Aerial surveys can detect Magnetism, Radioactivity and Densities of rocks. These are shown by colours according to the key shown on the map (Density currently needs to be added). So these surveys will easily find Iron, Nickle or Uranium whilst other minerals might show small traces but the density analysis you are shown will give clues to other potential minerals below ground. If you believe you have found something then you need to do a ground survey that will get you a more detailed analysis of the area in question. Once again there will be a time delay before you get the results and you can view an example of them at the Ground Survey Results.
Any comment welcome at email@example.com