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Geology, Geochemistry And Genesis Of Mengku Iron Deposit In Fuyun Country, Xinjiang Province

Posted on:2008-06-27Degree:MasterType:Thesis
Country:ChinaCandidate:L G XuFull Text:PDF
GTID:2120360212483489Subject:Mineralogy, petrology, ore deposits
Abstract/Summary:PDF Full Text Request
Altay orogenic belt is one of the most important components of central Asia, which is a non-ferrous belt that rich in copper, iron, zinc-lead, nickel, gold and REE. Mengku iron deposit lies in the South of Altay orogenic belt which is the largest iron deposit in Xinjiang Province and is the typical one of this kind of deposit. Ore bodies are hosted in schist, amphibole- metadolerite, marble and plagioamphibloe metadolerite (primary rock is volcanic rock). Because only a little pluton is found in mining area and skarn is developed in wall rocks, the genesis of the deposit is quite controversial. This thesis based on detail field study of Mengku iron deposit, using some feasible methods such as EPMA, fluid inclusion homotemperature measuring and stable isotope measuring, recognize its petrology, mineralogy and geochemistry characteristics, and then give a reasonable explanation about its genesis. Some study results are as follows:1) Mengku iron deposit is hosted by metamorphic volcanic rocks, which primary rock is intermediate to basic mafic volcanic rock, volcanic tuff and some marine facies carbonate.2) The analytical results of electron microprobe show that the clinopyroxene are mainly diopside, with minor augite in skarn. The end member of garnet is dominated by andradite, with minor grossular and spessartine and the amphiboles of Mengku iron deposit are actinolite that belongs to ferro-edenite. Although skarn in Mengku iron deposit may formed because hydrothermal interacting with metamorphic volcanic rock, the characteristics of skarn minerals such as evolution process and geochemical component are similar with normal skarn.3) Stable isotope geochemistry and fluid inclusion characteristics indicate that the composition of sulfur isotope is similar with meteorolite, and meteoritic water played an important role after the late stage of ore forming.4) Subduction may cause amount of intermediate to basic volcanic rock intruded during late Paleozoic at the arc basin of active margins. Late stage hydrothermal interacted with primary volcanic rocks in high Eh, Temperature and suitable pressure surroundings, and magnetite formed in this period.
Keywords/Search Tags:skarn, EPMA, fluid inclusion, isotope geochemistry, ore forming mechanism, Mengku, Altay, Xinjiang
PDF Full Text Request
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