An analysis of over 4,000 stone artifacts discovered on an island off northwestern Australia provides a snapshot of Aboriginal life tens of thousands of years ago.
At that time, sea levels were low enough to expose the continental shelf between Australia and what is now Barrow Island, a 78-square-mile territory about 37 miles off Australia's northwest coast. Thousands of years ago, it would have formed the high plateau of a vast, continuous plain spanning over 4,200 square miles , Zeanah told Live Science.
Over three years, they examined 4,400 slicing, cutting and grinding tools from a mix of sites. What surprised the researchers was the variety in the artifacts' compositions. Most of the tools found in caves were fashioned out of limestone, the most abundant geological material on the island. Those discovered at the open-air sites, by contrast, were made mostly from rocks, including igneous and sandstone, that matched sources on mainland Australia.
This diversity is significant because it reveals details about the people who frequented Barrow Island, Zeanah said. "This was probably not like a single group of people moving seasonally across the plains," Zeanah said."The area is vast. The materials may have been transmitted by trade, or by Aboriginal people going from group to group. So that implies a social network."