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The Role Of Falcon® Agg In The Mumbwa, Zambia, Iron Oxide Copper-gold Discovery
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 13th SAGA Biennial Conference & Exhibition, Oct 2013, cp-378-00043
Abstract
The Mumbwa iron oxide copper-gold (IOCG) exploration project is located in west-central Zambia. A FALCON® airborne gravity gradiometer (AGG) survey, flown by Fugro Airborne Surveys in 2004, was the catalyst to advance IOCG exploration efforts in the Mumbwa area, leading to the Kitumba discovery. The FALCON AGG survey mapped several regional elements considered prerequisite for prospective IOCG terrains: post-tectonic igneous intrusions and intersection of district-scale fault structures, thus highlighting two prospects, Kitumba and Mutoya, as particularly amenable to IOCG mineralization. The FALCON AGG survey accurately delineated the spatial extents of the Kitumba and Mutoya prospects and identified significant uranium anomalism, upon which the Kitumba discovery hole S36-001 was sited. In 2007 AIM Resources (now Blackthorn Resources), in a joint venture with BHP Billiton, drilled the Kitumba discovery hole, S36-001, intersecting significant Cu mineralisation over a 655 m interval grading 0.46% Cu. In-fill drilling in 2011 intersected high-grade mineralisation in several drill holes, including drill hole S36-038 with the best drilled thickness intersections containing 223m at 4.67% Cu. In 2012, Blackthorn Resources reported the total JORC Inferred and Indicated Mineral Resource of the Kitumba prospect as 187Mt of 1.14% Cu and 0.04 g/t Au, using a 0.5% Cu cut off. The FALCON AGG survey also identified an 19km N-S striking, hitherto unknown, massive hematite-siderite IOCG system, Mushingashi, under 250m-350m sedimentary cover. Widely spaced reconnaissance drilling has intersected low tenor Cu anomalism in hematite-siderite breccia systems with large areas remaining untested. The understanding of the mineralization in the Mumbwa area remains patchy. This is primarily due to the sheer size of the IOCG footprints of the Kitumba, Mutoya and Mushingashi systems, but also due to extensive leaching and possible supergene processes at Kitumba. Ground based geophysics (3D IP/MT) and additional drilling has been undertaken at Kitumba and at the new FALCON AGG prospect, Kakozhi, to the west of Mutoya, to address this issue.