Metal Detecting and Treasure Hunting

A 10-year-old boy found a centuries-old medieval "Priory Seal Matrix" used by priests. The seal was marked "Seal of the Priory and Convent of Butley, of Adam, Canon Regular" in Latin. Not a bad find, only 5 inches below the surface!Original Article

First off, no offense to the Chilean miners that just spent an unbelievable amount of time underground and didn't lose their minds. That took extreme bravery!But, think about this: the first rescuer had to go the OTHER way!! He had to go almost 5 miles down. Down, way down, way (way way) way too far down  in a way too thin rock tunnel bored through unstable rock in an unlikely contraption that has only been tested with non-live cargo up till now.I've never considered myself claustrophobic in the slightest, but when I watched the guys face as the capsule slowly slides into the dark, I found that I finally grok the cold fear of claustrophobia.I don't think I could have done it myself. (Sure, I'd bluster with false bravado about it maybe, but just as the capsule starts going into the tube, I think I'd probably fully wuss out.)This guy is BRAVE. Not saying he's not scared. He is, you can see it clearly. But the bravery overrode the fear. I'm impressed.http://cnn.com/video/?/video/world/2010/10/12/vo.chile.rescuer.lowered.cnn

One interesting thing in Illinois was that the detector apparently picked up on a large (about 5" diameter) underground tree-root. It was at the beginning of the spring, a week or so away from the leaves budding out, so the roots had have begun "filling up" with water & nutrients, to get ready for the intense activity of the next few weeks. We dug down about 4 inches, where we first encountered the root. We found nothing, but accidentally injured the root, which began "bleeding" (sap/water).      We ran the detector over the area again, and found that the "target" had moved. (We were initially thinking that there must be something buried _underneath_ the root.) We dug in the direction that the target had moved, thinking that we must have disturbed its location while digging. We dug along the root some more, along the root, towards the tree. (Taking more care as to not damage the root any more.)  We still found nothing. We ran the detector over it again. It had moved even closed to the tree.      We did this a couple more times, then realized that it must have been some kind of mineralization in the root itself (or something to do with the root anyway) causing the non-existent target to move. (Either that or something like a mole with a ring around it's neck :) )

I got one for my birthday. I like it a lot, but am kind of confused on the different controls. I live in an area (Omaha, Nebraska) with a lot of junk in the soil (Bottlecaps, cans, etc.). I crank the discriminator up to maximum, and still get all kinds of false readings. I would think that at maximum, I should get little, if any, readings.     I tried it in my friends yard in Bement, Illinois. He had very little junk in the yard. The detector worked great there, it took us about 20 minutes to find about 5 coins. (Even a wheat penny in relatively good condition.) This proved to me that the detector works fine, but still leaves me confused about what could be making the discriminator work so strangely in my own yard.Anyone have any ideas on what I may be doing wrong?