大别-苏鲁造山带超高压榴辉岩和脉体磷灰石含氯特征与变质流体演化
摘要
根据磷灰石中的氯组分含量,研究了大别-苏鲁超高压变质带中榴辉岩和其中的脉体形成过程中流体的盐度及其变化.仰口榴辉岩中磷灰石在进变质过程中显示为氯含量增加,反映出俯冲的大陆岩石经受了一个逐步干化和流体活动性降低的过程;在退变质过程中氯含量降低,反映超高压岩石折返过程中流体含量增加.大别-苏鲁超高压变质带一些典型的露头,包括池庄、青龙山、毛北、碧溪岭、毛屋、朱家冲和花凉亭等地的超高压榴辉岩及其中的脉体,其磷灰石成分变化很大,指示榴辉岩相变质和脉体形成过程中流体盐度变化很大,从低盐度流体到高盐度流体均存在,不同露头有所差异.总体来看,不同盐度的流体在变质过程中普遍存在,流体盐度的变化可能与大陆地壳俯冲/折返过程中岩石水化和脱水反应有关.
引文
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15张灵敏,刘景波,程南飞,等.大别-苏鲁高压超高压带榴辉岩和脉体中磷灰石Cl含量和流体盐度关系的研究.岩石学报,2013,29:1525-1539
16翟伟,孙晓明,徐莉,等.苏北青龙山超高压变质榴辉岩流体包裹体特征与流体演化.岩石学报,2005,21:482-488
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20 Zheng Y F.Fluid regime in continental subduction zones:Petrological insights from ultrahigh-pressure metamorphic rocks.J Geol Soc,2009,166:763-782
21 Zheng Y F.Metamorphic chemical geodynamics in continental subduction zones.Chem Geol,2012,328:5-48
2 Selverstone J,Franz G,Thomas S,et al.Fluid variability in 2 GPa eclogites as an indicator of fluid behaviour during subduction.ContribMineral Petrol,1992,112:341-357
3 Philippot P,Chevallier P,Chopin C,et al.Fluid composition and evolution in coesite-bearing rocks(Dora-Maira massif,western Alps):Implication for element recycling during subduction.Contrib Mineral Petrol,1995,121:29-44
4 Scambelluri M,Pennacchioni G,Philippot P.Salt-rich aqueous fluids formed during eclogitization of metabasites in the Alpine continen-tal crust(Austroalpine Mt.Emilius unit,Italian western Alps).Lithos,1998,43:151-167
5 Glassley W E.Elemental composition of concentrated brines in subduction zones and the deep continental crust.Precambrian Res,2001,105:371-383
6 Scambelluri M,Philippot P.Deep fluids in subduction zones.Lithos,2001,55:213-227
7 Svensen H,Jamteit B,Banks D A,et al.Halogen contents of eclogite facies fluid inclusions and minerals:Caledonides,western Norway.JMetamorph Geol,2001,19:165-178
8 Xiao Y L,Hoefs J,van den Kerkhof A M,et al.Fluid history of UHP metamorphism in the Dabie Shan,China:A fluid inclusion and ox-ygen isotope study on the coesite-bearing eclogite from Bixiling.Contrib Mineral Petrol,2000,139:1-16
9 Xiao Y L,Hoefs J,van den Kerkhof A M,et al.Fluid evolution during HP and UHP metamorphism in Dabie Shan,China:Constraintsfrom mineral chemistry,fluid inclusions and stable isotopes.J Petrol,2002,43:1505-1527
10 Fu B,Touret J L R,Zheng Y F.Fluid inclusions in coesite-bearing eclogites and jadeite quartzites at Schuanghe,Dabie Shan,China.JMetamorph Geol,2001,19:531-548
11 Fu B,Zheng Y F,Touret J L R.Petrological,isotopic and fluid inclusion studies of eclogites from Sujiahe,NW Dabie Shan(China).Chem Geol,2002,187:107-128
12 Newton R C,Aranovich L Y,Hansen E C,et al.Hypersaline fluids in Precambrian deep-crustal metamorphism.Precambrian Res,1998,91:41-63
13 Liu J B,Zhang L M,Mao Q,et al.Increasing chlorinity in fluids along the prograde metamorphic path:Evidence from apatite fromYangkou eclogite,Sulu,China.In:Dobrzhinetskaya L F,Faryad S W,Wallis S,et al.,eds.Ultrahigh-Pressure Metamorphism:25 YearsAfter the Discovery of Coesite and Diamond.London:Elsevier,2011.213-242
14 Liu J B,Liu W Y,Ye K,et al.Chlorine-rich amphibole in Yangkou eclogite,Sulu ultrahigh-pressure metamorphic terrane,China.Eur JMiner,2009,21:1265-1285
15张灵敏,刘景波,程南飞,等.大别-苏鲁高压超高压带榴辉岩和脉体中磷灰石Cl含量和流体盐度关系的研究.岩石学报,2013,29:1525-1539
16翟伟,孙晓明,徐莉,等.苏北青龙山超高压变质榴辉岩流体包裹体特征与流体演化.岩石学报,2005,21:482-488
17沈昆,张泽明,石超,等.江苏东海榴辉岩相变质脉体的流体包裹体研究.岩石学报,2008,24:1987-2002
18 Zhang Z M,Shen K,Sun W D,et al.Fluids in deeply subducted continental crust:Petrology,mineral chemistry and fluid inclusion ofUHP metamorphic veins from the Sulu orogen,eastern China.Geochim Cosmochim Acta,2008,72:3200-3228
19 Franz L,Romer R L,Klemd R,et al.Eclogite-facies quartz veins within metabasites of the Dabie Shan(eastern China):Pressure-tem-perature-time-deformation path,composition of the fluid phase and fluid flow during exhumation of high-pressure rocks.Contrib MineralPetrol,2001,141:322-346
20 Zheng Y F.Fluid regime in continental subduction zones:Petrological insights from ultrahigh-pressure metamorphic rocks.J Geol Soc,2009,166:763-782
21 Zheng Y F.Metamorphic chemical geodynamics in continental subduction zones.Chem Geol,2012,328:5-48