Review of Precambrian Porphyry Cu ± Mo ± Au Deposits With Special Reference to Malanjkhand Porphyry Copper Deposit, Madhya Pradesh, India

Precambrian porphyry type Cu±Mo±Au deposits are present in many parts of the world including Australia, Brazil, Canada, China, Finland, India, Namibia, Russia, Sweden, and Zambia. Most of them are associated with calc-alkaline or alkaline subduction zone volcanics or granitoids of the I-type. Precambrian deposits range in age from 33l4±6 Ma to 561±9 Ma. The majority of the deposits fall into four age groupings with peaks around 3300±100Ma, 2700±100Ma, 1900±100 Ma. and 1100 ± 100 Ma which are indicative of major tectonic and magmatic episodes in different parts of the world. Precambrian deposits have many similarities with the younger porphyry copper deposits in the Phanerozoic. Some outstanding examples include Malanjkhand deposit (789 Mt x 0.83% Cu; 0.004% Mo: 0.2 gm/T Au; 6 gm/T Ag) and Tongkuangyu, China (380 Mt x 0.67% Cu) are in production. The Troilus Lake deposit, Quebec, Canada (42.9 Mt x 0.12% Cu; 1.4 gm/t Au; 1.4 gm/ t Ag) and Haib River, Namibia (600 Mt x 0.3% Cu) are being considered for exploitation.

After a review of the salient features of porphyry Cu±Mo±Au deposits in general and those of the Precambrian porphyry Cu±Mo±Au age in particular, it is suggested that Precambrian terrains should be good targets for exploration.