Earticle

This study was carried out to identify the species of wooden coffins excavated from ancient kings' tombs of Nakrang and Pro-Three-Kingdoms to the beginning period of the Three Kingdoms, and the private tombs of the middle stage at the Yi dynasty. The species of wooden coffins were identified as three softwoods(Thxus cuspidata, Sciodopitys verticillata, Pinus densiflora) and six hardswoods(Quercus acutissima, Quercus serrata, Zelkova serrata, Platycarya strobilarea, Alnus japonica and Morns spp.). Thxus cuspidata, wooden coffins of Nakrang kings' tombs, is distributed through Korea. However in previous examination it was known as Cunninghania lanceolata, native species in south China. Sciodopitys verticillata used as a wooden coffin of King Muryung's tomb was native to Japan. It was a material evidence proving the cultural exchange between Paekche Kingdoms and Japan in those days. Pinus densiflora was the species of wooden coffins excavated from private tombs in Yi dynasty, which was not found out from Pro-Three-Kingdoms and Three-Kingdoms. Quercus accutissima was used for making a trough shape wooden coffins at Daho-ri ancient tombs and Quercus serrata was used a outer wooden coffin of Nakrang kings' tombs. An adamant iron mongery might be used to manufacturing a trough shape wooden coffin. This indicates that a developed iron-manufacturing technics existed in Korea at that time. Zelkova serrata was used for making wooden coffins of Imdang and Kaya ancient tombs, Chunma and Hwangnam king tombs. Platycarya strobizacea was used for making wooden coffin of Daegok-ri, Alnus japonica for Daho-ri coffins and Morus spp. for Imdang coffins.

To understand the morphological change of ancient woods, samples classified by cell type, burial environment and species were collected and observed using microscopy. Decay of wood by cell type could classified into two types. First, degraded secondary wall was formed granular residues in layer and was remained layer and compound middle lamella. Second, the cell wall was slightly degraded and cracked in secondary wall. A gradual thinning of cell wall was occured. The compound middle lamella was separated from secondary wall. The resistance of degradation is increased at vessels, parenchyma, and tracheid and wood fiber in the order named. The type of degradation by species could be classified into four types. Overall degradation type; the degradation of cell wall is usually heavy and the extent of degradation Varies by part of the same sample. Partial degradation type ; this type shows severely different decay type by part of the sample. Nondegraded cells were mixed with degraded cells on the same sample. Erose degradation type ; thinning of the cell wall was occoured and the degradation type was different by part. Slight degradation types ; secondary wall was slightly degraded, cracked and separated from compound middle lamella. Considering different type of burial environment, dry wood was similiar to sound wood and slightly decayed. Waterlogged and peat burial wood was heavilydecayed. Between species of under the same environment, decay type and extent were diferentiated from each other.

Materials (refractory, stone) of iron making furnace excavated from Kalcheon were investigated by the scanning electron microscopy(SEM) with an energy dispersive X-ray analysis (EDAX), X-ray fluorescence(XRF), and X-ray diffraction(XRD). Chemical composition of the refractory materials were in weight ratio, which were the typical components presented in common clay. The results of chemical analysis for the stone and the glaze coated, alkali ion(K, Na, Ca) components of the glaze contained high concentration than that the stone. It was suggested that this change had a close relationship with the kinds of fuels used.

Stone -monuments, distributed in this area, have been investigated and studied in geological and conservational points of view. They are seemed to have been mainly built from the Shilla to Koryeo Kingdom, although more systematic studies are needed. The used rocks in these monuments are mainly biotite granite and hornblende-biotite granite of Jurassic age. The rock phases are nearly identical to those which are distributed in the area. The two rock phases are nearly same in the characteristics of minevalogy and texture except the amount of hornblende. However, hornblende-biotite granite characteristically contains aggregates of mafic minerals which are frequently observable in the monuments. They are mainly influenced by chemical weathering due to warm, abundant rainfall, and salty moisture because of being adjacent to the sea. Some cracks are secondarily developed which may be due to strong chemical weathering and influence of sculpturing. For conservation, it must be scientifically considered based on characteristics and kind of rock phase, factors on weathering process, situation and protection.