This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1912 Excerpt: ... the upper zones tend to migrate downward. Thus the vein walls may show pyrite and chalcopyrite, and perhaps blende, associated with quartz, fluorite and garnet. Next will be a band of galena chiefly, and blende, with siderite, barite, and quartz; a third stage may be represented by gold, quartz, and calcite; and ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1912 Excerpt: ... the upper zones tend to migrate downward. Thus the vein walls may show pyrite and chalcopyrite, and perhaps blende, associated with quartz, fluorite and garnet. Next will be a band of galena chiefly, and blende, with siderite, barite, and quartz; a third stage may be represented by gold, quartz, and calcite; and finally there will be a barren calcite stage. These conditions might be represented diagramatically as shown in Fig. 60. The tendency is for the upper stages to work downward overlapping and cutting the earlier ones. This process would be reversed if the heat center were rising instead of sinking," as might be the case if an intrusive mass were slowly penetrating overlying strata. This is believed to have been the case at 33 Aspen, Colorado, where the normally earlier vein stages cut those which are usually characteristic of later periods. (Refer.: J. E. Spurr, Monograph 31, U. S. Geological Survey, and Economic Geology, Vol. IV, No. 1 1 4--"Ore Deposition at Aspen, Colorado.") 4. In this case the ore is argentiferous galena and gold quartz gangue chiefly; on the lower levels of the mine gold values are smaller and more scattered, there are galena pIG. 60. Diagram and blende, with some pyrite and chalcopy-matic illustration of rite. The inference is that the deposit is overlapping vein passing from the middle vein zones to the staSeslower zone and will probably be less valuable. 5. The richer ore is chiefly tetrahedrite, pyrargyrite, and polybasite; lower grade material is galena and blende, gangue is quartz, barite, and calcite. It is probable that the deposit is in the upper middle vein zone, and that with depth the rich sulphides will give way more and more to galena and blende or chalcopyrite and bornite. The various cases outlin...
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PLEASE NOTE, WE DO NOT SHIP TO DENMARK. New Book. Shipped from UK in 4 to 14 days. Established seller since 2000. Please note we cannot offer an expedited shipping service from the UK.
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PLEASE NOTE, WE DO NOT SHIP TO DENMARK. New Book. Shipped from UK in 4 to 14 days. Established seller since 2000. Please note we cannot offer an expedited shipping service from the UK.
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PLEASE NOTE, WE DO NOT SHIP TO DENMARK. New Book. Shipped from UK in 4 to 14 days. Established seller since 2000. Please note we cannot offer an expedited shipping service from the UK.
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Seller's Description:
PLEASE NOTE, WE DO NOT SHIP TO DENMARK. New Book. Shipped from UK in 4 to 14 days. Established seller since 2000. Please note we cannot offer an expedited shipping service from the UK.
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This is an ex-library book and may have the usual library/used-book markings inside. This book has hardback covers. In fair condition, suitable as a study copy. No dust jacket. Please note the Image in this listing is a stock photo and may not match the covers of the actual item, 450grams, ISBN:
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PLEASE NOTE, WE DO NOT SHIP TO DENMARK. New Book. Shipped from UK in 4 to 14 days. Established seller since 2000. Please note we cannot offer an expedited shipping service from the UK.
