The GSC Logan Club and Ottawa-Carleton Geosience Centre Seminar

The GSC Logan Club and Ottawa-Carleton Geoscience Centre welcomes Dr. Hamid Mumin, 2011-2012 CIM Distinguished Lecturer:


"Iron Oxide Copper-Gold Deposits in Genetic Context"

Monday December 5, 2011

Talk #1:  Carleton University, Herzberg Rm. 3120, 11:30AM-12:30PM.  Lunch to follow.

Talk #2:  GSC, 601 Booth St., Rm. 177, 2:30-3:30PM.



Hydrothermal iron oxide copper-gold (IOCG) deposits inspire controversy and debate over their classification, origin and, in particular, their relationship to a variety of disparate deposit groups. The IOCG deposit-type proper is comprised of a recognizable group of hydrothermal, primarily igneous-associated deposits with: i) greater than 15 to 20% hydrothermal magnetite and/or hematite genetically associated with economic mineralization; ii) economic accumulation of one or more of Fe, Cu, Au, U, Ag, Co, Bi, Mo ± a variety of other metals in minor or localized concentrations; and iii) spatially extensive and diagnostic hydrothermal systems characterized by a core zone of higher temperature alkali-iron (Na-K-Fe) alteration, and distal lower temperature K-Fe-Ca-Si alteration.

  A genetic and spatial association of IOCG systems to porphyry copper, iron oxide apatite, iron oxide copper-gold, skarn and epithermal deposit types is well manifested in the 1.9 to 1.8 Ga Great Bear Magmatic Zone (GBMZ) in the Northwest Territories, where superb preservation and bedrock exposure provide a measure of much needed clarity. Felsic to intermediate stratovolcano complexes are preserved intermittently along the GBMZ. Their subvolcanic intrusions generated giant IOCG fertile systems, which in some areas spatially exceed 100 square kilometres in exposed extent. Within the same hydrothermal systems are found a continuum of porphyry, IOCG and epithermal deposit styles that, in isolation and out of context, can be mistaken for disparate and unrelated events.

In modelling the IOCG deposits of the GBMZ, a pattern of alteration, mineralization and geotectonic setting emerges that is both distinctly different, yet clearly resembles some classic porphyry systems. Some of the underlying reasons for these similarities and differences are illustrated and discussed. Most importantly, placing IOCG systems in their global genetic context provides very attractive and robust models for exploration of igneous-hydrothermal systems.