Hi Guys:
Im going to toss you an answer because I am in the mood to confuse myself this morning. It may not be technical enough for some but they can throw in their 2 cents worth and educate us all.
Mineralized ground: Well to the best of my knowledge and from drilling experience in my past the whole big rock were all on is mostly minerals! This makes the whole Rock nearly one big ball of minerals which is pretty well higly mineralized, techinecally speaking. However we are speaking in the terms of metal detecting and calling an area highly mineralized I think should be restated as highly conductive mineralized soil. To metal detectors your talking minerals that pick up and transmit back the signals like metals do because of their mineral make up. Here in Colorado we can pick up lots of rocks called hot rocks and the detectors will sound off like your on top of a railroad track. It is caused form the metalic mineral makeup in the rock. There are several minerals that will cause hot soil so to speak. Here we have iron, iron pyrite, common term, silver, copper and several others. So when you find an area that mother nature left a consentrate of one of these then you get signals reading off the soil itself from its makeup. Like the salt in the beach if you dont turn on the salt elm or hunt in jewl. mode you can get a whaky bunch of signals.
Around here you find the mountains not so hot but the river valleys that washed and collected the stuff for eons to be full of hot spots. Usually can turn down the syns. and hunt ok but I guess in such radical areas you will loose depth, commonly controlled with either a double d coil or a different type detector that I know nothing about, dont even know the name of them but they make ones for nothing but highly mineralized soil.
Hope your not as confused as I am this sunny thursday morning and hope this shed a little light on the term highly mineralized.
Good Luck
Grumpy