Redrock alteration is commonly associated with large Iron Oxide Copper-Gold (IOCG) deposits and sometimes with Prophyry copper-gold deposits. Mapping the distribution and intensity of the alteration can tell you a lot about how big the system is and where the ore is likely to be. These examples come from the Cloncurry area, east of Mount Isa in northern Australia.
0:00 Redrock and ore deposits
0:21 Example in Calcsilicate rocks
3:09 Example with secondary magnetite
4:27 Zoning and ore
