AMS ¹⁴C Dating Using Black Pottery and Fiber Pottery

Abstract

ABSTRACT.A technique of accelerator mass spectrometry (AMS) has made it possible to directly measure radiocarbon ages of pottery by isolating organic materials sealed in the pottery when the pottery was formed. We analyzed the carbon contents and 14 C ages for "black pottery" from the Philippines and "fiber pottery" from Japan using the relevant carbonaceous materials extracted from the pottery samples, i.e., adhered chaff or grass fibers that were incorporated in the pottery matrix, respectively. The carbon yield of the pottery sample varied largely depending on the pottery types, the preservation conditions, as well as the chemical pretreatment methods to purify carbonaceous materials for 14 C dating. We will discuss criteria for sample selection of well-preserved pottery, and a modified method, instead of the standard alkali treatment, to obtain sufficient material for precise 14 C dating.

Radiocarbon dating of charred human bone remains preserved in urns excavated from medieval Buddhist cemetery in Japan

“…This shift in C/N ratio to the higher value of 9.2, but the ratio is still much lower compared with that of wood material, may be the result of heating bone material at around 800°C in cremation; nitrogen escapes more preferentially than carbon during the heating process that produced charred bone remains. In addition, d 15 N values for charred bone materials ( Table 2) were higher compared with typical values for plants (0-7‰), and consistent with those for human bone collagen [14]. d 13 C values obtained for charred bone samples (À24.6‰ to À22.4‰) were somewhat lower than typical values for bone collagen of À23.5‰ to À20.5‰ [14] for human such as a Japanese Buddhist who preferentially ate terrestrial-plant resources (Table 1).…”

“…In addition, d 15 N values for charred bone materials ( Table 2) were higher compared with typical values for plants (0-7‰), and consistent with those for human bone collagen [14]. d 13 C values obtained for charred bone samples (À24.6‰ to À22.4‰) were somewhat lower than typical values for bone collagen of À23.5‰ to À20.5‰ [14] for human such as a Japanese Buddhist who preferentially ate terrestrial-plant resources (Table 1).…”

“…Although two 14 C ages quite consistent with each other were obtained for samples 4P24-1-1 and 4P24-1-2 that were divided into two from a piece of wood charcoal, the dates for the charred wood are remarkably older compared to the dates for charred bone samples (4P24-2, 4P24-5, shown in Table 1). By Table 1 Amount of sample for combustion, CO 2 yield rate, d 13 C, 14 microscopic analysis (Figs. 2a and 2b), three wood fragments (4P24-1-1, 4P24-1-2, 4P24-3) were identified as Japanese cypress (Chamaecyparis obtusa Endl.…”

“…Therefore, we have searched for charred materials directly among the cremated remains for 14 C dating, and discovered that some parts of heated bones or cremation pyres may sometimes contain charred residues, maybe due to insufficient oxygen supply during the cremation. Thus, we have collected some charred materials from the cremated remains contained in cinerary urns that had been excavated at the cemetery of the Hoenji temple in Ichinomiya-city, Aichi prefecture, central Japan, to estimate the calendar age of cremation in the medieval period by 14 C dating and to compare the obtained numerical ages with the age estimated by preceding typological analysis of pottery vessels.…”

Effect of HF leaching on 14C dates of pottery

“…by Hedges et al [1], quite reliable 14 C dates can be obtained on organic-rich coating, such as from soot or food, preserved on the surface of ceramic vessels. Another possibility is to date large carbonaceous fragments found inside the sherds, like fibres of temper used during pottery manufacturing, or charcoals [2,3]. Probably the best material for 14 C dating is provided by specific lipids chemically extracted from the sherds and then isolated by gas chromatography [4,5], but this technique is complicated, and applicable only to pot fragments that were devoted to culinary use with a lipid-bearing food, and where lipids have preserved well.…”