A study of a lead isotope ratio and a Fe chemical state of lead glaze earthenware : characteristic for a firing technique and a provenance

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K01190
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Cultural assets study and museology
• Research Institution: Kyoto National Museum (2017-2019); Nara National Research Institute for Cultural Properties (2016)
• Principal Investigator: Furihata Junko 独立行政法人国立文化財機構京都国立博物館, 学芸部保存科学室, 室長 (60372182)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 奈良三彩 / 胎土分析 / 非破壊分析 / 鉄価数 / 軟質陶器 / 鉛同位体比 / 鉛釉陶器 / 須恵器

Outline of Final Research Achievements

This study focuses on firing technology used to make the type of white, soft, low-fired ceramics identified in early examples of the eighth-century Japanese three-color lead-glazed earthenware known as Nara sansai. In order to investigate characteristics of the firing of this iron-rich ware and to develop a technological genealogy, this study measured the iron valence and iron content of the clay. Based on nondestructive analysis, it was determined that post-excavation analysis of such objects is affected by iron content from the surrounding soil and groundwater, which has permeated into the porous soft bodies during burial. In the experimental sample, this was determined to have reached a depth of about 3 mm. It also points out that firing temperatures can be estimated from XANES spectra measured with the Fe-K edge fluorescence method.

Free Research Field

文化財科学

Academic Significance and Societal Importance of the Research Achievements

本研究では、原材料や生産技術の特徴を示すことで、古代の鉛釉陶器の生産体制について新たな視点から検証するという特徴をもつ。原材料の画一性の有無について、その要因を明らかにすることで、原材料の時代による変遷、地域性などを明らかにし、また焼成技術という生産技術の変遷からその技術的系譜の究明に有用な情報を取得する。これらの調査は、様々な文化財資料へ幅広く適応されることに意義があるため、非破壊による分析調査は非常に重要である。本研究では非破壊調査法によって得られたデータから、生産技術に関する情報のみならず、新たに注意すべき知見が得られたことに意義があると考える。