| 交代岩与其有关铁矿形成的铁质来源的模拟实验 |
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| 引用本文：.1987.The Simulation Experiment On Iron Source In The Formation Of Metasomatites And Their Related Ore Deposits[J].Mineral Deposits,6(2):63~77 |
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| 中文摘要:本文采用我国各地不同交代类型的铁矿床的直接围岩——橄辉岩、辉绿岩、黑云母辉石闪长岩、石英闪长岩．凝灰质粉砂岩、晶屑玻屑凝灰岩、绢云母石英片岩、黑云母石英片岩和辉石角闪斜长麻粒岩作为实验原料，用化学试剂模拟配制了含H2O、F，Cl和CO2等挥发分的岩浆和岩浆期热液、火山气成热液、地下卤水和变质混合岩化热液作为反应溶液，它们在高温高压下的冷封自紧式带有黄金衬套的高压釜内相互进行作用。实验结果表明，在350-650℃的温度和(500-700)×105 Pa的压力下，不同成分的反应溶液从不同岩石中萃取出TF。的量为5.60-3881.59 mg/l，构成了含铁矿液。在高温高压下铁主要呈Fe2+形式存在，析出铁的量大都随着温度升高而增加，随着pH值增加而减少。由此可见，上升的成矿溶液不断地从含铁围者中萃取铁是交代岩及其铁矿形成的主要铁质来源之一。 |
| 中文关键词:交代岩 高温高压模拟实验 铁质来源 |
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| The Simulation Experiment On Iron Source In The Formation Of Metasomatites And Their Related Ore Deposits |
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| Abstract:This paper makes an attempt to investigate the problem of iron sources in the formation of metasomatites and their related iron deposits by experiment on the extraction of iron from the rocks. Samples were collected from country rocks of metasomatic iron deposits in various parts of China to be used as starting materials. They include natural and unaltered intrusive rocks (olivine - pyroxenite from Hongge, Sichuan. diabase from Makeng, Fujian, biotite-pyroxene diorite and quartz diorite from Daye, Hubei), volcanic-subvolcanic rocks and volcanic sedimentary rocks (andesite and tuffaceous siltstone from Huanggang, Inner Mongolia; ignimbrite from Yamansu, Xinjiang; subvolcanic diadase from Cihai, Xinjiang) and metamoiphic iocks (sericite-quautz scbist from Shilu, Guangdong; biotite-quartz schist from Mengjiagang, Heilongjiang; augite- amphibole- plagioclase granulite from Tianbaoshan, Heilongjiang ). According to the contents of such major volatiles as F, Cl, H2O and CO2 and taking into account the characteristics of potassium and sodium metasomatism that the rocks had undergone, the authors is used chemical agents to compound as aqueous media simulated magmatic and post-magmatic fluids, volcanic gas-fluids, underground hot brine as well as metamorphosed and migmatized fluids, which reacted upon each other under high temperature and pressure. The experimentation was performed in the Bridgman sealed pressure vessels with gold liners. A gold basket loaded with specimens was put in the working cavity of the pressure vessels filled with aqueous media, and then the pressure vessels were placed in the constant temperature field of the experimental furnace (SRJ); with the temperatures controlled by the automatic precise control (DWK-703) and measured by standard Le Chatelier thermocouples (LB-3). Temperatures for the experiment were 350-650℃, pressures (500-700)×105Pa, pH of the media 2.5-6.0, and duration of the experiment 120-144 hours. As soon as the lids of the quenched pressure vessels taken out to perform immediate quantitative tents. Some pbenomena can be observed from the experiment: (1) When aqueous media of different compositions are reacted with various sorts of rocks under 350-650℃ and (500-700)×105Pa, TFe 5.60-381.89mg/l is extracted to make up iron-bearing ore solutions. (2) Under constant pressure, when aqueous media of identical composition react upon the same sort of rock, the iron quantity extracted from the rock increases. with rising temperature, and this tendency becomes drastic when the temperature is above 450℃. (3) Under high temperature and pressure, the iron extracted from the rock mostly exists as ferrous iron in the solution, and is transported probably as complexes. (4) Under constant temperature and pressure, when aqueous media of different pH react upon the same sort of rock, the quantity of extracted iron increases with decreasing pH value of aqueous media. It is thus concluded that one of the main sources of iron during the formation of metasomatites and their related iron ore was the iron extracted from the wall rock by ore-forming solutions. |
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