Spent 3 months trying to date a single clay sherd from a dig near Tucson

Honestly, I picked up this tiny piece of painted pottery from a Hohokam site back in April and thought I'd have it carbon dated in a week. Nope. The lab kept pushing back because the sample was too small and had root contamination. Took until last Tuesday to finally get a result, and it turned out to be from around 1100 AD. Has anyone else dealt with labs dragging their feet on small samples like this?

2 comments

2 Comments

drew9062d ago

What kind of pretreatment did the lab use on that root contamination? I've heard that some labs just run a standard acid-base-acid wash and call it good, but with desert soils in the Southwest you often need a more aggressive approach like a heavy liquid separation or even a full alkali extraction. If they didn't do that, there could still be old carbon from the roots skewing your date a bit. Was this a pure AMS run or did they do any stable isotope work to check the sample quality?

terryallen2d ago

Wait, they ran a standard acid-base-acid on desert root contamination? That's insane, those roots can be ancient and totally resistant to that.