EAST ASIA HAD EARLIER LEVALLOIS TOOL-MAKING

A new study of stone tools from a cave site in China shows that sophisticated "Levallois" tool-making techniques were present in East Asia at a much earlier date than previously thought. The findings challenge the existing model of the origin and spread of these techniques in East Asia, with implications for theories of the dispersal of modern humans around the world. The study, by researchers from the University of Wollongong (UOW), University of Washington, Peking University, Chinese Academy of Sciences and China's Bureau of Cultural Relics Protection, is published online in Nature on 19 November.

Examples of Levallois technology (named after a Paris suburb where tools made with this method were discovered) have been found in Africa and Europe dating back to around 300,000 years ago. Before now, the earliest examples of Levallois techniques in East Asia were dated to 40,000 – 30,000 years ago; the new study places them there as far back as 170,000 years ago. Associate Professor Bo Li from UOW's Centre for Archaeological Science, one of the paper's corresponding authors, said the researchers analysed 2,273 stone artefacts excavated from Guanyindong Cave in southwest China in the 1960s and '70s, and found 45 artifacts (four tools, eleven cores and thirty flakes) that show Levallois-style knapping.

"Levallois technology is a step up from earlier stone tools because it involves a level of planning, of preparation, and a repetition of technique" Professor Li said. "Instead of hitting two stones together and picking up whatever looks useful, for Levallois tools you first have to prepare the core to make it a special shape before you knap the core to produce a flake that can be used for cutting or scraping. "Earlier stone tools are more arbitrary in size and shape. Levallois tools are more standardized.

Previous dating at the site, using uranium-series dating, had indicated an age between 240,000 and 50,000 years ago, but had focused on fossils and carbonate samples found away from the stone artefacts. The team returned to Guanyindong Cave to do further dating using optically stimulated luminescence (OSL), which measures the time since the artefacts-bearing sediments were last exposed to sunlight.

"Dating for this site was challenging because it had been excavated 40 years ago, and the sediment profile was exposed to air and without protection, so trees, plants, animals, insects could disturb the stratigraphy, which may affect the dating results if conventional methods were used for dating" Professor Li said.

The question of whether Levallois techniques were invented independently in East Asia won't be resolved until further archaeological evidence is uncovered, Professor Li said.


Read more at: https://phys.org/news/2018-11-stone-tools-analysis-theories-human.html#jCp