Actually if you look at the description of the MMI you will see that depth is also indicated using this technique...... Not a definative indicator of the size of a mineralized body.... but one more tool that can help define where to drill....

When used in conjuction with airborn, ground geo....... etc

Target defition is improved... and thus more likely is the sicess on drilling.... I would hate to see PRB plunk 10 or 20 holes in the ground before they hit something..... MMI will improve the odds... as will the ground geo......

Also the more info that NOT comes up with in deining their deposit the better..... this helps in the understanding the dynamics of the deposit..... hopefully "deposits"