中国地质大学长城学院
本科毕业论文外文资料翻译
系 别： 地球科学与资源系
专 业： 资源勘查工程
姓 名：
学 号：
2014年04月15日
外文资料翻译译文
风化矿床
摘 要：地壳表层岩石或矿石经风化作用而形成的矿床。风化作用大多发生在潜水面附近或其上，因此，风化矿床的深度一般距地面不超过数十米，特殊情况下达 100～200米,个别可达1500～2000米。风化矿床规模以中小型为主，个别大型或超大型矿床面积达数千平方公里，储量几亿吨甚至超过 100亿吨。矿石疏松，便于开采加工。风化矿床中最多的是铁矿和铝土矿，其次是镍、锰、铀、铜、稀土元素、粘土、磷灰石、菱锰矿。其中镍矿床和铝土矿床在世界镍和铝的生产中占有重要地位，其他矿种也对产地经济有重要影响。
关键词：风化；矿床；残余；淋积
1 影响风化成矿作用的因素
主要有以下几方面：
①原岩成分。风化的原岩是成矿物质来源。基性和超基性岩中铁、镍的含量既高,又易于风化,有利于形成铁、镍的风化矿床。又如长石质岩石风化后可形成各种粘土或铝土矿床。
②气候条件。它对风化成矿作用有决定性影响。高温有利于原岩的分解和其中碱和碱土金属的带出，气候潮湿雨量充沛也有利于风化作用，因此在热带亚热带地区最有利于风化矿床的形成。
③地形因素。山区地形高差大，风化产物不易保留；强烈夷平地形，也不利于风化成矿作用持续进行；介于二者之间的中低山脉和丘陵地带最有利于风化矿床的发育。
④潜水面。在潜水面以上，强烈的化学中和淋滤作用使残留物质富集成矿，而其下则可能产生淋滤物质的富集。因此潜水面的深度适中，岩石的分解和淋失相适应，有利于风化矿床的形成。
⑤地质构造。规模大的裂隙带和破碎带，决定了风化矿床的位置和延伸方向，同时也控制了风化矿床的深度。构造运动还影响风化矿床的保存条件，在构造上隆地区风化矿床易受剥蚀破坏，在沉降地区风化矿床则被掩埋，只有在微弱沉降的情况下，风化矿床才能被覆盖而保存起来。
⑥时间因素。形成规模和质量都好的风化矿床，需要很长的时间。已知的风化矿床，多数是在第三纪、第四纪或中生代形成的。由于世界各地地壳发育历史不完全一致,它们的风化矿床形成时间也不相同,但它们都是在历次地壳运动后期，在稳定的地台上形成的。
2矿床类型
风化矿床按矿床的形态可以分为沿地表发育的面型矿床，沿岩石破碎带发育的线型矿床和沿两种岩石的接触面发育的接触型矿床。按风化剖面的分带性及其形成机理可以分为风化壳顶部的残积砂矿床、潜水面上的残余矿床及潜水面以下的淋积矿床。因为残积砂矿是物理风化产物，其成矿规律和矿床特点与其他成因的砂矿床（见沉积矿床）类似，因而也可归为砂矿床。
3残余矿床
地表岩石经化学风化和生物风化作用后，一部分物质被淋滤，而另一部分残留在风化壳中富集而成的矿床，也称残留矿床。风化残余物质都是在地表条件下稳定的物质，其中铁和铝是最稳定的，风化后成为铁矿和铝土矿而富集在风化壳上部成矿。二氧化硅、磷、锰、钴、镍、铜、铀、钒稳定性稍差，在其他条件有利时，可以形成氧化物、磷酸盐及其他稳定的含氧盐类而成为残余矿床。重要的残余矿床有下列几种：
①红土型铁矿床。超基性岩在炎热潮湿地区经过强烈风化淋滤作用，岩石中的镁和硅被地下水带走，低价铁大部分变为高价铁，形成难溶的含水高铁氧化物，然后脱水成赤铁矿。其结果形成了红土型风化壳，其上部含铁高达50％以上成为富铁矿。矿体内常有原岩中残留的富含铬、钛、钒矿物或风化后残留的钴、镍、锰矿物，可以直接冶炼成优质合金钢。著名的西澳哈默斯利富铁矿,矿石达244.8亿吨，古巴卡腊贾斯铁矿的天然合金钢富矿石也达到178亿吨，此外,在印尼、菲律宾、前苏联、美国也都有分布。这类矿床在中国不甚发育，但华北的山西式铁矿，至少有一部分是含铁碳酸盐岩石风化产物。
②红土型铝土矿矿床。发育在热带和亚热带地区的碱性岩和基性岩风化壳中。这里经强烈风化作用分离出来的碱和碱土金属离子，使水呈碱性，能溶解并带出二氧化硅，而在风化壳中残留的铝形成了三水铝石和一水铝石，与铁的氧化物和粘土共生，成为易采易炼的优质铝矿石，是铝的重要来源。美国阿肯色及印度中央高原和巴西、几内亚等地都有这类矿床。另一种铝土矿床则主要是石灰岩风化产物，称为钙红土型铝土矿，是含铝石灰岩风化后形成了铁的氧化物和粘土，被带到岩溶洼地中经改造而成铝土矿；有的可能是附近的红土风化产物，被流水搬运到石灰岩溶洞中的，所以也称为喀斯特型铝土矿床。这种矿床多分布在地中海沿岸国家和印度、前苏联等地。中国广西平果铝土矿是二叠系中的原生铝土矿经风化崩塌堆积而成。
③红土型镍矿床。又称硅酸盐镍矿床，由超基性岩风化而成。产在第三纪、第四纪或中生带的热带、亚热带蛇纹岩风化壳中。当超基性岩风化时，以类质同象混入橄榄石和辉石中的镍转入蛇纹石中，以后蛇纹石又经分解,镍即析出来,进入溶液,从风化壳上部迁到下部,以次生镍矿物和含镍矿物再沉淀下来而形成工业富集。著名的南太平洋新喀里多尼亚（法属）硅酸镍矿床，规模很大。中国的云南、台湾等地也有这类矿床。
④残余粘土矿床。岩石中富铝硅酸盐矿物在潮湿温暖气候条件下风化,而形成粘土矿物为主的堆积,根据原岩成分和风化程度而形成高岭土矿床或膨润土矿床。高岭土以高岭石为主要成分，是酸性和碱性硅酸盐岩石风化过程中，尚未达到游离氧化铝阶段，形成了硅酸盐矿物，而酸性介质淋滤了铁而形成的。中国开采高岭土矿床的历史悠久，以在长江下游几省为主，高岭土矿是云母花岗岩和花岗伟晶岩的风化产物。膨润土以微晶高岭石为主,是中酸性火山岩风化形成的。中国东部侏罗-白垩纪火山岩中膨润土分布较广，其中一部分是风化形成的。如吉林九台膨润土矿床中主要产出的钙质膨润土是风化残余矿床，而钠质膨润土则是火山喷发间歇期，在湖水中沉积的。
⑤残余稀土元素矿床。酸性岩浆岩中分散存在的稀土矿物当岩石风化时被释放出来，以离子状态被粘土矿物吸附，而在风化壳中富集成矿，也称离子吸附型稀土元素矿床。中国南岭地区有花岗岩风化残余的重稀土元素矿床（钇族为主）。华东的流纹斑岩中含轻稀土元素（铈族）较多，在岩石风化时可富集成矿。
4淋积矿床
指原岩中活动性较大的物质，经过风化淋滤被地下水带至邻近的岩石中富集形成的矿床。这种矿床的形成除由成矿元素的地球化学性质决定外，还需要有明显的地球化学屏障，主要是潜水运动的阻滞和物理化学环境的急剧改变。淋积铀矿、铜矿是常见的淋积矿床。
①淋积铀矿床。原岩风化时，其中分散存在的铀化合物被带出到有利地段沉积富集成矿。铀是变价元素，当含铀矿物中4价铀氧化成为6价铀,就易于淋滤带去,在运移途中遇到铀的沉淀剂，它就转入沉积物中富集起来。这种铀矿床的时空分布很广，又可分为砂砾岩中的铀矿床和煤或沥青质岩石中的铀矿床两类。前者以美国科罗拉多高原的铀钒矿床最著名，后者则是由于煤和沥青是还原剂，促进了潜水中的铀化合物沉淀富集而成矿的。
②淋积铜矿。经常位于红层中，分布较广泛，铜常与铀共生，也有单独成矿的。该种矿床成因复杂，有同生沉积说和淋滤再沉积说。淋积成的铜矿石由铜的氧化物和含氧盐（碳酸盐等）组成，是分散存在的原生硫化物经氧化、迁移，在潜水面附近堆积成的。
外文原文
Weathering mineral deposit
ABSTRACT
Rock or mineral surface weathering crust and formation of ore deposits.Weathering occurs mostly near the phreatic surface or on it, therefore, the depth of the weathering deposits generally no more than dozens of meters from ground, special cases from 100 to 200 meters, the individual can reach 1500 ~ 2000 meters.Weathered ore deposit scale is given priority to with small and medium, large or superlarge individual area of thousands of square kilometers, reserves of hundreds of millions of tons of even more than 10 billion tons.Ore loose, facilitate mining processing.Weathered ore deposit is the most in iron ore and bauxite, followed by nickel, manganese, uranium, copper and rare earth elements, clay, apatite, rhodochrosite.The nickel deposit and bauxite deposit in the world occupies an important position, in the production of nickel and aluminum, the other minerals also have important effects on producing area economy.
Key words：Weathering; Deposit; Residual; Illuviation
1 Factors affecting weathering mineralization
Basically has the following several aspects
(1) The original rock composition. Weathering of original rock is the source of ore-forming materials. Basic and ultrabasic rock with high content of Fe, Ni, and easy to weathering, and beneficial to form the weathering of iron, nickel deposit. And like a feldspathic rock weathering can form various kinds of clay or bauxite deposit.
(2) The weather conditions. It has a decisive effect on weathering mineralization. High temperature is beneficial to the decomposition of the original rock and brought out one of the alkali and alkaline earth metal, damp climate rainfall amount and conducive to weathering, therefore the most favorable for the formation of weathering deposits in tropical and subtropical region.
(3) The terrain factors. Mountainous terrain elevation difference is big, weathering products is not easy to keep; Strongly flattened terrain, also go against weathering mineralization continuous; Between the low mountains and hills area the most beneficial to the growth of weathered ore deposit.
(4) The phreatic surface. Above the phreatic surface, strong chemical and leaching effect made residual material enrichment, and below it may produce leaching material enrichment. So the diving depth is moderate, the decomposition of the rock and leaching, favorable for the formation of weathered ore deposit.
(5) Geological structure. Big fissure zone and fracture zone, and determine the position of weathering deposits and extending direction, but also control the depth of weathering deposits. Tectonic movement also affect the preservation conditions of weathering deposits, weathering deposits on the structural lung area vulnerable to erosion, weathering deposits are buried in subsidence area, only in the case of small settlement, weathering deposits can be covered and preserved.
(6) Time factor.Good weathering deposits both scale and quality, take a long time.Known weathering deposits, mostly in the tertiary, quaternary or Mesozoic formation.History of the earth's crust development around the world are not completely consistent, their weathering deposits forming time is different, but they are late in all previous crustal movement, formed in a stable platform.
2 Types of ore deposits
Weathering deposits according to the morphology of ore deposit can be divided into deposit along the surface of the earth's surface development type, linear deposits along the rock broken zone and along the contact surfaces of the two kinds of rock contact type deposit.Zoning by weathering profile and its forming mechanism can be divided into the top of the crust of weathering eluvial placer deposit, diving residual ore deposit and dive below the surface on the surface of the deposit.Because the eluvial placer is physical weathering products, and its characteristics and other metallogenic regularity and causes of the placer deposit (see sedimentary deposit), and therefore can be classified as placer deposit.
3 The residual deposit
Surface after chemical weathering and biological weathering rock, part of the material was leached, and the other part of the residual accumulation in the weathering crust of deposits, also known as residual ore deposit.Weathering residual substance is stable under the condition of the surface of the earth, including iron and aluminum is the most stable, after weathering as iron ore and bauxite in the upper crust of weathering mineralization and enrichment.Silica, phosphorus, manganese and cobalt, nickel, copper, uranium, vanadium is a bit poor stability, in other conditions favorable, can form oxides, phosphate and other stable oxygen salts as residual ore deposit.
Has the following several important residual ore deposit
(1) Red clay type iron ore deposit.Ultrabasic rock in hot, humid area after a strong weathering leaching effect, magnesium and silicon are groundwater away from the rock, most low iron into high iron, high water cut of formation of refractory iron oxide, and then dehydration into hematite.The results form the laterite weathering crust, the upper iron up to more than 50% to become rich iron ore.Within the ore body is the original rock residue rich in chromium, titanium, vanadium mineral or after weathering residues of cobalt, nickel, manganese ore, can direct smelting into high quality alloy steel.Famous western Australia hammer, rich iron ore, ore 24.48 billion tons, Cuba card la just natural alloy rich ore of iron ore 17.8 billion tons, in addition, in Indonesia, the Philippines, the former Soviet union, the United States also have distribution.Less development of this type of ore deposits in China, but in north China's shanxi type iron ore, at least in part, is a product of iron carbonate rock weathering.
(2) The red clay type bauxite deposits.Growth in tropical and subtropical regions of alkaline rock and rock weathering crust.Here by separate strong weathering of alkali and alkaline earth metal ions, make alkaline water, can dissolve and out of the silicon dioxide, and residual aluminum in the weathering crust formed sanshui LvShi and LvShi monohydrate, symbiosis with iron oxide and clay, be easy in refining of high quality aluminum ore, is an important source of aluminum.And Arkansas in the United States and Brazil, guinea, India's central plateau has this type of ore deposits.Another type of bauxite deposit is mainly limestone weathering products, known as terra rossa type bauxite, are formed after LvShi limestone weathering iron oxide and clay, measures were taken to karst depressions with a bauxite;Some may be near laterite weathering products, handling by running water in to the limestone cave, so also known as karst type bauxite deposits.This ore deposit distribution in Mediterranean countries and India, the former Soviet union and other places.China's guangxi pingguo bauxite is primary bauxite by the weathering of the Permian collapsing.
(3) Type laterite nickel ore deposit.Also called silicate mineral deposit, composed of ultrabasic rock weathering.Production in the tertiary, quaternary or living with tropical and subtropical serpentinite weathering crust.When the ultrabasic rock weathering, with such quality as mixed with nickel in olivine and pyroxene into the serpentine, serpentine again after the decomposition, nickel analysis, namely into the solution, from top to bottom weathering crust, with secondary nickel minerals and enrichment of nickel minerals to settle and form industrial.Famous new caledonia in the south Pacific (French) silicate nickel deposit, big.China's yunnan and Taiwan also have this type of ore deposits.
(4) Residual clay deposits.Rock zhongfu aluminum silicate minerals in warm humid climate conditions of weathering, and form the accumulation of clay mineral is given priority to, according to the original rock composition and weathering degree and formation kaolin ore deposit or bentonite deposit.Kaolin with montmorillonite as the main ingredient, it is in the process of acidic and alkaline silicate rock weathering, has yet to reach the free alumina phase, formed the silicate minerals, and medium acidic leaching the iron.China mining kaolin ore deposit has a long history, mainly in the Yangtze river downstream of a few provinces, kaolin ore is mica granite and granite pegmatite weathering products.Bentonite is given priority to with montmorillonite, is formed by intermediate-acid volcanic rock weathering.Jurassic and cretaceous volcanic rocks in eastern China has a wide distribution of bentonite, part is formed by weathering.Such as jilin 9 bentonite deposits in the main output of calcium bentonite is weathering residual ore deposit, and the sodium bentonite is volcanic eruption intermittent period, deposited in the lake.
(5) Residual rare earth elements deposits.Acidic magmatic rocks in the dispersion of rare earth minerals are released when the rock weathering, in ionic form by clay mineral adsorption, and the enrichment of mineralization in the weathering crust, also known as the ion adsorption type rare earths mineral deposits.China nanling region have granite weathering residual heavy rare earth elements deposits (yttrium).East China's rhyolitic porphyry contains light rare earth element is more, when rock weathering enrichment.
4 Deposit formed by superficial leaching
Refers to the original rock of active substances, after weathering leaching was taken to a nearby groundwater enrichment of the rock formation of the deposit.The formation of this deposit not only decided by the geochemical nature of ore-forming elements, also need to have clear geochemical barrier, mainly is the diving movement of the block and the physical and chemical environment of rapid change.Spray deposition of the uranium ore, copper is a common deposit.
(1) Illuviation uranium deposits.The original rock weathering, the dispersion of uranium compounds was taken out to the favorable sedimentary enrichment.Uranium is a base element, when containing 4 price of uranium in uranium ore become 6 price of uranium oxide, it is easy to be leaching bring, met with the precipitation of uranium in migration agent, it turns into the sediments of enrichment.The uranium deposits of time and space distribution is very wide, can divide again glutenite of uranium deposits and coal, or bituminous rock uranium deposits in the two classes.The former Colorado plateau of vanadium uranium deposit in the United States, the most famous is the reductant, and the latter is due to the coal asphalt promoted the diving in the concentration and mineralization of uranium compounds.
(2) Copper deposition.Often in the red layer, are widely distributed, copper and uranium symbiosis, often also has a separate mineralization.Complex causes, this kind of deposit with syngenetic sedimentary and leaching deposit again.Pour into the copper ore of copper oxide and oxygen salt (carbonate, etc.), is dispersed native sulfur after oxidation, migration, accumulation of near the phreatic surface.
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