Radiocarbon and Stable Isotope Analyses on the Earliest Jomon Skeletons from the Tochibara Rockshelter, Nagano, Japan

Abstract

ABSTRACT. This study presents the results of carbon and nitrogen isotopic analyses of six human skeletons excavated from the Tochibara rockshelter (Nagano, Japan). The human skeletons were reported to be accompanied by "Oshigata-mon" type pottery dating to the Earliest Jomon period (8900 BP ~ 6600 BP). A radiocarbon determination from charcoal associated with the human remains was reported to be 8650 ± 180 BP (GaK-1056). However, the depositional context of human skeletons was uncertain because they were recovered by excavations that were dug by prescribed levels. Our results indicated that these skeletons date to the Earliest Jomon period; the 14 C determinations place these remains between 8260 ± 100 BP (TERRAb030799ab38) and 8580 ± 100 BP (TERRA-b011300a35). This coincides with the archaeological evidence that these specimens are some of the oldest Jomon skeletal materials. Furthermore, δ 13 C and δ 15 N values provide evidence for the first reconstruction of the diet of an inland Earliest Jomon population. Although the distribution of data indicated a possibility that they had exploited small amounts of seafood, the isotopic data point to this group having relied heavily on a terrestrial ecosystem based on C 3 plants.

Chronology of the Yayoi skeletal remains from the Kanto district, Japan: a preliminary re-evaluation by radiocarbon dating of postcranial material

“…This is very similar to another estimate of 79 ± 6% derived from apparent 14 C age-differences between human and marine mammal and terrestrial mammal ages (Yoneda et al, 2002b). Furthermore, in the case of the Earliest Jomon population of the Tochibara site in inland Nagano, an average d 13 C of around -19.9 ± 0.3‰, corresponding to a diet of 13% marine food, was consistent with a significant correlation between d 13 C and d 15 N, which suggested that this population exploited not only terrestrial but also other resources with higher isotopic values such as anadromous salmon (Yoneda et al, 2002a). The lowest d 13 C among the Tochibara population at -20.4‰ suggests that the end-point at -21‰ for the C 3 consumer is reasonable for Japanese populations as well.…”

“…Collagen was extracted from bone by using an improved method of Longin (Longin, 1971;Yoneda et al, 2002a). After removing humic and fulvic acids by soaking in 0.1 M NaOH at room temperature, samples were crushed into fine powder with a freezer mill.…”

“…The CO 2 produced was then automatically fed into an isotope ratio mass spectrometer (Finnigan MAT 252 TM ). d 13 C values were measured and used to correct for isotopic fractionation and to estimate protein source (Chisholm et al, 1982;Arneborg et al, 1999;Yoneda et al, 2002a). For the 14 C analysis, 2.5 mg of 'collagen', containing about 1 mg of carbon, was oxidized to CO 2 within evacuated tubes with copper dioxide at 850°C, and then CO 2 was purified cryogenically in a vacuum system .…”

“…Surface ocean water, for example, is on average about 400 14 C years older than the contemporaneous atmosphere because of this 'marine reservoir effect' (Stuiver et al, 1986). A calibration curve mixing the atmospheric (INTCAL98; Stuiver et al, 1998a) and marine data sets (MARINE98; Stuiver et al, 1998b) should be used for each individual sample, depending on the estimated percentage of marine carbon in its collagen (Arneborg et al, 1999;Yoneda et al, 2002a;Bayliss et al, 2004). Arneborg et al (1999) estimated the percentage of marine food in prehistoric diet using a linear mixing of d 13 C value to be between -21.0‰ and -12.5‰, which represent values for pure terrestrial (C 3 ) and pure marine consumers, respectively.…”

Variability in stable isotope ratios in two Late-Final Jomon communities in the Tokai coastal region and its relationship with sex and ritual tooth ablation

“…Numerous studies have employed stable carbon and nitrogen isotope analysis of human bones from the Jomon period (Chisholm et al, 1988;Minagawa and Akazawa, 1992;Minagawa, 2001;Yoneda et al, 1996Yoneda et al, , 2002Yoneda et al, , 2004. Minagawa (2001), for example, investigated differences in diet between a number of Jomon populations.…”