In Imdang-dong site in Gyeongsan, Gyeongbuk Province, 346 wooden artifacts were excavated and they are considered as one of very important relics to show the state of living in our ancient times with other wooden artifacts from Shinchang-dong site in Gwangju, Daho-ri site in Changwon, and Sungsan mountain fortress wall in Haman. This study aimed to identify the woodworking methods of these wooden artifacts through the species identification, the manufactured trace in the wooden artifacts and the lacquerware analysis, and to estimate the paleoenvironmental conditions based on results from dendrochronological analysis and the species identification.
Among the wooden artifacts, the 317 artifacts, e.g. container artifacts, farm and machine tools, and living tools, were identified for tree species. Identified trees were included into one softwoods and twenty-three hardwoods. Lepidobalanus and Platycarya strobilacea S. et Z. and Pinus spp. which occupy 24.6%, 18%, 17.4% of total wooden artifacts, respectively. As for the wooden container artifacts, they were identified to be made of Platycarya strobilacea S. et Z. and Hovenia dulcis Thunb., which were not commonly used in other sites and it represents a regional characteristic. As for the farm and machine tools, they were identified to be made of Lepidobalanus, which is known for its high strength, and as for the living tools, the analysis result was the same with that of other relics, except only for the wide-tooth comb, which was made of Betula schmidtii Regel.
Through the way of tool trace and processing method, which is a way of examining the surface of wooden artifacts, the tools and methods used for manufacturing artifacts were analyzed. From the tool traces on the surface of the 97 wooden artifacts, it was found that the carpenters have made use of various artisan tools like an adze, a chisel, an awl, a hand-knife, and an axe. Surprisingly, there were traces of a turning lathe and a turning knife and it showed the turning methods had already existed. Also, it was found that wooden container artifacts had been crafted by applying both Nunjil (Tangential process) and Seonjil (Longitudinal process) methods in order to make use of wooden materials suitable for its shape and usage effectively.
In order to identify the lacquerware technique at that time, the analysis of lacquerware was conducted on the 88 lacquer artifacts and, then, the optical/polarization microscopy and SEM-EDX were used. On the lower layer, filling materials such as powdered soil, soot and charcoal were painted, and for the red pigments, the iron oxide (Fe2O3) was used. The 5 techniques were identified on the lower layers, and according to the kinds of colors of mixed pigments on the middle and surface layers, they were divided into 17 techniques. Compared with techniques of other ancient sites in the same age (2-5C), the techniques of Imdang-dong lacquerware artifacts are the same as other sites'' techniques for painting the lower layers, but as for the red pigments, the iron oxide (Fe2O3) was usually used in Gyeongsang province.
The age of Imdang-dong site (2-5C) in Gyeongsan was dated by examining the artifacts and the soil lawyer which relics were excavated from. However, in order to identify the exact date, the six wooden pillars, which were excavated there, were analyzed through the way of dendrochronological dating. The result of tree-ring dating showed that the each chronology of six wooden pillars was not matched with each other, so, they were identified to have been cut in different times. 2 of 6 wooden pillars, however, were dated A.D. 94-135 and A.D. 224-289, respectively, through the way of radiocarbon dating (wiggle matching), therefore, the estimated date could be reconfirmed.
Based on the results of dating for the wooden pillar (Prinus group) and of species identification for wooden artifacts, the paleoenvironmental condition in Imdang-dong site was estimated. As the narrow ring-width patterns in wooden pillar coincides with the records of drought in history (Samguk Sagi, a historic record of three kingdoms), it has been proved that the tree-rings contain such climate information.
In addition, in order to get a glimpse into the climate then, the vessel lumen of the still living Quercus mongolica Fisch (Prinus group) close to the Imdang-dong site were compared with them of the wooden pillar, and it was found that the climate of Imdang-dong site was more moisture at that time than the current time. Moreover, as in the results of species identification, some species (Hovenia dulcis Thunb., Tilia spp., Ulmus spp.), which grow naturally in a little cool environment, were found. It also indicates the environmental condition at that time was cooler than now, and this finding is consistent with other research publications.