu*; Ueda, Norio*; Hirabayashi, Akira*; Hirota, Kazuho*
Bunkazai Kagaku, (77), p.1 - 14, 2018/10
Well-preserved bronze artifacts comprising five bells and eight halberds from the Yayoi Period were excavated at the Yanagisawa archaeological site in Nakano City, Nagano Prefecture in 2007. Comprehensive analysis of soil and groundwater samples at the site was carried out and geochemical calculations were made to better understand the local conditions that led to the artifacts being so well preserved. Analysis of the soil surface adjacent to the bronze artifacts identified cuprite (CuO) as the main corrosion product. Migration behavior of the bronze metal components, copper, tin, and lead, both inside and outside of the burial pit, was also investigated. Copper and lead had migrated 2 m from the burial pit, whereas tin was confined to the immediate vicinity of the bronze artifacts. The difference in migration behavior of these elements can be explained in terms of the chemical stability of the solid phases. The main factor contributing to the well-preserved state of the bronze artifacts was the tin content, which is thought to have formed a protective layer of cassiterite (SnO) on the outer surface of the bronze artifacts.
Murakami, Ryu*; Mitsui, Seiichiro; Hirabayashi, Akira*; Ueda, Norio*
Nihon Bunkazai Kagakkai Dai-26-Kai Taikai Kenkyu Happyo Yoshishu, p.108 - 109, 2009/07
Bronze halberds and bells in the Yayoi Period have been excavated from Yanagisawa archaeological site in Nakano City, Nagano Prefecture. This is the first case which both the artifacts were coincidentally excavated in eastern Japan and is important archaeological discovery. To identify the reason of good preservation of the artifacts, we analyzed soil and groundwater at the site as burial conditions. We also investigated migration behavior of copper, lead and tin as metal components derived from the artifacts in the surrounding soil. The results indicate that the preservation of the artifacts depends on the burial environment. In addition, we found that copper and lead migrated to the position of two meters from the pit buried the artifacts.
Mitsui, Seiichiro; Murakami, Ryu*; Hirota, Kazuho*; Ueda, Norio*
no journal, ,
Bronze halberds and bells in the Yayoi Period have been excavated from Yanagisawa archaeological site in Nakano City, Nagano Prefecture. To identify the reason of good preservation of the artifacts, we analyzed soil and groundwater at the site as burial conditions. We also investigated migration behavior of copper, lead and tin as metal components derived from the artifacts in the surrounding soil. The results indicate that the preservation of the artifacts depends on the burial environment. In addition, we found that copper and lead migrated to the position of two meters from the pit buried the artifacts. On the other hand, tin distribution is confined to the immediate vicinity of the artifacts.