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A polymetallic replacement deposit is an orebody of metallic minerals formed by the replacement of sedimentary, usually carbonate rock, by metal-bearing solutions in the vicinity of igneous intrusions.〔Hal T. Morris, 1986, "Polymetallic replacement deposits," in Dennis P. Cox and Donald A. Singer, ''Mineral Deposit Models'', US Geological Survey, Bulletin 1693, p.99-100.〕 When the ore forms a blanketlike body along the bedding plane of the rock, it is commonly called a manto ore deposit. Other ore geometries are chimneys and veins.〔Guilbert, John M. and Charles F. Park, Jr (1986) ''The Geology of Ore Deposits'', W. H. Freeman pp. 77-79 ISBN 0-7167-1456-6〕 Polymetallic replacements/mantos are often stratiform wall-rock replacement orebodies distal to porphyry copper deposits.〔(Sillitoe, Richard H. "Porphyry copper systems." Economic Geology 105.1 (2010): 3-41. )〕 The term ''manto'' is from the Spanish word for ''mantle'', or ''cloak'', although the geologic ''manto'' is more like a ''mantle roll'' than a sheetlike structure. Although similar in orebody geometry, host-rock lithology, and the presence of lead and zinc, carbonate hosted lead zinc ore deposits, also known as Mississippi Valley type, are considered a different type of ore deposits. Mississippi valley type ore deposits lack silver and gold mineralization, and are not associated with nearby igneous intrusions. ==Mineralogy== Polymetallic replacement deposits are significant sources of copper,〔Loader, S. E. "Supergene Enrichment of the Khanong Copper Resource, Sepon Project, Lao PDR." Pacrim'99 Congress: 10–13 October 1999, Bali, Indonesia. Australasian Institute of Mining and Metallurgy, 1999.〕 gold, silver, lead, manganese, and zinc. The metallic ore minerals are mostly in sulphides, such as galena, sphalerite, enargite, and argentite. Gangue minerals include quartz, pyrite, rhodochrosite, and barite. The mineralogy changes with distance from the intrusive rock. Closest to the intrusion is the copper-gold zone; next is the lead-silver zone, then the zinc-manganese zone.〔Hal T. Morris, 1986, "Polymetallic replacement deposits," in Dennis P. Cox and Donald A. Singer, ''Mineral Deposit Models'', US Geological Survey, Bulletin 1693, p.99-100.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Polymetallic replacement deposit」の詳細全文を読む スポンサード リンク
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