Geology of the Gibraltar Copper - Molybdenite Deposit , East - Central British Columbia ( 93 B / 9

During its 25 years of production from 1972 to 1998, the Gibraltar Cu-Mo mine in east-central British Columbia (Figure 1) milled a total of 324 million tons of ore containing an average 0.351% Cu from four open pits. Fieldwork during 2000 involved just over two weeks of detailed pit mapping at the mine. Results of this work and several earlier intervals of pit mapping conducted in 1998 and 1999 are summarized below. This detailed examination of the deposit followed an evaluation of its regional geological setting in 1998 (Ash et al., 1999a, b) which built on early work by Panteleyev (1977 and unpublished data). This paper documents controls copper and molybdenite mineralization at the Gibraltar mine. Detailed results of recently obtained isotopic ages for magmatism (U-Pb), mineralization (Re-Os), and alteration (Ar-Ar), as well as a detailed analysis of structural data will be presented elsewhere (Ash et al., in preparation).