Petrographic and chemical analyses of ceramic roof tile end caps from the ritual temple of Jin Dynasty in Changbai Mountain

The site of Baomacheng has revealed the largest known imperial ritual temple dedicated to a mountain god in China. Constructed by Emperor Shizong of the Jin dynasty between the 12th and 14th years of Dading (1172 CE-1174 CE), the site yielded abundant roof tile end caps, categorized into six typological groups. 88 samples were analysed for their major and minor element composition, and 38 of them were also subjected to trace element composition analysis. The geochemical patterns suggest that the raw clay used for these end caps significantly differs from local basalts but closely resembles the trachyte found around the Tianchi volcanic cone, indicating that they were the weathering product of this type of rock. Petrographic analysis divided the samples into five fabric groups: two rich in residual orthoclase feldspars and three characterized by a fine matrix and large ferromanganese nodules. The stylistic types of tile end caps correspond well with these fabric groups, suggesting that a series of workshops were employed simultaneously during the construction of this magnificent temple. This multi-supplier model has been recognized as a significant feature in the imperial construction works of historical China.