Origins of the Stonehenge Altar Stone (Geology Section)

A talk by Prof. Richard Bevins.

Richard Bevins gained his first degree from Aberystwyth University and completed his PhD at Keele University. His research focussed on the mineralogy and geochemistry of Lower Palaeozoic volcanic rocks in north Pembrokeshire. Following completion of his PhD Richard was appointed as Assistant Keeper of Geology at the National Museum of Wales, over the following 40 years occupying the posts of Keeper of Geology, Keeper of Natural Sciences and finally Director of Collections and Research. Over the last 15 years Richard has focussed his research attention on the Stonehenge bluestones, identifying source outcrops in west Wales, as well as the spectacular discovery that the Altar Stone came from northeast Scotland. Richard is an Honorary Professor at Aberystwyth University and is a Fellow of the Learned Society of Wales.

It is over a century since geologist H.H. Thomas proposed that the Stonehenge bluestones were sourced from the Mynydd Preseli area in west Wales. We have applied a range of modern analytical techniques, not available to Thomas, to investigate the petrology, mineralogy and geochemistry of the bluestones, confirming a west Wales source for the majority of the stones. We have been able to pinpoint exact rock outcrops from which stones have been extracted. However, one ‘bluestone’, the Altar Stone, is anomalous in many ways when compared with the west Wales stones and a source in the Orcadian Basin in northeast Scotland has recently been identified. This has ramifications for understanding interconnectivity between Neolithic communities in Britain and Ireland, as well as the significance of Stonehenge itself.