Radiocarbon 51 (1)

Reviews developments in radiocarbon measuring techniques from the Libby counter through proportional gas counters and liquid scintillation spectrometers to the more recent developments of accelerator mass spectrometry (AMS), followed by a coupling of gas chromatography with AMS for compound-specific 14C analyses.

Discusses the reasons behind a change in the magnitude of calendar age-radiocarbon age offsets, in particular during the last glaciation. PP-B

Presents some of the most significant results in establishing a chronology for Old World archaeology, based on 14C dating performed during the last 50 years.

Introduction to the fundamental assumptions on which radiocarbon dating is based, and how they lead to the need for calibration. PP-B

Discusses a few historical aspects of the author's participation in the journal and its field of science, on the occasion of Radiocarbon's 50th anniversary. Au/PP-B

Presents radiocarbon results from modern South Pacific corals from the Marquesas Islands, Vanuatu, Papua New Guinea (PNG), and Easter Island. All of the measurements are from pre-bomb Porites corals that lived during the 1940s and 1950s. The data reflect subannual to multiannual surface ocean 14C variability and allow for precise, unambiguous reservoir age determinations. The results are compared with published values from other coral records throughout the South Pacific. The question of how much, and how fast, South Pacific reservoir ages might have varied in the past is addressed by examining a published record from a Pleistocene coral from Vanuatu that lived over a 700-yr period during the Younger Dryas. The average reservoir age at that time was larger than today, by ~150 yr, and exhibited reservoir age variability on a decadal timescale not seen in modern times. Measured paleo-reservoir ages increase sharply in this record by as many as 300 14C yr in 3 decades. These increases are punctuated by smaller reservoir age decreases, on the order of 150 yr. This reservoir age variability provides a rare picture of active ocean ventilation and ocean-atmosphere exchange at the close of the Pleistocene.

Discusses the creation, between 1968 and 1984, of a 7272-yr oak chronology in Belfast, Northern Ireland, in order to provide a local calibration of the radiocarbon timescale. A parallel dendrochronological enterprise in Germany allowed for the possibility of independent replication.