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磷灰石中磁黄铁矿出溶结构的发现

岩石学报 2005年第2期21卷 405-410页

作者：朱永峰 Massonne H J 造山带与地壳演化教育部重点实验室 institut für mineralogie und kristallchemie universitt stuttgart Azenbergstr18D-70174 StuttgartGermany

中国东部苏鲁地区(江苏赣榆)出露大理岩-榴辉岩块体,其菱镁矿大理岩中保存的白云石分解结构表明地壳物质俯冲深度达到-200公里。在与该大理岩共生的榴辉岩中,我们发现了磷灰石的磁黄铁矿出溶结构。磷灰石是该榴辉岩的主要副矿物,其自形... 详细信息

中国东部苏鲁地区(江苏赣榆)出露大理岩-榴辉岩块体,其菱镁矿大理岩中保存的白云石分解结构表明地壳物质俯冲深度达到-200公里。在与该大理岩共生的榴辉岩中,我们发现了磷灰石的磁黄铁矿出溶结构。磷灰石是该榴辉岩的主要副矿物,其自形程度较高,与石榴石共生。样品中几乎所有磷灰石均发育出溶结构,至少存在两组相互垂直的出溶棒,它们各自严格沿同一个方向分布。出溶棒形状规则,宽度相近(fe和S两种元素组成,但不能准确地确定其fe/S比值。我们把这种出溶棒初步确定为磁黄铁矿(fe1-xS)。磷灰石由于含大量稀土元素和挥发性组分如OH、f、Cl等以及我们所观察到的S,它的深循环因此可能对地球的水、硫以及其它挥发性组分的全球平衡具有重要影响。本文报道的磷灰石中磁黄铁矿出溶结构为深入探讨这个基本科学问题提供了一个新的突破口。

关键词：苏鲁超高压地体榴辉岩出溶结构磁黄铁矿大陆物质深循环

Polymetamorphism of the Variscan Basement of the Moldanubian Black forest (Germany) Documented in Zircon and Garnet Minerals from Gneisses

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Chinese Journal Of Geochemistry 2002年第2期21卷 107-119页

作者：陈福坤 institut für mineralogie Petrologie und Geochemie Universität Tübingen Tübingen Germany institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

t tübingen Wilhelmstrasse 56,72074 tübingen, Germany)2) (institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China) Abstract: High-grade metamorphic Variscan basement is exposed in the Moldanubian zone of the Black forest (Bf), being the internal zone of the European Variscan belt. Zircon grains from K-rich felsic orthogneisses and an anatectic paragneiss in the Moldanubian Black forest demonstrate a multi-stage crystallization at ～600 Ma, ～480 Ma, ～400-380 Ma, and \{～350\} Ma. the last three stages of crystallization probably represent metamorphic overprint during pre-Variscan and Variscan metamorphism. Using stepwise leaching procedures, garnet minerals from felsic orthogneisses as well as paragneisses in the Moldanubian Black forest yielded Early Carboniferous Sm-Nd ages (～330-340 Ma), which are consistent with the well-constrained Variscan Ht metamorphic event, and Early Palaeozoic (～480 Ma) to Devonian (～400-370 Ma) Pb-Pb ages. the coincidence of growth time for zircon and garnet minerals at Early Palaeozoic is interpreted as dating a metamorphic event. these garnet data demonstrate that the Moldanubian Bf basement underwent at least two metamorphic events during the Early Palaeozoic and Early Carboniferous. During the Variscan Ht metamorphism, the Sm-Nd system of garnet was disturbed, but not the U-Pb system, implying the peak metamorphic temperature was lower than ～800℃.

关键词：铅同位素定年锆石石榴石变质作用德国

thermal evolution of an ancient subduction interface revealed by Lue Hf garnet geochronology, Halilba■? Complex(Anatolia)

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Geoscience frontiers 2019年第1期10卷 127-148页

作者： Amaury Pourteau Erik E.Scherer Simon Schorn rebecca Bast Alexander Schmidt Lisa Ebert institut für Erd- und Umweltwissenschaften Universit?t Potsdam Earth Dynamics research Group ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS) The Institute for Geoscience Research (TIGeR) School of Earth and Planetary Sciences Curtin University Münster Isotope research Centre Institut für Mineralogie Westf?lische Wilhelms-Universit?t Münster Department of Geological Sciences University of Cape Town institut für Geologie und mineralogie Universit?t zu K?ln

the thermal structure of subduction zones exerts a major influence on deep-seated mechanical and chemical processes controlling arc magmatism, seismicity, and global element cycles. Accretionary complexes exposed inland may comprise tectonic blocks with contrasting pressureetemperature(Pe t)histories, making it possible to investigate the dynamics and thermal evolution of former subduction interfaces. With this aim, we present new Lue Hf geochronological results for mafic rocks of the Halilbag?Complex(Anatolia) that evolved along different thermal gradients. Samples include a lawsoniteeepidote blueschist, a lawsoniteeepidote eclogite, and an epidote eclogite(all with counter-clockwise Pe t paths),a prograde lawsonite blueschist with a "hairpin"-type Pe t path, and a garnet amphibolite from the overlying sub-ophiolitic metamorphic sole. Equilibrium phase diagrams suggest that the garnet amphibolite formed at w0.6 -0.7 GPa and 800 -850℃, whereas the prograde lawsonite blueschist records burial from 2.1 GPa and 420℃ to 2.6 GPa and 520℃. Well-defined Lue Hf isochrons were obtained for the epidote eclogite(92.38 ± 0.22 Ma) and the lawsoniteeepidote blueschist(90.19 ± 0.54 Ma),suggesting rapid garnet growth. the lawsoniteeepidote eclogite(87.30 ± 0.39 Ma) and the prograde lawsonite blueschist(ca. 86 Ma) are younger, whereas the garnet amphibolite(104.5 ± 3.5 Ma) is *** data reveal a consistent trend of progressively decreasing geothermal gradient from granulite-facies conditions at ~104 Ma to the epidote-eclogite facies around 92 Ma, and the lawsonite blueschist-facies between 90 Ma and 86 Ma. three Lue Hf garnet dates(between 92 Ma and 87 Ma) weighted toward the growth of post-peak rims(as indicated by Lu distribution in garnet) suggest that the HP/Lt rocks were exhumed continuously and not episodically. We infer that HP/Lt metamorphic rocks within the Halilbag?Complex were subjected to continuous return flow, with "warm" rocks being exhumed during the tectonic bur

关键词： Subduction Lu/Hf dating of garnet Metamorphic sole Eclogite Blueschist Lawsonite

Garnet Sm-Nd and U-Pb systems: A case study of a granulite from the European Variscan belt

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Chinese Science Bulletin 2002年第15期47卷 1284-1288页

作者： CHEN fukuninstitut fur mineralogie, Petrologie und Geochemie, universitat tubingen, 72074 tubingen, Germany institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China institut für mineralogie Petrologie und Geochemie Universität Tübingen Tübingen Germany institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

this study presents zircon and garnet ages of a mafic granulite from the high-grade Variscan basement of the Black forest, Germany and discuss isotope closure temperature of garnet Sm-Nd and U-Pb systems. Zircon grains yield 207Pb/206Pb ages between -340 and -414 Ma by the U-Pb and evaporation methods. In contract, garnet dating gives Sm-Nd and Pb-Pb isochron ages of (398±3) Ma and (411±14) Ma, respectively, which are older than most of zircon ages. these data imply that most of zircons lost radiogenic Pb, probably due to metamictization or recrystallisa-tion during the granulite-facies metamorphism (-800°C) at -340 Ma. Garnet Sm-Nd and U-Pb systems preserve chronological information of pro-grade metamorphism, probably profiting from a fluid-absence metamorphic environment. these results demonstrate that garnet mineral can be a better candidate than zircon mineral to date high-grade metamorphism by the U-Pb and Sm-Nd methods in some cases.

关键词： Variscan granulite garnet Sm-Nd U-Pb.

A Correction Approach to the Common Pb Contribution to ^(207)Pb/^(206)Pb ratios Obtained by the Zircon Evaporation technique

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Chinese Journal Of Geochemistry 2001年第2期20卷 189-192页

作者：陈福坤 institut für mineralogie Petrologie und Geochemie Universität Tübingen Tübingen Germany institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

An approach is recommended for the correction of common Pb contribution to \{\{\}\+\{207\}Pb\}/\{\{\}\+\{206\}Pb\} ages obtained by the zircon evaporation technique. A comparison with that by Cocherie et al. (1992) shows that two approaches yield similar results in the \{\{\}\+\{207\}Pb\}*/\{\{\}\+\{206\}Pb\}* ratios. But when using the new approach, only two errors of the measured \{\{\}\+\{204\}Pb\}/\{\{\}\+\{206\}Pb\} and \{\{\}\+\{207\}Pb\}/\{\{\}\+\{206\}Pb\} ratios are introduced to the calculated \{\{\}\+\{207\}Pb\+*\}/\{\{\}\+\{206\}Pb\+*\} ratios.

关键词：铅同位素放射性锆石同位素地质学

Experimental constraints on the genesis of Jadeite quartzite from Shuanghe,Dabie Mountain ultra-high pressure metamorphic terrane

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Science China Earth Sciences 2014年第1期57卷 104-116页

作者： ZHANG Yanfei WU Yao WANG Chao JIN ZhenMin Hans-Peter SCHErtL State Key Laboratory of Geological Processes and Mineral resources China University of Geosciences institut für Geologie Mineralogie und Geophysik Ruhr-Universit t Bochum 44780 Bochum Germany

Jadeite quartzite, essentially a two-phase rock made up of jadeite and quartz, is one of the most important UHP lithologies occur- ring in the Dabie Mountain ultrahigh pressure metamorphic belt and forms layers in biotite-plagioclase gneiss. High pressure- high temperature studies on natural albite from the country rock gneiss were undertaken to reveal the--in parts----complex mineralogical changes that occur in the jadeite quartzite during prograde metamorphism. Experiments were conducted at 800- 1200~C, in the pressure range of 2.0-3.5 GPa. One of the most intriguing results shows that the low pressure boundary of the jadeite＋coesite stability field is located between about 3.2 GPa at 1000~C and 3.4 GPa at 1200~C, thus about （0.2-0.3）_＋0.1 GPa higher than the quartz-coesite transition curve, given the uncertainty in the present study. Minor amounts of sodium and aluminum entering the structure of quartz and the intimate intergrowth texture of the run products may contribute to the ob- served pressure shift. Combined petrological and mineralogical studies on the run products and the natural rocks yield the fol- lowing prograde reaction sequence to have occurred： the protolith of the jadeite- quartzite from Dabie Mountain is an albitized siltstone/greywacke characterized by an albite＋quartz assemblage. During prograde metamorphism albite breaks down to form jadeite＋quartz and thus at this stage two types of quartz can be distinguished whereas type-I-quartz already existed in the pro- tolith, type-II-quartz represents a newly formed reaction product of albite. During further P-t-increase the pure type- I-quartz was transformed to coesite, whereas type-II-quartz （together with jadeite） was still present as a stable phase because of its im- purities of Na and A1. At a later stage during further subduction, type-II-quartz also decomposes to form coesite. these studies represent an important puzzlement for a better understanding of the evolution of jadeite- quartzite fro

关键词： jadeite-quartzite high.pressure experiment albite

中国大陆科学钻探主孔中磷灰石的磁黄铁矿出溶结构

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岩石学报 2007年第12期23卷 3249-3254页

作者：朱永峰 H．-J．Massonne 北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室 institut für mineralogie und kristallchemie Universitt StuttgartAzenbergstr.18D-70174 StuttgartGermany

在中国大陆科学钻探主孔中部的榴辉岩样品B1021r642P40a、B1039r646P47a、B1046r648P4c和B1053r649P74k中,我们发现了磷灰石的磁黄铁矿出溶结构。磷灰石是该榴辉岩的主要副矿物,其自形程度较高,与石榴石共生。样品中几乎所有磷灰石均发... 详细信息

在中国大陆科学钻探主孔中部的榴辉岩样品B1021r642P40a、B1039r646P47a、B1046r648P4c和B1053r649P74k中,我们发现了磷灰石的磁黄铁矿出溶结构。磷灰石是该榴辉岩的主要副矿物,其自形程度较高,与石榴石共生。样品中几乎所有磷灰石均发育出溶结构,至少存在两组相互垂直的出溶棒。出溶棒形状规则,一样宽(fe和S两种元素组成。由于还不能准确地确定其fe/S比值,初步确定其为磁黄铁矿(fe1-xS)。磷灰石由于含大量稀土元素和挥发性组分如OH、f、Cl和S,它的深循环因此可能对地球的水、硫以及其它挥发性组分的全球平衡具有重要影响。

关键词：中国大陆科学钻探苏鲁超高压地体榴辉岩磷灰石出溶结构磁黄铁矿

Crystal morphology of sucrose influenced by rotation axes parallel to growth planes

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Chinese Science Bulletin 2000年第16期45卷 1468-1471页

作者： C.Silber H.follner institut für mineralogie und Mineralische rohstoffe der technischen universitat Clausthal Adolph-Roemer-Str.2AD-38678 Clausthal-ZellerfeldDeutschlandInstitut Für Mineralogie und Mineralische Rohstoffe der Technischen Universitat ClausthalAdolph-Roemer-Str.2AD-38678 Clausthal-ZellerfeldDeutschland

three different types of growth forms of sucrose (P21) were found by calculating with the fourier transform method of crystal morphology. the observed central distances of the (100) and (001) faces are smaller than those calculated. It will be shown that the two-fold screw axis, which runs parallel to these faces, influences the rate of growth. the effectiveness of these symmetry elements is relative to the rotation angle around the face normal.

关键词： sucrose crystal growth mechanism symmetry dependent growth fourier transform method of morphology.

AMPLItUDE DEPENDENt INtErNAL frICtION Of SPHALErItE tYPE SEMICONDUCtOrS

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AMPLITUDE DEPENDENT INTERNAL FRICTION OF SPHALERITE TYPE SEM...