AUSMEX EVENING STAR | Drill core analysis by professor Ken Collerson 

Epithermal veins form a few hundred metres below the surface. Potassic alteration in IOCG systems forms several thousand metres below the surface. Having both of them in the same core suggests that the epithermal system is much younger. It must have developed after a long period of erosion required to remove several thousand metres of rock above the IOCG system.

Thanks prof ken for this informative vedio

THANKS FOR SHARING ..

Thanks Sir, Is tuff is produce on contact metaphorism.