That's for uniform distributions. We don't know the distribution here, that's part of the problem, but I would expect early cave art to be more sparse and worse preserved.
Wouldn’t it make just as much sense that once a site reaches X age it will likely make it to 10X since the conditions that allowed it to get to X are slow to change?
Wouldn’t it make just as much sense that once a site reaches X age it will likely make it to 10X since the conditions that allowed it to get to X are slow to change?