Archaeological interpretations on the Slender Bronze Dagger Culture Period have been reconsidered within the academic communities of Korea and Japan on the basis of C14 (AMS) dates. The purpose of this paper is to examine this current trend. It is acknowledged that chronological dating based on typology is weaker than scientifically based C14 dating. However, C14 dates are also not without problems. In addition, there is a class of archaeological evidence that can provide dates that may be regarded as being more secure than C14 dates, namely Han bronze mirrors, the manufacturing and use dates of which are known. The mirror excavated from Pyeongjang-ri is an example of this.
The bronze artifacts excavated from Pyeongjang-ri are very useful in calculating the absolute dates of the Korean Peninsula, as well as in cross-dating data when the Slender Bronze Dagger Culture spread to the Yayoi society of Japan. The date of the mirror decorated with four leaves and four dragons from Pyeongjang-ri corresponds to the first quarter of the 2nd century BC, around the beginning of the West Han Dynasty. The findings of this paper, in which the date of the mirror from Pyeongjang-ri has been applied to the chronological study of the Slender Bronze Dagger Culture Period is as follows.
① The beginning of the Slender Bronze Dagger Culture Period in the Korean Peninsula can be dated to the first half of the 3rd century BC. ② The Gubong-ri phase, in which the Slender Bronze Dagger Culture was completed, dates to the end of the 3rd century BC, which corresponds to the unified Jin Dynasty. ③ Elements of the Early Iron Culture appeared in the southwestern part of the Korean Peninsula at the beginning of the 2nd century BC, corresponding to early West Han. ④ The pottery with an attached-rim triangular in cross-section appeared in the middle of the 2nd century BC. ⑤ The Slender Bronze Dagger Culture and the Early Iron Culture spread to Japan around the same time, during the first half of the 2nd century BC, which corresponds to the end of the early Yayoi to the beginning of the middle Yayoi period. ⑥ The early Yayoi period began from the mid-3rd century BC.