全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...
地球学报  2006 

中地壳的地球化学动力学和矿石成因

DOI: 10.3975/cagsb.2006.05.08

Keywords: 化学动力学,临界态,矿物与水反应,中地壳

Full-Text   Cite this paper   Add to My Lib

Abstract:

笔者重点进行了大于300℃——在近临界区至超临界区条件下的硅酸盐矿物与水反应动力学实验。矿物(钠长石Ab、透辉石Di、阳起石Act和磁铁矿Mt)的溶解反应动力学实验是使用流体通过叠层反应器的开放体系在25~400℃和22MPa下完成的。实验发现矿物在300℃至400℃范围,在跨越水临界点时出现反应速率的涨落。各种多金属氧化物硅酸盐与水反应时,各个元素溶解到溶液里的释放速率一般不一样,常称为一致溶解作用。但是,在近300℃变为一致溶解作用。实验发现在22MPa时硅酸盐矿物的最大溶解反应速率多是在300℃,如硅的最大释放速率是在300℃。其余元素如Na、K、Mg、Ca、Fe、Al等释放速率在<300℃22MPa时都高于硅的释放速率,在>300℃时硅的释放速率要高于其它元素的释放速率。确切地说,金属与氧之间的键的性质决定了它们(金属氧化物)与水之间反应速率。在一般情况下,Na-Obr,Ca-Obr,Mg-Obr,Al-Obr和Si-Obr的键桥(br),它们之间相对地由具有离子键性质逐步变为具有极性键的性质。由常温常压到亚临界区(300~374℃22MPa),再到大于临界点374℃、22MPa进入超临界区,水的性质随温度、压力变化。水由容易溶解离子键逐渐变为容易打破极性键。笔者还研究了黑钨矿、锡石(玄武岩、花岗闪长岩)与水在250~400℃条件下的反应动力学过程,得出了相同的结果。实验均发现在跨越水临界点时矿物(或岩石)与水反应的动力学涨落。这些实验结果可以用于说明中地壳上部的水/岩相互作用的特征。发生于中地壳的水、岩相互作用大多是在300~450℃和20~50MPa条件下进行的。各地区的地壳厚度不一,中地壳温度压力并不完全相同。模拟中地壳条件下水/岩相互作用实验,目的主要是研究矿物(或岩石)在300~450℃条件下反应动力学过程。已有热液矿床矿物流体包体数据表明:有一批矿床的主要矿石形成于300~500℃,低于NaClH2O溶液临界线的条件。中地壳的流体处于由亚临界态跨越临界态,进入超临界流体太的演化过程。这种流体的性质变化会引起水/岩相互作用的反应动力学涨落和矿石大量沉淀。

References

[1]  Hu Shumin;Zhang Ronghua;Zhang Xuetong.A Study of Near-and Super-Critical Fluids Using Diamond Anivil Cell and inSitu FT-IR Spectroscopy[J].Acta Geologica Sinica,2000(02)doi:10.1111/j.1755-6724.2000.tb00485.x
[2]  Barnes H L,Measuring thermodynamically interpretable solubilities at high pressures and temperatures,New York:Pergamon Press,1981.
[3]  Bodnar R J;Burham C W;Sterner S M,Synthetic fluid inclusions in natural quartz.Ⅲ Determination of phase equilibrium properties in the system H2O-NaCl to 100℃ and 1500 bars,Geochimica et Cosmochimica Acta,1985.
[4]  Zhang Ronghua;Hu Shumin Experimental study of dissolution rates of fluorite in HCl-H2O Solutions [J] 2006
[5]  Zhang Ronghua ;Hu Sumin,Experimental observation of deep crust fluid-NaCl aqueous solution at elevated temperature and pressures and its significance,Chinese science bulletin?,1999, 44(7).
[6]  Zhang R;Hu S;Tong J;Jiang L,Mineral -fluid reaction kinetics in open systems,北京:科学出版社,1998.
[7]  Zhang R;Hu S;Su Y.Alteration zoning and kinetic rocesses of mineral-water interactions[J].Acta Geologica Sinica,2002(03)
[8]  Zhang R;Hu S,Chemical kinetics of minerals in hydrothermal systems and mass transfer,北京:科学出版社,1992.
[9]  Ronghua Zhang;Shumin Hu Hydrothermal study using a new diamond anvil cell with in situ IR spectroscopy under high temperatures and high pressures [J] 2004
[10]  Shvarov Yu W,A numerical criterion for existence of the equilibrium state in an open chemical system,Science Geol Sinica,1989(04).
[11]  Bischoff J L;Pitzer K S,Liquid-vapor relations for the system NaCl-H2O:summary of the P-T-X surface from 300 to 500℃,A Journal of S,1989.
[12]  张荣华;胡书敏;张雪彤;苏艳丰,重要金属矿来源-迁移-堆积过程和化学动力学,北京:科学出版社,2005.
[13]  Eric H. Oelkers ;Jacques Schott,Experimental study of kyanite dissolution rates as a function of chemical affinity and solution composition,Geochimica et Cosmochimica Acta?,1999, 63(6).
[14]  WILLIAM M. MURPHY ;ROBERTO T. PABALAN ;JAMES D. PRIKRYL ;CHRISTOPHER J. GOULET,REACTION KINETICS AND THERMODYNAMICS OF AQUEOUS DISSOLUTION AND GROWTH OF ANALCIME AND Na-CLINOPTILOLITE AT 25℃,American Journal of Science?,1996, 296(2).
[15]  Murphy W M;Helgeson H C,Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions.Ⅳ.Retrieval of rate constants and activation parameters for the hydrolysis of pyroxene,wollastonite,olivine andalusite,quartz,and nepheline,American Journal of Science,1989.
[16]  Murphy W M;Helgeson H C,Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions.Ⅲ Activated complexes and the pH-dependence of the rates of feldspar,pyroxene,and olivine hydrolysis,Geochimica et Cosmochimica Acta,1987.
[17]  Mogollon J L;Ganor J;Soler J M;Lasaga A C Column experiments and the full dissolution rate law of gibbsite [J] 1996
[18]  Lasaga A C,Rate laws of chemical reactions,Reviews in Mineralogy,1981.
[19]  Knauss K G;Wolery T J,Dependence of albite dissolution kinetics on pH and time at 25℃ and 70℃,Geochimica et Cosmochimica Acta? ,1986, 50.
[20]  Hellmann R,The albite-water system:part ii.The time-evolution of the stochiometry of dissolution as a function of pH at 100,200,and 300℃,Geochimica et Cosmochimica Acta,1995.
[21]  Brimhail G H;Crerar D A,Ore Fluids:magmatic to supergene,Mineralogical Society of America,1987.
[22]  Hellmann R;Crerar D;Zhang R,Albite feldspar hydrolysis to 300℃.Solid State Ionics,32/33.In reactivity of solids,1989.
[23]  Barnes H L,Geochemistry of hydrothermal ore deposits A WileyInterscience Publication,John Wiley and Sons,Inc,1979.
[24]  Jonhson J W;Norton D,Critical phenomena in hydrothermal systems:state,thermodynamic,electrostatic,and transport properties of H2O in the critical region,American Journal of Science,1991.
[25]  张荣华;胡书敏.地球深部流体演化与矿石成因[J].地学前缘,2001(04)
[26]  Bodnar R J,Sythetic fluid inclusions:Ⅻ.The system H2O-NaCl experimental determination of the halite liquidus and isochores for a 40% NaCl solution,Geochimica et Cosmochimica Acta,1994(03).
[27]  Zhang R;Hu S;Zhang X.Kinetics of hydrothermal reactions of minerals in near-critical and supercritical water[J].Acta Geologica Sinica,2000(02)
[28]  Zhang R;Posey-Dowty J;Hellmann R;Borcsik M Crerar D Hu S,Kinetics of mineral-water reactions in hydrothermal flow systems at elevated temperatures and pressures,Science in China Ser B,1990(09).
[29]  ZHANG Ronghua ;HU Shumin,Reaction kinetics of fluorite in flow systems and surface chemistry,Science in China. Series D, Earth sciences?,1996, 39(6).
[30]  Zhang R,Sulfur isotopes and pyrite-anhydrite equilibrium in a volcanic basin hydrothermal system of the Middle to Lower Yangtze River valley,Economic Geology,1986.
[31]  Souririajan S;G Kennedy,The H2O-NaCl system at elevated temperatures and pressures,American Journal of Science,1962.
[32]  Bischoff J L,Densities of liquids and vapors in boiling NaCl-H2O solutis:A PVTX summary of from 300 to 500℃,A Journal of S,1991.
[33]  Aagaard P;Helgeson H C,Thermodynamic and kinetic constraints on reaction rates among minerals and aqueous solutions.l.Theoretical considerations,AMERICAN JOURNAL OF SCIENCE? ,1982, 282.
[34]  Shaw R W;Brill T B;Ecker C A;Frank E U,Supercritical water,Special Report C and EN,1991.
[35]  Oelker E H;Schott J;Davidal J L,The effect of aluminum,pH and chemical affenity on the rates of aluminosillicate dissolution reactions,Geochimica et Cosmochimica Acta,1994.
[36]  Meyer C;Hemley J J,Wall rock alteration:in Geochemistry of hydrothermal Ore Depoists,New York,Holt,Rinehart and Winston,1967.
[37]  Fournier R O,The behavior of silica in hydrothermal solutions,series ed:Robertson,Journal of M Review of Economic Geology,1985.
[38]  Davidal JL;Schott J;Dandurand JL,An experimental study of kaolinite dissolution and precipitation kinetics as a function of chemical affinity and solution composition at 150℃,40 bars,and pH 2,6.8,and 7.8,Geochim Cesmochim Acta? ,1997, 61.
[39]  Davidal J L;Dandurand J L;Schott J,Dissolution and precipitation kinetics of kaolinite as a function of chemical affinity (T = 150C,pH = 2 and 7.8),Park city Utah:Rotterdam.Balkema,1992.
[40]  Chou L;Wollast R,Steady-state kinetics and dissolution mechanisms of albite,AMERICAN JOURNAL OF SCIENCE,1985.
[41]  Chou L;Wollast R,Study of the weathering of albite at room temperature and pressure with a fluidized bed reactor,Geochimica et Cosmochimica Acta,1984.
[42]  Brown P E;Lamb W M,P-V-T properties fluids in the system H2O-CO2-NaCl New graphical presentations and implications for fluid inclusion studies,Geochimica et Cosmochimica Acta,1989.
[43]  Bondar R;Vityk M,Interpretation of microthermometric data for H2O-NaCl dluid inclusions,Benedentto de Vivo and Maria Luce Frezzotti,1994.

Full-Text

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133