1 Metallic Ore Deposits Metallic Ore Deposits Average Abundance of Ore Metals in Average Abundance of Ore Metals in Earth Earth ’ ’ s Crust s Crust 71 ppm 71 ppm Zinc (Zn) Zinc (Zn) 5.5 ppm 5.5 ppm Tin ( Tin ( Sn Sn ) ) 20 ppm 20 ppm Lead (Pb) Lead (Pb) 20 ppm 20 ppm Nickel (Ni) Nickel (Ni) 350000 ppm 350000 ppm Iron (Fe) Iron (Fe) 25 ppm 25 ppm Copper (Cu) Copper (Cu) .002 ppm .002 ppm Gold (Au) Gold (Au) .050 ppm .050 ppm Silver (Ag) Silver (Ag) Average Abundance in Average Abundance in the Crust the Crust Metal Metal ppm = parts per million = grams per tonne Types of Metals Types of Metals Base Metals Base Metals Metals that oxidize and corrode relatively Metals that oxidize and corrode relatively easily easily Fe, Pb, Zn, Cu, Ni Fe, Pb, Zn, Cu, Ni Precious Metals Precious Metals Metals of high economic value, and which do Metals of high economic value, and which do not oxidize or corrode easily not oxidize or corrode easily Au, Pt, Ag Au, Pt, Ag Requirements for Ore Deposit Formation Requirements for Ore Deposit Formation All ore deposits require the following: All ore deposits require the following: A source of metals A source of metals A means to transport the metals A means to transport the metals A fluid A fluid An energy source (heat or gravity) An energy source (heat or gravity) A means to concentrate the metals at one location in A means to concentrate the metals at one location in an extractable form an extractable form Change in chemical conditions Change in chemical conditions Physical sorting Physical sorting