SMEDG – Notice of Meeting

DATE: Thursday 27th July 2000 – 5.30pm for 6pm

VENUE: 1st Floor, Rugby Club, Rugby (Crane) Place, Sydney

SPEAKER: Ken Maiden – Pegmont Mines

TOPIC: “Exploring for Copper in the Western Mount Isa Block”While Mount Isa is by far the largest copper deposit in the western Mount Isa Block, ongoing exploration is demonstrating that the region has excellent potential for discovery of other copper deposits.The deposits are significantly different from the “classical” stratabound copper deposits of the European Kupferschiefer and the Central African Copperbelt. They resulted from a regional hydrothermal event focussed along faults during waning metamorphism. Metal concentrations were precipitated in dilational sites such as fault splays, intersections and “jogs”. Deposits may be either broadly stratabound or transgressive to stratigraphy and are associated with intense alteration and brecciation of the host rocks. The style of mineralisation varies from veins and stockworks to breccia fillings, disseminated zones and massive replacements. In detail, there is considerable variation in deposit geometry and mineralisation style resulting from different host rocks, different fault geometry, and different fluid movement history. From a commercial perspective, important features are (a) they have high copper grades, (b) they may have associated metals such as cobalt and gold, and (c) deep zones of leachable supergene ore are developed.Mineralised systems may be expressed by:· Zones of fracturing, brecciation and quartz-carbonate-sulphide veining· Alteration: silica-dolomite with pyrite, chlorite, Fe carbonate, hematite, muscovite· Siliceous gossan, gossanous breccia, quartz-carbonate-limonite veins, massive hematite· Geochemical anomalies· Electrical geophysical anomalies· Subtle gravity anomalies due to silica-dolomite alteration.BRIEF C.V. – KEN MAIDEN1968: BSc (Hons), UNSW1972: PhD, UNSW: Project: Deformation and metamorphism of the Broken Hill deposit1972-77: Geologist, CSR Limited: Stuart Shelf (Mount Gunson) and Bangka Island, Indonesia1977-79: Lecturer in Economic Geology, Canberra CAE1979-86: Senior Lecturer in Economic Geology, University of the Witwatersrand, Johannesburg.Research on stratabound and VHMS copper deposits in Namibia and Zimbabwe1987-89: Geological consultant, based in Sydney1990-95: Principal Geologist, MIM Exploration: Mainly in the Mount Isa Block1995-2000: Principal, Kraton Geoscience (geological consultant)1996-2000: Director, Kalahari Mining NL: Copper projects in Namibia and Botswana

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