And are they any use to help find gold?
The warmer colors (pink, red, orange) indicate a high magnetic field strength. The cooler colors (blue, green, yellow) show low magnetic field strength.
The warm colors could represent volcanic rocks, areas on and adjacent to faults (reefs).
Cool colors sedimentary rocks though these may also show hot if they have abundant magnetic sands.
Many thanks Lepresean! Iām guessing that with gold being non-magnetic that areas with a strong gold presence would be a cooler colour.
Not necessarily. Faults and or reefs can come up hot, sedements, cool. You have to overlay the geology and known gold occurrence to gain a better understanding. I dont fully understand it by a long shot and find it confusing as the data seems contradictory in some places. It can also show other geological structures that are ancient and within a regonal rock type that are not obvious to the naked eye. I find it useful when looking at volcanic cap rocks that have preserved sedimentary rocks beneath. This is a good example as the volcanic rocks show up hot and the gold bearing sedements beneath show up cool.
Anyone else want to chip in their 5 cents on this topic? Would be appreciated.
Cheers for that - a lot to learn about it.
I came across this, but you probably have to.
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/magnetic-survey#:~:text=A%20magnetic%20survey%20can%20map,features%20(Stevens%2C%202010).
JW 
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JW
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This could send you down a rabbit hole. 
https://www.researchgate.net/publication/272487686_Understand_magnetic_maps
JW
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