공주 교촌리 3호 전실묘 벽돌의 태토산지와 제작기술

Abstract

Gyochon-ri brick tomb No.3 was excavated as the third brick tomb during Ungjin period, Baekje, following Songsan-ri No.6 and the royal tomb of King Muryeong. In this study, scientific analysis on the bricks from Gyochon-ri brick tomb No.3 was carried out to interpret their manufacturing process and relationship of distribution. The bricks of Gyochon-ri brick tomb No.3 are all with no pattern, and divided into three types in shape: a square brick (cross-sectionally trapezoidal) and rectangular bricks (crosssectionally trapezoidal or rectangular). They are composed of quartz, alkali-feldspar and mica and estimated to have been fired at the firing temperature of 700 to 900℃ in oxidation reaction firing which gives reddish brown color. Bricks have elongated pores caused by carbonized plants in fine raw clay material, and more refined soil was used for square bricks than rectangular bricks. Through the prior study, it was estimated that the bricks of the royal tomb of King Muryeong and Songsan-ri brick tomb No. 6 were manufactured in Jeongdong-ri, Buyeo, showing the same geochemical characteristics of bricks from Jeongdong-ri kiln site. However, bricks from Gyochon-ri brick tomb No. 3 showed different geochemical distribution from other bricks, which means that selection of raw clay materials and the manufacturing process of bricks were presumed to have been different from others. However, they showed the same pattern and material characteristics with other Songsan-ri bricks collected during the Japanese colonial period, indicating the possibility that those bricks from Songsan-ri might have been partially acquired from the collapsed Gyochon-ri brick tomb and stored in Gongju National Museum since then. When compared with most of bricks from the royal tomb of King Muryeong and Songsan-ri No. 6 which were fired from 1,000 to 1,200℃ under reduction condition and have densely structured textures, bricks of Gyochon-ri brick tomb No. 3 are considered to be manufactured at a technical difference in terms of their pattern, shape, texture of raw clay material and firing temperature. In addition, while lime was used for brick joints and reinforcing material based on the construction technique of the royal tomb of King Muryeong and Songsan-ri No. 6, lime was not used for brick joints of Gyochon-ri brick tomb No.3. In place of lime, clay-rich soil in a very fine-grained size was used for joints, which is thought to have been weak in durability and difficult to support the weight of its ceiling for a long time.