The Donghulin Woman from Western Beijing: [sup.14]C Age and an Associated Compound Shell Necklace

Article excerpt

Introduction

Donghulin village is situated in the Western Hills area of the District of Mentougou, Beijing, at latitude 39 [degrees] 58'48" N and longitude 115 [degrees] 43'36" E, 455 m a.s.l. The village is about 80 km away from Beijing City (FIGURE 1). The Donghulin site was discovered in 1966, but no detailed study has ever been carried out (Zhou et al. 1972; Hao 1988). Recently a woman's skeleton was found at the bottom of the Holocene Loess on the rear margin of a second terrace near Fenpo Gully, just west of the village. Interestingly, there were numerous gastropod shells preserved together with the skeleton. And about 25 m away, abundant vertebrate skeletons (mostly fragmented bones) were found in the lower part of an early Holocene soil layer. The vertebrate bones were apparently refuse because some bones were smashed, and with stone hammering blocks. We report here the [sup.14]C dating of the human bones and the shell and discuss the environmental significance of these gastropod shells.

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[sup.14]C dating of the human bones and the gastropod shell

[sup.14]C dating of the human bone and shell samples was conducted using accelerator mass spectrometry (AMS) at Peking University, China and Lawrence Livermore National Laboratory, USA. Samples were pretreated and converted to [CO.sub.2] as follows. Shell sample was treated at Lawrence Livermore National Laboratory: first leached with HC1 to remove secondary carbonate and then hydrolysed with 70% phosphoric acid. At Peking University, bone gelatin was extracted using a standard procedure (Yuan et al. in press). At Livermore, bone collagen was extracted and ultra-filtered using procedures described in Brown et al. (1988). At both laboratories, organics were heated under vacuum with CuO, and the [CO.sub.2] samples were converted to graphite. The targets were measured using standard AMS techniques. The results are shown in TABLE 1.

TABLE 1. AMS [sup.14]C results of the Neritna violacea gastropod shell
and the human phalanx bones of the same skeleton from Donghulin,
Beijing. The Libby half-life of 5568 years is used at both laboratories.
The OxCal 3.3 and INTCAL 98 curve has been used for calibration (Stuiver
et al. 1998).

lab sample no.(1)   material     [Delta] [sup.13]C   [sup.14]C age
                                       (PDB)            (yr BP)

BA-95068            bone              -18.44(2)        8720 170
CAMS-30912          bone              -18.44           8450 70
CAMS-31482          bone              -18.44           8450 80
CAMS-30732          shell             -9.95            8150 60

lab sample no.(1)   calibrated date ([+ or -] 1s)
                    (cal BC)

BA-95068            8160 (0.05) 8133
                    8078 (0.01) 8072
                    8057 (0.01) 8050
                    7969 (0.92) 7586
CAMS-30912          7580 (0.68) 7513
                    7457 (0.01) 7456
                    7507 (0.27) 7478
                    7388 (0.05) 7382
CAMS-31482          7582 (0.90) 7476
                    7388 (0.06) 7380
                    7460 (0.04) 7454
CAMS-30732          7260 (0.43) 7170
                    7150 (0.57) 7030

(1) Samples with a BA prefix were analysed at Peking University, China;
those with CAMS, at the Centre for AMS, Lawrence Livermore, National
Laboratory of USA.

(2) Not measured, assuming that it was the same as that of CAMS 30912.

Two points should be noted from the data of the table.

1 The [sup.14]C bone dates of both laboratories differ somewhat. However, they are generally in agreement at about [+ or -] 1 [Sigma] level. We take the average of the three [sup.14]C bone dates measured at the two laboratories, i.e., 8540 BP as the age for the Donghulin woman.

2 The shell date is younger than the bone dates. Logically speaking, the shell age should be the same as or older than that of the human bone since the necklace is definitely associated with the woman's skeleton and should be her possession. …