Four new radiocarbon dates of elevated strandlines in tectonically active areas of eastern Indonesia and East Malaysia indicate average rates of uplift that range between 4.5 and 9 mm annually during the past 24,000 yr. These values are at least three times higher than former estimates from eastern Indonesia. Another radiocarbon date from the south arm of Sulawesi—also tectonically mobile—indicates a rate of uplift of 1.4–2.5 mm per year which corresponds with earlier determinations. This particular case, however, suggests that the sample was probably located close to a north-south axis about which southern Sulawesi was tilted during the Quaternary.

In the Langkawi islands, West Malaysia, one of the regionally ubiquitous shorelines at about 2 m above sea level was dated at 2590 ± 100 yr BP which corresponds with Fairbridge's (1961) Abrolhos Submergence.

The addition of organic materials derived from the upper soil layer yields, for samples at greater depth, younger 14C dates than the date of deposition. To find a criterion for the contamination with younger carbon in a soil sample, we examined the radiocarbon concentrations in two humic acid fractions and humin taken from the same sample. The humic acid extracted from a soil sample was divided into two fractions HA1 and HA2. HA1 is the first fraction extracted by 30 minutes' heating with 2 percent NaOH solution, and HA2 is the second fraction extracted by 2 hours' heating with 2 percent NaOH solution after the extraction of HA1. The residue was assumed as the humin (HM).

Many of the peat or soil samples taken from the layer just above the nonpermeable layer contain appreciable amounts of organic materials transported from the upper layer after the sedimentation of the deposits. For the limited number of cases tested here, there is a trend in which the contaminants are selectively extracted by HA1 or HA2. When the soil samples are contaminated the ages of the HA1 and HA2 fractions appeared to differ widely in most cases. Agreement between the HA1, HA2, and HM ages may be used as a criterion for the reliability of the soil dating.

This list continues Gakushuin VII (R., 1969, v. 11, p. 295–362); the same instruments and techniques were employed. Age calculations are based on the Libby half-life of C14, 5570 ± 30 years, and the modern activity given by 95% of the activity of NBS oxalic acid standard. Errors quoted are the standard deviation obtained from the number of counts only. When observed activity is less than 2σ above background, infinite date is given with a limit corresponding to the activity of 3σ. For shell samples, dates are computed without any correction for environmental and biological isotopic fractionation. The description and comments are essentially those of the submitters.

This list continues Gakushuin VI (Radiocarbon, 1967, v. 9, p. 43-62), the same instruments and techniques having been employed.

Age calculations are based on the Libby half-life of C14, 5570 ± 30 years, and the modern activity given by 0.95 Aox, i.e., 95% of the activity of NBS oxalic acid standard. The errors quoted are the standard deviation obtained from the number of counts only. When observed activity is less than 2σ above background, infinite date is given with a limit corresponding to the activity of 3σ, and when it is greater than 0.95 Aox −2σ, modern date is given with a limit = 0.95 Aox —3σ. For shell samples, dates are computed without any correction for environmental and biological isotopic fractionation.

The description and comments are essentially those of the submitters.

This list of dates is a continuation of Gakushuin V.Instruments and techniques are essentially the sameas those used for Gakushuin III, IV and V.

This list includes many of the datings done from September 1964 to October 1965. The instruments and techniques used for this work are essentially the same as those used previously (Gakushuin III). Bone samples were dated on the organic materials obtained by the following procedure. After washing with distilled water the powdered bone samples were boiled with 10% H2SO4 solution 10 to 40 hours. The extract, a clear solution, was exaporated to almost dryness, and, after concentrated H2SO4 was added, heating was continued until most of the organic compounds became insoluble carbonized or polymerized material. The black residue was washed in water and treated as the usual charcoal sample for dating.

This list includes many of the datings done from November 1963 to October 1964. The instruments and techniques used for this work are essentially the same as those used previously (Gakushuin III).

This date list covers many of the datings done from November 1962 to October 1963. The instruments and technique used for this work are essentially the same as those used for the previous work (Gakushuin II). Age calculations are based on the Libby half life of C14, 5570 ± 30 yr. The errors quoted are the standard deviations obtained from the number of counts only. When observed activities are less than 2a above background, infinite dates are given with a limit corresponding to the activity of 3σ, and when they are greater than the activity of 95% of NBS oxalic-acid standard minus 2a, modern dates are given with the limit equal to 3a below the 95% of NBS standard.

This date list covers many of the datings done from November 1961 to October 1962. Technique described in Gakushuin I (Gakushuin I) is virtually unchanged, using 900-ml acetylene-filled proportional counter (Counter 1) with multiple-anode anti-coincidence ring counter.

Natural C14 measurements have been performed at Gakushuin University since 1959, using a proportional counter of 400 ml (Kigoshi and Tomikura, 1960). The counter presently in service is made of copper tubing and has an effective volume of 900 ml. Acetylene gas is used as counting gas at pressure 600–760 mmHg and prepared in the same way as in the case of 400 ml counter. The counter is shielded by iron sheets of 23-cm thickness and by anti-coincidence with a multianode propane-flow proportional counter of Houterman's type (Houtermans, 1958). A background of 5.6 counts/min has been attained with this counter arrangement. The modern carbon sample filled at 0°C and 760 mmHg shows an activity of 11.8 counts/min. The samples with code numbers greater than GaK-60 were measured by this counter.