iron patch, you are obviously coming from the perspective a dig-all environment. Ie.: relicky spots like furroughed fields, or beach hunting, or something like that. In those cases, sure, dig all except iron (or dig even the iron too if you REALLY want to be hard-core and not miss anything
). And perhaps you think because these have been your only hunt type spots, that it's simply inconceivable that anyone would pass foil or tabs or something. Or to pass surface pennies and chase only the deeper stuff (because turf tends to be stratified by age). In all those mentalities, I can see where you're coming from. You would bristle and thought of any notching or disc. at all, etc....
But there are places, believe it or not, where sometimes we need to be a little selective, and time and sanity just don't allow a "strip-mine" philosophy. Here's one example: They tore down the grand-stand bleachers of some 1920s era stadium seating in my town. Underneath these grandstands had been hard-pan dirt. For 70+ yrs. people pushed their trash through the open-slatted wooden seating, to rain down on the under-belly below. Naturally the clutter would be cleaned and raked out after each event, but you can imagine the sheer volume of coins, tabs, foil, etc... which had built up over the years in this hardpan layer. When the demolition started, the tractors disturbed and pushed around this layer, while they dozed out all the structure. It was a silver bonanza for those of us who got in on it! But wait: all those years of soda and beer drinking fans had also sent millions of tabs and such down too. If a person thought they were going to be a "hero" and hunt for nickels or whatever, he was going to be a sorry fellow indeed. You'd have never have progressed out of a 10 ft. square area! And if rings/jewelry was your goal, time would be better spent just going to the beach, as the junk ratios would be mind-boggling here. Add to that that the multi-acre area was slated to be filled with fill-dirt by the end of the week, so it was all we could do to race through with little coils, and high disc, and pick out all the coins. You just couldn't have it both ways. You can see in a situation like this, that either notching, or at least mentally picking and choosing based on tones, was highly desirable. In fact, I even got a $5 gold piece in the mess of trash, because as it turns out, they read slightly higher than the square tabs I had edited out in my disc. pattern (very close, yet apart enough to be separate
)
So be aware that there is some places where playing the odds a little does pan out. In other areas (beaches, relicky sites, etc....) you're right, dig all.
