Hi Duker, for my input let me rephrase your question to read " WHY IS SO MUCH GOOD STUFF ON TOP ? "
I reducing surface only hunting to VERY OLD points in the leaves and grass roots, well over what may be deeper....At least 3 places we have dug in the last 5 years, the camp has been at the foot of a hill
So now you can see whats comming....there was ALWAYS a reason to be up on that hill.....cooler, less smoke,view OR just to get away from the adults [ 20 year olders ]. In any case whatever got left or dropped on that hillside could take THOUSANDS of years to work down to the flatter soil now covering a camp area with bird points [500 yrs old ].
We considered it a great bonus to be finding nice random points while heading for the depths !
Thats probably the kind of story you were expecting from a digger named "Shallow Hal " ! ! ! ! !