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r <br />T-4518 <br />47 <br />Mineralization <br />The main purpose for studying the mineralization at the Cross deposit w;is to <br />determine the presence of a macroscopic mineral or mineral assemblage indicative of <br />microscopic gold. To this end, vein mineralogy and the paragenedc sequence were <br />determined through the study of 32 polished thin sections. Mineralization occurred in <br />seven stages distinguished on the basis of cross-cutting textural relationships an~i <br />fracturing. The stages of mineralization are: 1)fine-grained quartz-pytite+~tolybdenite <br />(Fig. 29a,b,fl; 2) medium- to coarse-grained quartz-pyrite±seticite±hemadte~phalerite_+ <br />galena (Fig. 29c,d,fl; 3) cazbonate stage calcite and dolomite (Fig. 29e}; 4} main base- and <br />precious-metal stage with sphalerite-galena-chalcopytite-electrum-acanthite (Fig. 29g); <br />and 5) sulfosalt stage with chalcopyrite-stromeyerite-tetrahedrite-tennantite-proustite- <br />pyrargyrite-famatittite; 6) dolomite (Fig. 29h); and 7) supergene stage covellite-chalcceite- <br />digenite-malachite-azurite-gold-silver-gcethite-lepidcerocite. The interpreted pazagenedc <br />sequence is shown in Figure 30 and a list of mineral formulae for species discussed is <br />given in Table 1. <br />Fine-Grained Ouartz-Pvrite Stage <br />Quartz and pyrite comprise the eazliest stage of mineralization which <br />macroscopically appears to be blue-gray, aphanidc quartz. The quartz is fine grained <br />(c500 µm) and anhedral while the pyrite isfine-grained (c500 µm) and anhedrrl to <br />euhedral (Fig. 31a). Molybdenite occurs less commonly with the fine-grained ~luartz. <br />