共查询到20条相似文献，搜索用时 31 毫秒
1.
Peng Gu 《中国地球化学学报》1984,3(4):355-363
The most productive chromite ore deposits are formed through crystallization of chromite-ore magmas under definite physico-chemical conditions. The formation of chromite ore is controlled mainly by the degree of differentiation of ultrabasic magma. How to measure the degree of ultrabasic magmatic differentiation is key to understanding the mechanism of formation of chromite ore. Many geologists base their understanding of ultrabasic magmatic differentiation on whether there are obvious petrographical-facies zones in ultrabasic rocks. This viewpoint needs further discussing because most ultrabasic rock bodies showing petrographical zonation contain no mineral deposits. On the contrary mineral deposits may occur in the ultrabasic rocks without obvious petrographical zonation. Therefore, the author suggests to use the chemical characteristics of minerals to determine the degree of ultrabasic magmatic differentiation as a guide to search for chromite ore deposits. 相似文献
2.
巴西典型祖母绿矿床介绍 总被引：2，自引：1，他引：2
巴西的祖母绿矿床主要属于所谓的片岩型祖母绿矿床。它们产于富含暗色岩和伟晶岩的古老地盾区内。与矿化有关的伟晶岩往往脉幅小，分异不完全。最有利于矿化的围岩是富镁的滑石片岩，含滑石片岩，含滑石大理岩和黑云母片岩等。 相似文献
3.
中国软玉矿床类型及其矿物学特征 总被引：4，自引：0，他引：4
文章将中国11个产地的软玉（透闪石玉）矿床分为岩浆热液型和变质热液型两大类。其中岩浆热液型又根据侵入体的性质分为中酸性岩型、基性岩型、超基性岩型;变质热液型根据母岩特点分为碳酸盐岩型和蛇纹岩型,并从围岩和侵入岩体特征、矿体产状及大地构造背景等方面,对比分析了软玉矿床的相似性和差异性,总结了各产地软玉的品种、矿物成分、结构构造等矿物学特征;简单分析了软玉的找矿远景。 相似文献
4.
铬铁矿的找矿和研究工作有三个相互联系的环节,即在有利构造部位寻找超基性岩带(蛇绿岩带),圈定其中的超镁铁岩体;评价岩带和岩体的含铬性,选择铬铁矿找矿靶区;在含矿岩体中普查勘探工业铬铁矿矿床.我国近三十年来的铬矿找矿工作,对解决第1、3环节问题,已在实践和方法上积累了丰富经验:关键是如何从大量岩带(体)中判别具有成矿远景的岩带(体),建立起—套简易而有效的评价超基性岩含铬性的准则. 相似文献
5.
甘肃金川硫化铜镍矿床地质特征 总被引：11，自引：0，他引：11
金川矿床是我国知名的硫化铜镍矿床。它由四个矿区组成(图1)。该矿床除含有丰富的镍、铜外,还含有一些贵金属及钴等,为一含多种金属元素的硫化物矿床。本文是笔者在对该区多年积累的大量地质资料进行分析研究的基础上写成的,谬误之处,敬请指正。一、区域地质背景矿床位于阿拉善台块南西边缘,龙首山隆起东段北东侧深断裂的上盘(即南西侧)。龙首山基底为前长城系,盖层为长城—蓟县系和震旦系。前长城系内的八个伟晶花岗岩之云母样的同位素年龄为16.57—17.41亿年,一个片麻状花岗岩之白云母样的同位素年龄为17.86亿年。故这套深变质岩系的年龄应不小于18亿年。 相似文献
6.
中国铂族元素矿床类型和地质特征 总被引：18，自引：2，他引：18
根据成矿地质环境、容矿岩石类型、元素共生组合、矿床地质特征和成矿作用性质，将我国的铂族元素矿床划分为岩浆型、热液弄才外生型三大类型和九个亚类，而赋存于基性超基性岩体中的铜镍型铂族元素矿床是我国最重要的铂族元素矿床。 相似文献
7.
江西银山矿田伴生金银综合回收利用研究 总被引：2，自引：0，他引：2
叙述了银山铜铅锌多金属矿田铅锌成矿系列和铜硫成矿系列６个成矿带中伴生金银的赋存状态、富集特征和成矿规律，并进行伴生金银相关性分析。认为伴生金银是以独立矿物存在为主，主要载体矿物有黄铜矿，含砷铜矿物、黄铁矿、方铅矿和闪锌矿。Ａｕ、Ａｇ与Ｐｂ、Ｚｎ、Ｃｕ、Ｓ密切相关。同时分析了金银生产中存在的具体问题，提出综合回收金银的措施和建议。 相似文献
8.
Parkerite and bismutohauchecornite in chromitites of the Urals: Example of the Uralian Emerald Mines
An unusual ore mineralization represented by parkerite, millerite, bismutohauchecornite, bismuthinite, and nickeline was registered in altered chromitite from the Mariinsk emerald–beryllium deposit. Such mineralization is typical of Cu–Ni sulfide ores and hydrothermal veins from the five-element formation. This mineral assemblage was not registered in ophiolitic ultrabasic rocks and related chromitites. The find of bismutohauchecornite is the first in the Urals; the find of parkerite is the third. 相似文献
9.
Most of the sulfide nickel deposits in China occur on the margins of platforms and their outer mobilebelts. The ore-bearing basic-ultrabasic rock bodies were formed in the Proterozoic and Variscan. The types ofmetallogenic rock bodies include ultrahasic-basic complexes related to volcanism in eugeosynclines andultrabasic rock bodies, ultrabasic-basic complexes and basic rock bodies related to deep fractures. On the basisof ore-forming processes and modes, nickel sulfide deposits of China may be divided into two major types:in-situ magmatic liquid unmixing deposits and deep-seated magmatic liquid unmixing injection deposits. Thelatter may by subdivided into four types: single injection deposits, multiple injection deposits, and pulsatory in-jection depositis, and late injection deposits which may inject into either comagmatic rocks or other kinds ofcountry rocks. Two metallogenic models for nickel sulfide deposits are proposed in this paper. 相似文献
10.
朱赖民 《中国地球化学学报》1998,17(4):362-371
The relations between ultrabasic rocks and gold deposits in time,space and genesis are discussed in this paper,the research results show that the ore-forming materials of the gold deposits is characteristic of crust-mantle mixing,The formation of the gold deposits is related with the activity of juvenile fluids along with the intrusion of ultrabasic dikes.The ascending juvenile fluids not only offered part of the gold.water and mineralizers for gold mineralization but also promoted the remobilization,deposition and enrichment of gold in crustal sediments. 相似文献
11.
《International Geology Review》2012,54(7):775-777
Three deposits in the eastern and southeastern parts of Afghanistan are genetically and spacially associated with ultrabasic massifs which have clear tectonic contacts with the country rocks and are located within ophiolitic sutures. All the deposits are confined to the marginal portions of the massifs, within and near which acid intrusions are absent and chromite bodies are usually present. The Afghan deposits, representing a variety of genetic types, are spatially confined to the ultrabasic belt of Tethys in the Alpine-Himalayan fold belt and are associated with the Alpine epoch of asbestos formation. 相似文献
12.
尉犁县且干布拉克蛭石矿为特大型,磷灰石矿为大型.蛭石、磷灰石均赋存于磁性较强的透辉石岩及超基性岩中,矿体与围岩间有较明显的磁性差异,含矿母岩70%被第四系覆盖.利用地面磁测,较好地圈定了含矿母岩的边界,提供了含矿体的平面形态及产状,为勘查缩小了靶区.磁法勘探不仅是直接找磁铁矿床及某些有关金属矿床的有效方法,而且在间接寻找非金属矿床上亦能发挥作用. 相似文献
13.
依据区内岩体及围岩662个微金样品分析结果,笔者对基性、超基性岩的含金性及其中金的赋存规律进行了详细研究。确认该区基性、超基性岩体的金背景含量普遍偏高,而且明显高于围岩。同时指出,三条蛇绿岩带金元素丰度呈现自北而南、自东而西递增的趋势。经对金富集地质条件的分析,认为区内金的活化迁移主要受控于与超基性岩带分布近于一致的两条韧性剪切带,并指出断裂破碎带、强蚀变超基性岩体与围岩接触带、热液蚀变带、金属硫化物产出部位及砂金(铂)异常与Au、As、Sb、Cu异常重叠部位是找金的有利地段。在上述地段发现了川刺沟、撒拉河金矿点两处和含金超基性岩体20处。提出四个预测区和七个找金部位。依据硫同位素、矿物包裹体等资料及金矿(化)体的赋存部位,首次提出该区金矿总体可称为蛇绿岩型金矿。成因类型主要属中温变质热液型。 相似文献
14.
青海北祁连山基性、超基性岩含金性研究 总被引：1，自引：0，他引：1
依据区内岩体及围岩662个微金样品分析结果,笔者对基性、超基性岩的含金性及其中金的赋存规律进行了详细研究。确认该区基性、超基性岩体的金背景含量普遍偏高,而且明显高于围岩。同时指出,三条蛇绿岩带金元素丰度呈现自北而南、自东而西递增的趋势。经对金富集地质条件的分析,认为区内金的活化迁移主要受控于与超基性岩带分布近于一致的两条韧性剪切带,并指出断裂破碎带、强蚀变超基性岩体与围岩接触带、热液蚀变带、金属硫化物产出部位及砂金(铂)异常与Au、As、Sb、Cu异常重叠部位是找金的有利地段。在上述地段发现了川剌沟、撒拉河金矿点两处和含金超基性岩体20处。提出四个预测区和七个找金部位。依据硫同位素、矿物包裹体等资料及金矿(化)体的赋存部位,首次提出该区金矿总体可称为蛇绿岩型金矿。成因类型主要属中温变质热液型。 相似文献
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野外调查发现西藏类乌齐地区分布着众多的含镍碳酸岩体,呈十几米至几百米不等的岩株出露。岩体与超基性岩之间具明显的港湾状、枝状侵入接触、岩石不具层理、岩石表现出细粒结晶等粒结构、岩体内见超基性岩捕掳体等特征均表明其为火成碳酸岩岩体。在成分上以菱镁矿为主,岩石中MgO的含量为27.16%~31.75%,为镁质碳酸岩。岩石稀土元素配分曲线呈平缓右倾的轻稀土富集型,轻重稀土元素分馏现象明显,具有明显的Eu正异常和弱的Ce负异常;微量元素显示Rb、Th、Nb、Hf元素相对富集,K、U、Ti元素相对亏损。含镍碳酸岩可能是富CO2的深部流体在中下地壳对超基性岩交代的结果,具备寻找硫化镍矿床的有利条件。 相似文献
17.
《Journal of African Earth Sciences》2008,50(2-4):168-187
The genesis of gem-quality deep green emeralds of Zabara, Sikait and Umm Kabo (South Eastern Desert, Egypt) is to date a controversial topic. The emerald-bearing biotite schists and quartz lenses are interpreted alternatively as a product of (i) thrust-fault-shear zone – controlled large scale alkali-metasomatism driven by post-magmatic fluid flow or of (ii) a large scale interaction between syntectonic pegmatitic magma or hydrothermal fluids with pre-existing basic to ultrabasic rocks, or of (iii) a syn- to post-tectonic regional metamorphism and small scale blackwall metasomatism. Detailed microstructural and chemical analyses of the Egyptian emeralds and their host rocks show that three generations of beryl can be distinguished: a colourless pegmatitic beryl; a pale green Cr-poor beryl crystallized from pegmatite-related hydrothermal fluids; and a deep green Cr- and Mg-rich emerald. The crystallization of the Cr- and Mg-rich emerald was controlled by the very local availability of Cr, Mg and Be-rich metamorphic fluids during the Pan-African tectono-thermal event. Emerald-rich quartz lenses demonstrate that those fluids locally did mobilize quartz, too. The pale green emeralds found within the pegmatites in association with colourless beryl are the product of a mobilization of colourless pegmatitic beryl and/or phenakite by late pegmatitic fluids slightly enriched in Cr by an interaction with the Cr-rich country rocks. The late pegmatitic fluids are typically Na-rich as is demonstrated by the pervasive albitization of the pegmatites. The complex interplay of magmatic and regional metamorphic events during the genesis of the Egyptian emeralds/beryls makes it impossible through stable oxygen isotope data to relate their genesis to the one or the other event. 相似文献
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罗钧林 《华北地质矿产杂志》1999,(2)
金家庄金矿床位于华北地台北缘,尚义一赤城深大断裂带中段,属于产在超基性岩体断裂中的矿床。小张家口超基性岩体是金矿的主要围岩。深大断裂是成矿的先决条件;超基性岩体的存在是成矿的物质基础;中酸性岩浆及多次活动是成矿的关键。 相似文献
20.
广西元宝山区的层状基性-超基性岩带是桂北花岗-绿岩带的超镁铁质熔岩,其岩石化学特征与科马提岩相似,与之有成因关系的矿产,不仅有铂钯矿,还有具很大经济价值的锡矿。后者是一种新型锡矿床,与产于花岗岩内外接触带的锡矿完全不同,它产于基性-超基性杂岩之内,呈层状产出,随地层褶曲而褶曲。矿物组合、地球化学特征均与超基性岩有密切关系,但受到后期热液(含花岗岩事件所产生的热液)的叠加改造作用。 相似文献