From what I was told they can get reasonably close on the date by looking at the edge work on the point and comparing it to other known pieces. This is what I was told they did with my point. I was told that my spear was definitely Palelo period, but I didn't pay to have the more precise analysis done. The difference in the intricacy of the edge work is supposed to be how they tell the difference in age. The older the point, the more crude the edge work. We also find quite a lot of woodland era points. These have very fine edge work. We find quite a few small bird points that are woodland era. Some points we find you can tell were reworked from larger pieces that either broke from use or broke when the maker was in the process of making them. If you are really lucky you might find what is known as a "pinetree". A few people I know have found fully intact pinetree points. Collectors prize these because they are rare and a good one will fetch big bucks at shows if it's authentic. I have one I found in a field that is only a partial and a guy offered me $50 for it. The edge work on these is very intricate and resembles a serrated bread knife. These are usually found in the best condition in rock houses, caves or along the river banks because these type points rarely survive intact after being plowed over in fields again and again.
I meant, what does “11,000 BP” mean?