Yet Another Example of Ancient Tech

on August 13, 2009

A few months ago, I discussed recent findings on the ancient use of fire to produce a kind of glue which was used to attach stone axe heads to wooden handles. Now another early example of the sophisticated use of fire in tool-making has been described — and like the glue, it comes from South Africa and has been dated around 72,000 years ago.

The technique in question involves heat-treating a yellowish stone called silcrete, which is not well-adapted to tool-making, so that it turns a deep, glossy red and is very easily flaked.

According to a press release from Arizona State University:

“Our illumination of the heat treatment process shows that these early modern humans commanded fire in a nuanced and sophisticated manner,” says lead author Kyle Brown, a doctoral candidate at the University of Cape Town, and field and lab director in Mossel Bay, South Africa, for ASU’s Institute of Human Origins.

“We show that early modern humans at 72,000 years ago, and perhaps as early as 164,000 years ago in coastal South Africa, were using carefully controlled hearths in a complex process to heat stone and change its properties, the process known as heat treatment,” explains Brown.

“Heat treatment technology begins with a genius moment – someone discovers that heating stone makes it easier to flake,” says Curtis Marean, project director and a co-author on the paper. …

“This knowledge is then passed on, and in a way unique to humans, the technology is slowly ratcheted up in complexity as the control of the heating process, cooling and flaking grows in sophistication,” Marean says.

This creates a long-chain technological process that the researchers explain requires a complex cognition, and probably language, to learn and teach.

This story popped up just as I was working on a post which considers questions of ancient tech and the origins of language, so I’m not going to expound on it here.

However, one thing that did jump out at me was the suggestion that the heat treatment technique could go back as much as 164,000 years, since that is the same figure I mentioned in my earlier post as given by paleoanthropologist Donald Johanson for an extremely early South African site at which composite tools have been discovered.

It is clear that the scientists working at these various sites are starting to get their stories coordinated. It is also clear that we are dealing here with matters of extraordinarily deep time — events compared to which the European cave art of 20,000 years ago was painted only yesterday.


A listing of all my posts on deep prehistory can be found here.

A general overview of the areas of interest covered at this blog can be found here.

A chronological listing of all entries at this blog, with brief descriptions, can be found here.

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