I understand what you're saying about selling them. I do agree, knappers can produce these items fairly quickly. However, when it comes to dating these items, it's done via archeologist and not geologist. We've spent millions if not a billion dollar over the years on digs all over the world. They methodically map out and dig historical sites and catalog every little item they find. Dont discount these folk's life work. It's not that difficult to align the information from digs all over the place. It comes down to what new items are found at the different levels of the dig. For instance, we know when pottery was introduced in societies. It is harder to pin point the exact time hence the periods are done now in thousands of years verse even down to hundreds of years. When you get into say the last one to two thousand years ago, they can add the hundred market.