Stratigraphy at Naka-ikemi consist of a lower sand and gravel layer and an upper humus layer which includes widespread tephras, Ata, K-Tz, Aira-Tn (AT), and K-Ah. By comparing pollen spectra of the upper humus layer below AT for five drilling cores, vegetation changes at around Naka-ikemi during the late Pleistocene are reconstructed. Overall dominance of Cryptomeria pollen below AT indicated that Cryptomeria japonica forests spread widely through the periods. Differences in pollen assemblages between drilling points showed that deciduous oak forests distributed on the northern hills, alder forests grew in the wetland, and Cryptomeria japonica forests extended along the southern valley. At about 80,000 years ago, Castanea/Castanopsis pollen increased, with an enlargement of depositional area to the south, and was taken over by an increase of deciduous broadleaf tree pollen, followed by an extention of depositional area to the north. At around 50,000 years ago, marked by a brief increase of Hydrangea type pollen, Alnus and Lysichiton pollen increased, Sciadopitys pollen decreased, and Cupressaceae type pollen increased. Simultaneously, the depositional environment of Naka-ikemi changed from lake to moor. An increase of Tsuga, Pinus, and Betula pollen just below AT showed the onset of a cold phase leading to the last glacial maximum.
This paper discusses cultural implication of tub-shaped and box-shaped wooden coffins from the Hatchobori 3-chome Site (early half of the 17th century), Chuo-ku, Tokyo. The site is a typical commoners’ graveyard of the age, and the research focus was set on social hierarchy represented by the burial style. Altogether 1418 pieces of wooden artifacts from the site were identified wood anatomically. In addition, grain and thickness of the coffin boards were studied. Tub-shaped wooden coffins and tubs for cremated bones were mainly made of Chamaecyparis pisifera, whereas box-shaped coffins were made of Cryptomeria japonica, Chamaecyparis obtusa, and Chamaecyparis pisifera. The diversity of taxa suggests that those box-shaped coffins were made of used timbers. This shows clear difference from typical coffins for Shogun and Daimyo families, probably representing their social distinction. Moreover, boards of tub-shaped coffins tended to be thinner in the later age of the site, especially in those of Chamaecyparis obtusa and Chamaecyparis pisifera. According to pollen and historical records, Chamaecyparis pisifera probably grew in the Kiso and Tenryu valleys, and the studied coffins were considered to have been mass-produced using timbers imported from those areas. On this basis, it is assumed that eventual scarcity of trees caused by increasing demands for timbers in the city areas resulted in coffins made of thinner boards of diversified species. Absence of social hierarchy among wooden coffins at the site seemed to show a transitional phase at the beginning of the Edo period to the strict hierarchy established in the middle 17th century.