Heat treatment in the news (again!)


November 02, 2020

Heat treatment is the process whereby our ancient ancestors, baked Stone to make the source material for stone tools better suited for the task at hand. See “Heat treatment makes better stone tools" paper, published in August 2009, based on research in South Africa, claimed heat treatment was evidenced as early as 162,000 years ago.

In recent weeks, a paper published in the journal Nature Human Behavior by researchers from the Weizmann Institute for Science, announced they had created computer models  and applied their techniques to stone found in Qesem Cave in Israel. The paper, titled “Estimating temperatures of heated Lower Palaeolithic flint artefacts” by Agan et al. claims  three detectable temperature levels of heat treatment and evidence of this occurring as early as 300,000 years ago.

The computer models created by the Israeli researchers show that different temperatures were used in the fashioning of different tools. Phillip Natalio, one of the authors of the Weizmann institute paper,, quoted in an interview on NPR, said “And that, for us, was very striking because we were able to actually see behaviors that  when they wanted to produce one type of tool, they would use one type of approach. But then if they wanted to fabricate another type of tool, then they would use another protocol.”

"And that's suggestive of controlled stone tool heat treatment - suggestive but not conclusive,” said Dr. Curtis Marion, Foundation Professor with the Institute of Human Origins at Arizona State University, in the same NPR interview.

(Who "they" were was not made clear in the Nature paper but it is surmised they were either late Homo heidelbergensis or early Neanderthals.)

Listen to and read the full NPR interview.