The veins are of variable size (up to 2 m thick), variable orientation, and occur in dilatant zones throughout the camp. Pegmatite-Type Veins: coarse-grained potassium feldspar, biotite, epidote, and calcite (±albite, apatite, garnet, and quartz) these veins are distinctive and occur with or without sulphide minerals. These veins are not abundant in the Pit 3 area, but are significant in Pit 2 and comprise much of the ore within areas north of Pit 2 and east of Ingerbelle. Magnetite Veins: with or without copper sulphide minerals, of variable size from fine fracture filling, to vein stockworks, to sheeted vein swarms, to 3-m to 4-m thick veins. Numerous veins, vein envelopes, and fracture-filling mineral assemblages crosscut, or occur within both potassic, and to a lesser extent, albitic alteration, and are described below. Potassic alteration appears to be spatially associated with certain phases (LH2) of the LHIC. Potassium alteration typically produces rocks with a faint to strong orange or pink colour, which is enhanced with weathering, suggesting that the alteration contains an ultra-fine dusting of hematite. In areas peripheral to the sodic alteration, potassic alteration is pervasive, either flooding the rock matrix with fine-grained potassium feldspar or replacing primary plagioclase with potassium feldspar, and ferro-magnesium minerals with biotite, epidote, calcite, chlorite, and magnetite. Where potassic alteration overprints the sodic alteration, it is almost exclusively as fracture fill and veins. Potassic alteration occurs as veins and fracture fill (K-feldspar and biotite), or as pervasive K-feldspar flooding of the rock matrix. Much of the sodic alteration appears to be early and pre-mineralization however, there also appears to be a more confined, later phase of sodic alteration with a high pyrite-tochalcopyrite ratio that occurs on the northern and southeastern sides of Pit 1, which may be associated with small cylindrical intrusions. A wide band of intense sodic- metasomatism cuts across the mine area in a northwest–southeast direction, extending from the north side of the Ingerbelle deposit and across the Similkameen River canyon, through the south side of Pit 2 and the north sides of Pit 1 and Pit 3. This process results in bleaching of the original rock and a reduction in grain size, forming a pale-gray or greenish-gray, very competent rock. In addition to albitization of feldspars and conversion of ferro-magnesium minerals to epidote (± diopside and chlorite), magnetite and opaque minerals are destroyed. Pervasive sodic alteration occurs as a texturally destructive albite-diopsideepidote metasomatism. Sodic alteration is commonly pervasive (sodic metasomatism), but can also occur as fracture- controlled veins or vein-stockworks. Three main types of alteration have been defined-hornfels, sodic, and potassic each has its own spatial and temporal distribution. Each mineralization type can be found in all pit areas, but each pit is unique with respect to the relative quantities and character of mineralization type.īoth mineralization and alteration demonstrate a zonation through the camp, though not in a manner typically associated with calc-alkaline porphyry deposits. Mineralization had been subdivided into four types, as follows: 1) disseminated and stockwork chalcopyrite, bornite, chalcocite, and pyrite in altered Nicola and LHIC rocks 2) hematite-magnetite-chalcopyrite replacements and/or veins 3) bornite-chalcopyrite associated with pegmatite-like veins (coarse masses of orthoclase, calcite, and biotite) and 4) chalcopyrite-bearing magnetite breccias. Although there are several areas that have been mined separately over time, both alteration and lower-grade mineralization occurs between these areas, and all mineralization is thought to be part of a large, single system.Īs a generalization, mineralization at Copper Mountain consists of structurally controlled, multidirectional veins and vein stockworks, with peripheral disseminations. Mineralization at Copper Mountain is classified as an alkalic porphyry deposit.
0 kommentar(er)
