The upper right of the screen is the primary areas for silver and copper. However, a coin, jewelry, and other good targets can be anywhere on the screen. Gold rings both larger and small plus 5 cent coins are can well be down at the bottom right half of the screen. Anytime we discriminate by blacking out parts of the screen we take that chance of missing good targets.
A one way hit is most likely not a coin which is about all we can say in that area. However, I have dug coins and other good target that only hit one way because of co-located targets but not often.
It is difficult to tell a user how much to discriminate or how little. As an example there are times when I hunt an old school from the forties. There is a lot of trash there but not any real old coins from in the 1800 area. I will use a discrimination pattern to cherry pick through the trash. I also hunt the site of an old indian trading post that was built around 1790 to 1820 or so. I use IM-14 and work through the iron to find the really good deep targets and at times will slowly go through with IM-16.
From what I read of your setting I would be most concerned about missing gold jewelry and even that gold coin. <STRONG>Most often they would fall on the right side of the screen but can be on the left side.</STRONG> It <STRONG>comes down to detecting all targets and going by coins as the most accepted way to find the most good targets if you can do so by using the tones.</STRONG>
HH, Cody