考古学と火山灰層序

特に関東地方を中心とした旧石器時代の層位的出土例と石器群の様相

抄録

Study of the paleolithic culture based on the stratigraphy had begun with an excavation of the Iwajuku site, Gunma Prefecture, and advanced after 1968, when so-called “After Tsukimino-Nogawa” cultural stratigraphy was established. More than 10 cultural layers are found from the Tachikawa Loam which is 3 to 7m thick and devided into 6 or 8 strata by tephras. Four main industries can be distinguished in the cultural layers; (1) industry mainly composed of becs industry, (2) knife-like backed blade industry, (3) microblade industry and industry mainly composed of points.
Paleolithic materials in the Kanto district were examined on the following 7 items; (1) scale of the site based on the number of artifacts, (2) concentration of artifacts, (3) distribution of fired pebble heaps, (4) stone tool assemblages, (5) lithic composition, (6) types of knife-like backed blade and (7) blade technique and its blanks. These analyses enabled to make a correspondence between cultural layers among sites in upper Nogawa River on the Musashino upland, and analysed sites were classified into 3 types; (a) the site with a single cultural layer, (b) the site composed of continuous cultural layers, (c) the site composed of several discontinuous cultural layers. The continuous cultural layers had a tendency to produce bigger amount of artifacts than the discontinuous cultural layers. Changes in the lithic feature of discontinuous cultural layers seem to be rapid, suggesting an intermittent occupation of the site. This phenomenon can be recognized not only successive cultural layers in a site, but also cultural layers of the same strata among different sites. Comparison between the cultural layers below the AT (Aira-Tn ash) and those above the AT showed that lithic features changed remarkably at the AT boundary. It is interesting that changes of the lithic tradition had a close correlation with the environmental change.