The diffusion process of dolmens in Southern Korea and Northern Kyushu

Abstract

This paper aims to specify the region of origin and to investigate the diffusion process of the rice agriculture-based cultural complex introduced from the southern region of the Korean peninsula to Japan in the Initial and Early Yayoi Periods by analyzing the dolmens in Southern Korea and Northern Kyushu.
Dolmens have been investigated as an important trait of the rice agriculture-based cultural complex. However, the region of origin and the route of diffusion remain the subject of dispute. Although the region of origin is widely accepted to be somewhere in South Cholla province of Southwestern Korea, whether the route passed through Cheju island or the Tsushima / Iki islands has not been determined. Whether the North-western Kyushu region or the Genkai-nada coastal region first accepted them has not been determined, either. Neither has the cause of regional differences in the mortuary facility, i.e., pits or wooden coffins in the Genkai-nada coastal region, stone coffins in north-western Kyushu, burial pits with stone-slab covers in the Saga plain, been fully examined: whether they derived from different prototypes or they resulted from differing processes of modification through the diffusion is the point of contention. A serious problem shared by all the theses is that only a tiny number of the dolmens of southern Korea were excavated scientifically in the 1960's and 1970's when the theses were proposed.
In order to identify the proto-type of the dolmens of Northern Kyushu, the author reclassified the dolmens of Southern Korea in comparison with the earliest specimens in Northern Kyushu. Then the author examined affinity between the Southern Korean prototypes and Northern Kyushu specimens in terms of how many traits were shared between them. Based upon the outcome, the author constructed a model of the diffusion route from Southern Korea to Northern Kyushu. The validity of the model was examined by a statistical method, the quantification theory typeIII.
The author reached the following conclusions. First, the prototype of the dolmens of Japan had a wooden coffin protected by a stone compartment as the burial feature. Second, the dolmens of Japan originated in the Nam-gung River basin of Southern Korea. Third, the probability that dolmens diffused to Japan through Cheju island is low. Fourth, dolmens were firstly introduced to the Genkai-nada coastal region and then diffused to the surrounding regions.