Prof Christopher Ramsey

Abstract:

Radiocarbon (¹⁴C) is essential for creating chronologies to study the timings and drivers of pivotal events in human history and the Earth system over the last 55,000 years. It is also fundamental as a proxy for investigating solar processes, including the Sun’s potential for extreme activity. Until now, fluctuations in past atmospheric ¹⁴C levels have limited the dating precision possible using radiocarbon. However, the recent discovery of solar super- storms known as extreme solar particle events (ESPEs) has driven a series of advances with the potential to transform the calendar age precision of radiocarbon dating. Organic materials containing the unique ¹⁴C ESPE signatures can now be dated to annual precision. In parallel, the search for further storms using high-precision annual ¹⁴C measurements has revealed fine- scaled variations in radiocarbon that can improve calendar age precision, even in periods that lack ESPEs. Furthermore, the newly identified ¹⁴C fluctuations provide unprecedented insight into solar variability and the carbon cycle. Here, we review the current state-of-knowledge and share our insights on these rapidly developing, diverse research fields. We identify links between the radiocarbon community, archaeology, solar physics, and Earth science to stimulate transdisciplinary collaboration, and propose how users may take advantage of these recent developments.

Abstract:

The Feeding Anglo-Saxon England (FeedSax) project applied scientific methods to bioarchaeological remains, in order to shed new light on medieval English agriculture. The methodology included an extensive radiocarbon dating programme which, besides helping to date developments in farming at selected case study sites, proved informative in its own right. This paper discusses the key implications of this programme’s results, with regard to the general problems of dating medieval settlement phases. First, it has allowed us to devise a new ‘universal’ chronological schema which aligns conventional phases with the precision currently attainable from calibrated radiocarbon dates. Second, it has revealed frequent discrepancies between the radiocarbon dates of organic remains and their original phasing — usually based upon associated ceramics — often resulting in chronological refinements or revisions, and sometimes revealing hitherto unrecognised periods of activity. In particular, the results highlight that ceramic-based phasing often underestimates the age of organic remains.