磁铁矿危机与铜金热液成矿
Magnetite Crisis and Copper Gold Mineralization
查看参考文献47篇
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文摘
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磁铁矿结晶造成氧化性岩浆中的硫酸根被还原为硫酸氢根,进而将铜、金等元素以硫酸氢根络合物的形式萃取到流体相中,形成成矿热液,这一现象称之为磁铁矿危机。这一过程是斑岩型和浅成低温热液型铜金矿床成矿的关键因素之一。对于斑岩型矿床,由于成矿体系是处于封闭、半封闭环境,硫酸根的还原过程主要发生在热液中,反应过程中释放出大量的氢离子,使成矿热液的pH值降低,硫酸根氧化还原电位升高,在成矿的后期,往往出现镜铁矿蚀变,氧逸度达到磁铁矿-赤铁矿氧化还原缓冲线附近。对于浅成低温热液型矿床,硫酸根的还原主要发生在岩浆中,反应不释放氢离子,因此体系的氧逸度趋于下降且变化较小。岩体的成矿潜力主要受控于初始铜金含量,而铜金含量则主要受控于氧逸度和源区岩石的性质。年轻的俯冲洋壳发生部分熔融,形成具有高初始铜金含量的氧化性岩浆,是形成斑岩型铜金矿床最重要的地质过程。高硫型浅成低温热液型矿床深部有斑岩型铜金矿床的几率较大。 |
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其他语种文摘
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Magnetite crisis refers to the abrupt decrease of Cu,Au contents in convergent magin magmas induced by magnetite. The crystalization of magnetite in oxidized magmas causes sulfate reduction,forming hydrosulfide complexes that scavenge Cu and Au into hydrous phase,resulting in ore-forming fluids. This is one of the key processes that control porphyry and epithermal Cu,Au mineralizations. For porphyry deposits,the mineralization occurs in closed or semi-closed systems. Sulfate reduction occurs mainly in hydrothermal fluids,releasing large amount of H~+,lowering the pH values and thus elevates the oxidiation potential of sulfate,reaching the magnetite-hematite oxygen fugacity buffer. Consequently,there is usually speculerite alteration at the late stage of porphyry mineralizations. For epithermal deposits,sulfate reduction occurs mainly in the magmas without releasing H~+. Therefore,the oxygen fugacity tends to drop but does not change much. The initial Cu,Au contents,which are the main factors and essential to the mineralization potential of magmas,are controlled by oxygen fugacity and characteristics of source rocks. Subduction of young oceanic crust forms oxidized adakitic magmas with high initial Cu,Au contents,which are favorable for Cu,Au porphyry deposits. High sulfur epithermal deposits are more likely to be associated with porphyry Cu,Au deposits underneath. |
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来源
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矿物岩石地球化学通报
,2015,34(5):895-901 【核心库】
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DOI
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10.3969/j.issn.1007-2802.2015.05.002
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关键词
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板块俯冲
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氧逸度
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磁铁矿
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斑岩型铜金矿床
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浅成低温热液型矿床
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地址
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1.
中国科学院广州地球化学研究所, 中国科学院矿物学与成矿学重点实验室, 广州, 510640
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同位素地球化学国家重点实验室, 同位素地球化学国家重点实验室, 广州, 510640
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语种
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中文 |
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文献类型
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研究性论文 |
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ISSN
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1007-2802 |
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学科
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地质学 |
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基金
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国家自然科学基金
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文献收藏号
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CSCD:5581865
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参考文献 共
47
共3页
|
|
1.
Ballard J R. Relative oxidation states of magmas inferred from Ce (Ⅳ) /Ce (Ⅲ) in zircon: Application to porphyry copper deposits of northern Chile.
Contributions to Mineralogy and Petrology,2002,144(3):347-364
|
CSCD被引
233
次
|
|
|
|
|
2.
Botcharnikov R E. Gold fertility of sulfur-bearing magmas RID B-4726-2008.
Geochimica et Cosmochimica Acta,2010,74(12):A108-A108
|
CSCD被引
1
次
|
|
|
|
|
3.
Chiaradia M. Copper enrichment in arc magmas controlled by overriding plate thickness.
Nature Geoscience,2014,7(1):43-46
|
CSCD被引
53
次
|
|
|
|
|
4.
Cooke D R. Giant porphyry deposits: Characteristics,distribution,and tectonic controls.
Economic Geology,2005,100(5):801-818
|
CSCD被引
265
次
|
|
|
|
|
5.
Defant M J. Derivation of some modern arc magmas by melting of young subducted lithosphere.
Nature,1990,347(6294):662-665
|
CSCD被引
1429
次
|
|
|
|
|
6.
Hofmann A W. Chemical differentiation of the earth: The relationship between mantle,continental crust,and oceanic crust.
Earth and Planetary Science Letters,1988,90(3):297-314
|
CSCD被引
526
次
|
|
|
|
|
7.
Huang R F. Anhydrite stability and the effect of Ca on the behavior of sulfur in felsic magmas.
American Mineralogist,2015,100(1):257-266
|
CSCD被引
6
次
|
|
|
|
|
8.
Jenner F E. The magnetite crisis in the evolution of arc-related magmas and the initial concentration of Au,Ag and Cu.
Journal of Petrology,2010,51(12):2445-2464
|
CSCD被引
32
次
|
|
|
|
|
9.
Jugo P J. Sulfur content at sulfide saturation in oxidized magmas.
Geology,2009,37(5):415-418
|
CSCD被引
66
次
|
|
|
|
|
10.
Jugo P J. Sulfur K-edge XANES analysis of natural and synthetic basaltic glasses: Implications for S speciation and S content as function of oxygen fugacity.
Geochimica et Cosmochimica Acta,2010,74(20):5926-5938
|
CSCD被引
38
次
|
|
|
|
|
11.
Kelley K A. Water and the oxidation state of subduction zone magmas.
Science,2009,325(5940):605-607
|
CSCD被引
94
次
|
|
|
|
|
12.
Keppler H. The distribution of sulfur between haplogranitic melts and aqueous fluids.
Geochimica et Cosmochimica Acta,2010,74(2):645-660
|
CSCD被引
3
次
|
|
|
|
|
13.
Lee C T A. Copper systematics in arc magmas and implications for crust-mantle differentiation.
Science,2012,336(6077):64-68
|
CSCD被引
74
次
|
|
|
|
|
14.
Lee C T A. Economic geology: Copper conundrums.
Nature Geoscience,2014,7(1):10-11
|
CSCD被引
10
次
|
|
|
|
|
15.
Liang H Y. Zircon Ce~(4+) /Ce~(3+) ratios and ages for Yulong ore-bearing porphyries in eastern Tibet.
Mineralium Deposita,2006,41(2):152-159
|
CSCD被引
128
次
|
|
|
|
|
16.
Liang H Y. Porphyry copper-gold mineralization at Yulong,China,promoted by decreasing redox potential during magnetite alteration.
Economic Geology,2009,104(4):587-596
|
CSCD被引
72
次
|
|
|
|
|
17.
Ling M X. Cretaceous ridge subduction along the Lower Yangtze River belt,eastern China.
Economic Geology,2009,104(2):303-321
|
CSCD被引
156
次
|
|
|
|
|
18.
Mavrogenes J A. The relative effects of pressure,temperature and oxygen fugacity on the solubility of sulfide in mafic magmas.
Geochimica et Cosmochimica Acta,1999,63(7/8):1173-1180
|
CSCD被引
62
次
|
|
|
|
|
19.
McDonough W F. The composition of the earth.
Chemical Geology,1995,120(3/4):223-253
|
CSCD被引
1365
次
|
|
|
|
|
20.
Moss R. Gold content of eastern Manus basin volcanic rocks: Implications for enrichment in associated hydrothermal precipitates.
Economic Geology,2001,96(1):91-107
|
CSCD被引
9
次
|
|
|
|
|
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