Ok heres something that mite be helpfull for some. Im sure others may know this, but ya know. Dig in your pocket at different times, look at the change you may have in there. How many times do you have coins from 30 or 40 years ago? Its 2009, 1964 was last year for silver coins. Thats 45 years ago and you occasionally get some back in change from the coffee you bought, rite. Now with that concept in mind, say you go metal detect a church or store or the like thats not that old, say the 1960's. Now how many coins got lost from then that they were 30 or 40 years old? Say in 1965 some1 had a 40 year old "left over" coin and lost it, that makes it 1925 in an area, thats not that old. So a site thats not that old MAY produce old silver. Now imagine you find a site thats 1870's or 80's. Go back 30,40 or more years. I found an 1840 dime in an area that had structures there in the 1940's. How it got there i have no clue, but i also dont think it was connected with one another. 100 years is kinda too far apart, but you never know is the point. N there you have it.