Once thought to have originated in Wales, like the rest of the 4,500-year-old monument’s bluestones, Stonehenge’s altar stone has recently been traced through geological fingerprinting to Scotland. The question of how the megalith made the 435-mile journey from there to Salsbury Plain in England is now the focus of a study by scientists at Curtin University in Australia in collaboration with experts from Sheffield Hallam University, the University of Sheffield, Wessex Archaeology, and the University of Bristol in the United Kingdom.  Their findings were published June 4 in the Journal of Quaternary Science. Related Articles Stonehenge was built in stages by Neolithic and Bronze Age peoples between around 3,000 BC and 1,500 BCE. It consists of an outer circle and inner horseshoe of sandstone trilithons with inner arcs of smaller bluestones. The altar stone at its heart is thought to have been placed there during the second period of Stonehenge’s construction, between 2,620 and 2,480 BCE. Geological evidence has confirmed that the monument’s sandstone boulders came from the Marlborough Downs, 20 miles away, while its …