Cordilleran Vein Type Deposits Examples
Cordilleran Vein Type Deposits Examples
Cordilleran Vein Type Deposits Examples
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<strong>Vein</strong>s 11/3/10<br />
Ore deposits<br />
• Most in fractures and shears in Belt rocks<br />
– Minor structures more favorable than major<br />
• Some ore in monzonites, lamprophyres<br />
unmineralized<br />
• Briile rocks more highly mineralized<br />
• Galena, sphalerite, tetrahedrite,<br />
chalcopyrite, pyrrho>te, magne>te,<br />
arsenopyrite<br />
– Minor bornite, chalcocite, s>bnite, Cu-‐Sb-‐S<br />
sulfosalts, scheelite, uraninite<br />
Ores (cont)<br />
• Arsenopyrite forms envelopes around ore<br />
• Qtz, siderite, pyrite, (barite) as gangue<br />
– Typical ‘mesothermal’ assemblage<br />
• 10% combined Pb-‐Zn; 1 oz/tonne Ag<br />
• Ag in tetrahedrite, not galena<br />
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