Geology and tectonic setting of the Indonesia region are part of the crustal plates evolution products occured in the marginal continents of Asia and Australia. These situations have created two distinct environments imply in the mineralization systems, i.e, continental and arc island mineralization systems respectively. Metallic mineralization types in the Eastern parts of Sumatera, Kalimantan, Irian Jaya, and Timor are generally the products of the continent-crustal plates collosion. Base metal minerals deposition in the regions are frequently skarn, vein, and rarely porphyry types occured in association with the Paleozoic to Mesozoic sedimentary and Mesozoic to Cainozoic acid-intermediate intrusives rocks. Porphyry, massive lenses, and vein types are commonly deposited in the inner zones of arc system and they generally hosted by intermediate to basic intrusives and related volcanic rocks of Mesozoic to Cainozoic ages. These types distribute over the Western part of Sumatera, Java, Maluku, Sulawesi, and Nusatenggara. With an exception of tin, there are twenty eight sulphides deposits have been discovered during the Duch time up to recent exploration activities. Total ore reserves is about 1,408,812,000.93 tonnes equal to 10,169,954.66 tonnes of copper, 684,507.62 tonnes of lead, 1,275,894.97 tonnes of zinc, 6,306;282.99 tonnes of mercury, 120,000.00 tonnes of molybdenum, 827.98 tonnes of gold, and 1,836.19 tonnes of silver. Two of deposits are The Grasberg porphyry copper-gold and Ertsberg copper-gold deposits in Irian Jaya recently being operated by PT. Freeport Indonesia.

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