ADELAIDE, SOUTH AUSTRALIA—Stone quarrying at Sugarloaf Hill in southeastern Australia’s Riverland dates back some 7,000 years, according to a statement released by Flinders University. Researchers from Flinders University and the River Murray and Mallee Aboriginal Corporation said that chert and silcrete were extracted from the quarry to make tools and weapons that were likely redistributed beyond the Riverland. “The key outcome from our researc…