片桐 成夫 島根大学, 農学部, 教授 (00032649)
ITO Haruaki Shimane University, Faculty of Science, Professor, 理学部, 教授 (80032423)
TOKUOKA Takao Shimane University, Faculty of Science, Professor, 理学部, 教授 (30025358)
HASHITANI Hiroshi Shimane University, Faculty of Science, Professor, 理学部, 教授 (00156267)
INOUE Hiroshi Shimane University, Faculty of Law and Literature, Professor, 法文学部, 教授 (40027967)
ONISHI Ikuo Shimane University, Faculty of Science, Professor, 理学部, 教授 (40032445)
|Budget Amount *help
¥12,700,000 (Direct Cost : ¥12,700,000)
Fiscal Year 1991 : ¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1990 : ¥11,000,000 (Direct Cost : ¥11,000,000)
As for the ancient metal production (copper and iron) in the San'in districts, the following questions have been discussed and attracted much attention of citizens as well as scholars, i. e. ., the question as to where a large quantity of Yayoi bronze ware unearthed from the ruins of Kojindani in Hikawa-cho was produced, and the question concerning the possibility of iron production from iron sand from early periods in the San'in districts centering around ancient Izumo. It is expected that the solution of these questions might make clear the greatest mystery in the ancient history of Izumo and its peripheral regions rich in mythology and oral tradition, that is, the aspects and characteristics of local political power in ancient times.
The results of the research concerning the first question can he summarized in two points : , 1) A matter of primary concern is whether bronze ware was really produced in the San'in 'districts, especially around the ruins of Kojindani. In this regard it
could not be proved that it occurred in the Izumo districts in the Yayoi period ; however, the inference was made that bronze ware was produced at least around the 7th to 8th centuries. 2) The research confirmed that copper ore, which makes possible an on-the-spot production, is rich in the San'in districts, in particular in the Shimane Peninsula, where it occurs in a purer form as native copper.
The results of the research regarding the second question. are the following : 1) The beginning of iron production in the San'in districts occurs in the latter half of the 6th century. However, it is unthinkable that it spread widely at this stage, and it seems to be after the 7th century that it, came into wide use. 2) The raw material of such iron production in the early stages was iron sand. 3) The furnace in which iron sand was dissolved is box-shaped. 4) This sort of iron production seems to have been popular around the base of Mt. Daisen in Tottori Prefecture, along the coasts of Nakaumi Lagoon and Lake Shinji, in the Oku Izumo districts, and around the middle courses of the GSno River. 5) It is after the 7th century that, the process of iron production from the early stages to the production of tools is roughly completed, and in earlier periods the raw material of iron seems to have been brought from other places and was refined to make cutlery and armory. Among the ruins of Iwayoshi in Tottori Prefecture, objects of refining and smithery from the 5th century were found. The research of ancient metal production in the San'in districts is gradually accelerating.