Imperial Metals talk at PDAC: March 09 at 4:30
Mineralization and hydrothermal characteristics of the Red Chris porphyry copper deposit, northern British Columbia, Canada.
Chris Rees, Imperial Metals Corporation
Steve Robertson, Imperial Metals Corporation
Imperial Metals’ Red Chris property is a porphyry copper-gold deposit, 80 kilometres south of Dease Lake in northern British Columbia. The project is at the advanced exploration stage, with an open-pit reserve of 276 million tonnes grading 0.349 % copper and 0.266 g/t gold, based on historic drilling to approximately 400 metres below surface. The ore body in the proven and probable category spans a 1500 m x 500 m area over the East Zone and Main Zone. While Imperial prepares for development of this shallow part of the deposit, a deep-drilling program initiated in 2007 discovered that high-grade mineralization in the East Zone continues for at least a further 600 metres vertically below the current pit design. Subsequent exploration has focussed on delineating the form and grade characteristics of the below-pit deposit and its potential for expanding the scope of the project.
Red Chris is in the accreted arc terrane of Stikinia in the Canadian Cordillera. It is hosted by the Red Stock, a Late Triassic plagioclase- hornblende -phyric monzodiorite, emplaced into Middle-Late Triassic Stuhini Group island-arc basaltic volcanic and sedimentary rocks. The stock is a suite of dikes with an elongate, ENE trend over 5 km and a width of at least 1.5 km. It is truncated to the south by down-faulted, post-mineralization Middle Jurassic sedimentary rocks. Mineralization is concentrated along the central axis of the stock, associated with multi-stage quartz veins carrying chalcopyrite and locally predominant bornite, which are also disseminated in the host monzodiorite. Moderate to intense sericite-quartz-pyrite (chlorite-ferrocarbonate-specular hematite) alteration is widespread in the stock, especially at the periphery and upper levels, and is an overprint on an earlier potassic (K-feldspar-biotite-magnetite) alteration stage, which is preserved in the core of the system in the mid- and lower levels of the East Zone, and to a lesser extent, deep in the Main Zone.
A deep hole drilled in 2007 in the East Zone intersected 1,024.1 metres grading 1.01% copper and 1.26 g/t gold. In 2009, a step-out hole 170 metres to the northeast intersected 647.5 metres of 1.50% copper and 2.68 g/t gold, including a particularly high-grade zone below the presently designed pit of 4.12% copper and 8.83 g/t gold over 152.5 metres. These and other results continue to indicate that Red Chris is a much larger and richer copper-gold system than had been assumed |
