Rant: I figured the burned layer at that dig near Tucson was just fire damage, then a bone needle changed my mind
Two summers back I helped sift at a site outside Tucson and kept finding charred bits I brushed off as campfire leftovers, until a lab tech showed me a 3,000 year old bone needle in the same layer. Turns out that ash was a workshop floor, so how do you all tell a cooking fire from a toolmaking one when the dirt looks the same?
What did the ash itself look like under a scope, because that seems like the real tell here. Cooking fires and knapping fires would leave different stuff in the mix, like bone fragments, fat residue, or tiny flakes from tool work. A bone needle sitting in the layer is one thing, but was there a whole cluster of tool waste nearby or just that one piece? And did the lab ever run any kind of test on the sediment to back up the workshop idea, or was the needle alone enough to flip the story?