Ann: Exciting New Nickel Discovery at Sabre Prospect, page-33

Not an expert by any means but the "EM" in the VTEM acronym would mean ElectroMagnetic .
A plane flying (moving) over the ground sends a pulse of electricity to the ground to measure if the ground is magnetic and at what depth it is magnetic .
Magnetite a form of iron ore is magnetic and will show up as an annomaly (something out of the ordinary) on a map charting magnetic responses , where as hematite another form of oxidised iron ore is not magnetic and will not show as an EM response but may be above the magnetite and still contain base/precious minerals
Iron ore is often associated with base mineral deposits ie IOCG (iron ore copper gold deposit )

My guess is they should do a gravity survey , if you overlay a gravity survey over a VTEM survey it helps to validate that there actually is a heavy (dense) (higher specific gravity ) lump of iron ore, rich in minerals under foot

The method of discovery was pioneered by WMC about 50 years ago
A professional can correct my above assumptions if they wish.