[Bonetools] Bone projectile points with burned tip

[Katherine M. Moore]

Dear Colleagues:

I have seen very light discoloration from heat on the working ends of  
a few bone tools from Formative Bolivia. The tools involved were  
mostly scrapers and scoops. Experiments in wood fires (at sea level)  
suggested that this kind of heat alteration could be produced very  
rapidly (within 30 seconds). Producing a dark brown color doesn't  
appear to weaken or embrittle a piece made from fresh bone. I believe  
that the pieces I have observed were altered during use (while  
cooking, adjusting burning material in a hearth, working with some  
organic material such as wood being heated during craft production) or  
were exposed to heat after discard. I have also seen some weaving  
implements and small engraved pieces that may have been deliberately  
exposed to heat after burning: to decorate? to ritually transform?   
Indeed, in later periods in South America pyroengraving is seen on  
complicated bas relief incised tubes for apparent ritual use.

Nothing I have seen suggests that the burning has been used as part of  
the manufacturing sequence.

I hope that others have more observations that would help us  
understand these processes.

best wishes,

Kate Moore

Quoting Jean-Marc Petillon <petillon at univ-tlse2.fr>:

> Dear all,
>
> I am forwarding a question from Mat