The ore deposits of Utah . bonate monheimite. The relative pro-portion of the metals in the mineral is probablydependent on their relative concentration inthe solution. The carbonate thus formed maysubsequently alter to limonite, calamine, hy-drozincite, aurichalcite, and probably otherminerals. If the solutions in their downward journeydo not encounter limestone but traversequartzite or other siliceous materials themetials show little tendency to precipitate andare probably either carried away in solutionor are so dispersed before precipitation that 1 Knopf, Adolph, Mineral resources of the I
The ore deposits of Utah . bonate monheimite. The relative pro-portion of the metals in the mineral is probablydependent on their relative concentration inthe solution. The carbonate thus formed maysubsequently alter to limonite, calamine, hy-drozincite, aurichalcite, and probably otherminerals. If the solutions in their downward journeydo not encounter limestone but traversequartzite or other siliceous materials themetials show little tendency to precipitate andare probably either carried away in solutionor are so dispersed before precipitation that 1 Knopf, Adolph, Mineral resources of the Inyo and White mountains,Cal.: U. S. Geol. Survey Bull. 540, p. 106, 1914. 212 ORE DEPOSITS OF UTAH. they do iu)t form deposits of economic impor-tance. Under favorable conditions the solutionsmight travel for some distance through sili-ceous beds without being dispersed and oncoming in contact with limestone might formcommercial deposits. The most favorable conditions, then, forthe formation of oxidized zinc ores are where. Figure 34.—Diagram showing a condition favorable to the formationof oxidized zinc deposits. the primary ores are underlain by limestonesor dolomites which are free from insolubleimpurities, and into wliich the downward-moving solutions from the oxidizing sulphidesmay pass. (See fig. 34.) The purity of the lime-stone probably has an important effect on thevalue of the deposits, both because any sili-ceous impurities would doubtless remain in thecarbonate ore and thus reduce its value, andbecause the precipitating effect of impurelimestones is probably much less than that ofthe relatively pure limestone, as it apparentlyis in primary deposits (p. 174). Under the most favorable conditions impor-tant secondary zinc deposits may form fromprimary deposits containing only a smallpercentage of zinc. Thus Knopfs has shownthat in the Cerro Gordo mine large bodies ofoxidized zinc ores have been formed by thealteration of sulphide bodies containing only1 to 2 per cent
Size: 2003px × 1248px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectminesandmineralresou
