‘Uranium dating has been enormously important,’ he underlines.Like we recognise art as quintessentially human, we also consider tool use and technological progress to be defining for our species, and it was as important to ancient humans as it is to us.[but] if you haven’t got organic pigment in there, you can’t use radiocarbon and you’d be destroying the art, which is very valuable.To take a normal radiocarbon sample would be unduly disruptive,’ he explains.
At death, the exchange stops, and the carbon-14 then decays with a known half-life, which enables scientists to calculate the time of death.The first excavations in the 1950s and 1960s revealed a hub of ancient human activity, spanning thousands of years’ worth of artefacts.Unfortunately much of it originates from outside radiocarbon dating’s timescale. was almost non-existent,’ says Geoff Duller, a geochronologist from the University of Aberystwyth in Wales.It’s possible to measure the ratios of uranium-238/uranium-234 and thorium-230/uranium-238, the latter of which depends on the former.Since only uranium, and not thorium, is present at sample formation, comparing the two ratios can be used to calculate the time passed since the sample formed. Pike’s team are not actually dating the painting itself, but small calcite growths on top of it.