• Economic and Environmental Geology
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• v.57 no.5
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• pp.647-664
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• 2024

Material and archaeometric characteristics of the original and repaired bricks and roof tiles of the Bogd Khaan Palace and the Choijin Lama Temple, which represent modern Mongolian architecture, were analyzed. These bricks and roof tiles are light gray, and the repaired ones mostly had higher specific gravity and porosity than the original ones. In the body clay, coarse grained sub-angular quartz, alkali feldspar, plagioclase and mica are commonly observed, and hornblende was partially detected. Compared to the original bricks and roof tiles, the repaired ones have a homogeneous substrate and significantly less tempers, suggesting that refined techniques were applied. Weight loss of these bricks and roof tiles was lower in the repaired ones than the original ones, and although there were thermal deformation and non recrystallized. Also, Al₂O₃ was high in the original bricks and roof tiles, and CaO was high in the repaired ones, and Na₂O and ignition loss were low. However, since the other elements showed almost the same behavioral characteristics, it is interpreted that they used homogeneous body clay regardless of location and time. Therefore, the clay content of the raw materials for the original bricks and roof tiles were higher than that used for the repair, but it is highly likely that they were procured from almost the same soil as the body clay, and the firing environment does not seem to have affected the geochemical behavior of the body clay. But, the high Al₂O₃ and CaO in the repaired bricks and roof tiles indicates the possibility of partial refinement and mixing of the clay. There were no high-temperature minerals in all the bricks and roof tiles, and based on the detection of mica and hornblende, the absence of clay minerals and the thermal deformations of the substrate, their firing temperature is presumed to be 850 to 900℃. This was almost the same in the bricks and roof tiles used for the repairs. This result is significant as material science data for the bricks and roof tiles used in modern Mongolian architecture, and will be useful grounds for examining the making techniques of bricks and roof tiles for future restorations.