Researchers at Queen's University in Northern Ireland have helped produce a new archaeological tool which could answer key questions in human evolution. The new calibration curve, which extends back 50,000 years is a major landmark in radiocarbon dating - the method used to establish the age of carbon-based materials. It could help research issues including the effect of climate change on human adaption and migrations.
     The project was led by Queen's University Belfast through a National Environment Research Centre (NERC) funded research grant to Dr Paula Reimer and Professor Gerry McCormac from the Centre for Climate, the Environment and Chronology (14CHRONO) at Queen's and statisticians at the University of Sheffield. The curve called INTCAL09 not only extends radiocarbon calibration but also considerably improves earlier parts of the curve.
     Dr Reimer said: "The new radiocarbon calibration curve will be used worldwide by archaeologists and earth scientists to convert radiocarbon ages into a meaningful time scale comparable to historical dates or other estimates of calendar age. It is significant because this agreed calibration curve now extends over the entire normal range of radiocarbon dating, up to 50,000 years before today. Comparisons of the new curve to ice-core or other climate archives will provide information about changes in solar activity and ocean circulation."
     It has taken nearly 30 years for researchers to produce a calibration curve this far back in time. Most experts consider the technical limit of radiocarbon dating to be about 50,000 years, after which there is too little carbon-14 left to measure accurately with present day technology. Further information on the work of Queen's Chrono Centre can be found online at chrono.qub.ac.uk

Sources: EurekAlert!, ScienceDaily (11 February 2010)