oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 36 )

2018 ( 849 )

2017 ( 862 )

2016 ( 900 )

Custom range...

Search Results: 1 - 10 of 44263 matches for " 超镁铁杂岩体 "
All listed articles are free for downloading (OA Articles)
Page 1 /44263
Display every page Item
四川盐边高家村镁铁-超镁铁质杂岩体的形成时代:单颗粒锆石U-Pb和角闪石40Ar/39Ar年代学制约
朱维光,邓海琳,刘秉光,李朝阳,覃喻,骆耀南,李志德,皮道会
科学通报 , 2004,
Abstract: 四川盐边高家村镁铁-超镁铁质杂岩体是一个分异良好的似层状侵入体,该岩体可以分为两个堆积旋回.对高家村杂岩体主体岩相的角闪辉长岩进行系统的单颗粒锆石U-Pb定年以及单矿物角闪石40Ar/39Ar定年的研究,表明高家村杂岩体的主体岩相形成年龄为840±5Ma.对“盐边蛇绿岩”的提法提出了质疑,认为高家村杂岩体的形成很可能与Rodinia超级大陆下的一个超级地幔柱活动有关.以上的研究成果有助于重新认识盐边地区新元古代构造演化特征.
中天山白石泉镁铁-超镁铁质岩体岩石学与矿物学研究
柴凤梅,张招崇,毛景文,董连慧,张作衡,叶会寿,吴华,莫新华
矿物岩石 , 2006,
Abstract: 白石泉地区镁铁一超镁铁质岩体处于塔里木板块前缘活动带与中天山地块接合部位,是中天山地块华力西中期岩浆活动的产物。主要岩石类型有辉石橄榄岩(斜方辉石橄榄岩、斜长二辉橄榄岩)、橄榄辉石岩、橄长岩、辉长岩及角闪辉长岩等,主要造岩矿物为橄榄石、斜方辉石、单斜辉石、角闪石、斜长石及黑云母。橄榄石均为贵橄榄石,其Fo值(78-85)位于含铜镍硫化物矿橄榄石的Fo值范围之内;辉石主要有顽火辉石、古铜辉石、紫苏辉石、透辉石等;斜长石的环带构造较为发育;角闪石的FeO含量随着岩浆的演化逐渐增加。它们与造山带环境中的东疆型镁铁一超镁铁杂岩中的造岩矿物具有相同的特征。这些特征表明了白石泉地区的镁铁一超镁铁质岩体的原始岩浆为高镁的拉斑玄武质岩浆。
新疆北山地区坡北镁铁-超镁铁岩体单斜辉石的矿物学特征及其地质意义
刘艳荣,吕新彪,梅微,代玉才
矿物岩石 , 2012,
Abstract: 单斜辉石是坡北镁铁-超镁铁杂岩体的主要造岩矿物之一,在各岩相中普遍存在。本文对岩体各岩相中单斜辉石的矿物化学组成进行了电子探针和LA-ICPMS分析,以探明岩体性质、形成的构造背景及演化过程。分析表明,单斜辉石主要氧化物含量为:SiO21.05%~54.00%、MgO13.95%~17.64%、CaO19.87%~23.56%、FeO3.44%~6.58%、TiO20.13%~1.36%、Al2O32.17%~4.21%、Na2O0.17%~0.50%、Cr2O30.01%~1.27%。岩石判别图解表明寄主岩浆为亚碱性拉斑玄武岩,形成于岛弧环境。单斜辉石的结晶温度范围介于1141~1221℃。∑REE和(Ce/Yb)N值表明从(异剥)橄榄岩和橄榄单辉辉石岩到橄榄辉长岩和角闪辉长岩,岩浆结晶作用增强。与岩浆正常结晶演化相比,(异剥)橄榄岩和橄榄单辉辉石岩中单斜辉石的SiO2、Na2O含量有所增大,角闪辉长岩和橄榄辉长岩中单斜辉石的CaO含量略有富集,结合前人研究成果和围岩性质,初步认为成岩过程中,可能发生过地壳同化混染作用,其中大理岩为角闪辉长岩和橄榄辉长岩提供了部分Ca元素,而黑云母石英片岩则为(异剥)橄榄岩和橄榄单辉辉石岩贡献了Si、Na等。(异剥)橄榄岩和橄榄单辉辉石岩具较低的FeO含量,此外黑云母石英片岩混入其中,这可能是引起硫化物熔离的重要因素。
河北矾山超镁铁岩正长岩杂岩体中黑云母的特征及其成岩指示意义
牛晓露,杨经绥,冯光英,刘飞
地质学报 , 2015,
Abstract: 河北矾山超镁铁岩正长岩杂岩体侵位于华北克拉通北缘,为硅不饱和过钾质碱性岩,起源于受古亚洲洋俯冲物质改造过的富集岩石圈地幔。矾山杂岩体侵位于晚三叠世,是华北克拉通北缘三叠纪碱性岩带的代表性岩体之一。本文利用电子探针(EMPA)和激光等离子质谱仪(LAICPMS)获得了该特殊岩浆体系下黑云母的主量和微量元素组成,并讨论了其成岩指示意义。矾山杂岩体各类型岩石中的云母均为黑云母,Fe/(Fe+Mg)为0?32~0?57,∑Al为1?179~1?375。黑云母成分记录石榴石辉石正长岩结晶时体系氧逸度Log?f?O??2?=-12?5~-15,温度为680~780℃。矾山杂岩体的黑云母具有极低的稀土元素含量(小于0?100×10??-6?~1?077×10??-6?),对全岩稀土元素配分型式基本上没有影响。在微量元素组成上,黑云母是元素Rb、Ba、Nb、Ta、V、Cr、Co和Ni的主要载体,其Sr、Zr、Hf、Y、Sc、Th和U的含量明显低于全岩。黑云母成分反映矾山杂岩体岩浆体系以富Fe、高氧逸度为特征,这可能是该杂岩体发育具有经济价值铁矿床的原因之一。
四川盐边高家村镁铁-超镁铁质杂岩体的形成时代:单颗粒锆石U-Pb和角闪石40Ar/39Ar年代学制约
朱维光
科学通报 , 2004,
Abstract: 四川盐边高家村镁铁-超镁铁质杂岩体是一个分异良好的似层状侵入体, 该岩体可以分为两个堆积旋回. 对高家村杂岩体主体岩相的角闪辉长岩进行系统的单颗粒锆石U-Pb定年以及单矿物角闪石40Ar/39Ar定年的研究, 表明高家村杂岩体的主体岩相形成年龄为840±5 Ma. 对"盐边蛇绿岩"的提法提出了质疑, 认为高家村杂岩体的形成很可能与Rodinia超级大陆下的一个超级地幔柱活动有关. 以上的研究成果有助于重新认识盐边地区新元古代构造演化特征.
Petrological study for origin of Nanshanling garnet peridotite from Dabie Mountain
大别山南山岭石榴橄榄岩成因的岩石学研究

LU FengXiang,JIN ZhenMin,SANG LongKang,CHU LingLin,JIN ShuYan,
路凤香
,金振民,桑隆康,储玲林,金淑燕

岩石学报 , 2007,
Abstract: 大别山罗田穹隆东南侧的南山岭石榴橄榄岩岩体面积小(173×133m~2),由贵橄榄石(75%)。透辉石(10%)和镁铝石榴石(15%)组成。本文通过岩石学及地球化学研究,并与大别山的碧溪岭、毛屋、饶拔寨、芝麻坊岩体以及其他地区的基性岩浆杂岩体(如红格岩体、元宝山岩体、柴北缘岩体)、残留地幔块体(五大连池、鹤壁、山旺)等不同成因的超镁铁岩进行对比后认为,该岩体属于火成成因,是镁铁-超镁铁杂岩体的一部分。表现在:橄榄岩呈块状构造,矿物分布均匀未见定向排列,镜下呈现典型的火成结构;FeO~T含量高(21.36%),Mg~#(0.77)低,Mg Ni/Fe Mn(3.06)<7,V(175.5×10~(-6))含量高于地幔块体成因的橄榄岩;REE总量偏低,LREE弱富集,(La/Yb)_N=3.1,低于饶拔寨、芝麻坊等残留地幔块体成因的橄榄岩。南山岭橄榄岩在微量元素蛛网图中,具有Ba、U、Pb、Zr、Eu的正异常和Nb的负异常,石榴橄榄岩全岩以及透辉石单矿物都具有高~(87)Sr/86 Sr(0.7088,0.7086)和低ε_(Nd)(t)(-6.55~-6.01)的特征,尽管南山岭与碧溪岭岩体距离很近而且都属于火成成因,但岩石的结构构造、变质变形的印记、REE配分形式和同位素特征都有区别,表明二者的源区及演化经历不同,相比之下,南山岭岩浆源区地壳组分的作用更为明显。在ε_(Nd)(t)-(~(87)Sr/~(86)Sr)_t图解中南山岭橄榄岩的投点十分靠近大别山北麓120~130Ma侵位的祝家铺辉石岩-辉长岩岩体群的投点分布范围,暗示可能有与罗田穹窿西北侧祝家铺岩体群的岩浆活动相对应。
Zircon SHRIMP U-Pb dating of the Fanshan potassic alkaline ultramafite-syenite complex in Hebei Province, China
河北矾山钾质碱性超镁铁岩-正长岩杂岩体的锆石SHRIMP U-Pb年龄

REN Rong,MU BaoLei,HAN BaoFu,ZHAO Lei,CHEN JiaFu,XU Zhao,SONG Biao,
任荣
,牟保磊,韩宝福,张磊,陈家富,徐钊,宋彪

岩石学报 , 2009,
Abstract: As one of alkaline intrusives in northern margin of the North China block, the Fanshan potassic ultramafite-syenite complex in Hebei Province contains the largest endogenous magnetite-apatite deposit of China. However, the pre-existing K-Ar, Rb-Sr and Sm-Nd ages are so different that more precise dating is very important to constrain the timing of the Fanshan complex. This study reports a SHRIMP zircon U-Pb age of 218±2Ma from a pyroxene syenite sample. Because the dated sample was collected from the main part of the complex, which was produced by the last (third-stage) pulse of magmatism, the zircon U-Pb age provides a strong constraint on the timing of the Fanshan complex. This is consistent with the zircon U-Pb ages from the literature for other alkaline intrusives in northern, eastern, and southern margins of the North China block, indicating that the alkaline magmatism at around 220Ma is one of the most important tectonomagmatic events in eastern China.
Geochemical constraints on petrogenesis of Hashatubei ultramafic complex,Inner Mongolia.
内蒙古哈沙图北超镁铁杂岩体成因的地球化学制约

ZHANG MingJie,WANG TingYin,GAO JunPing,LI LiMei,
张铭杰
,王廷印

岩石学报 , 2001,
Abstract: 哈沙图北超镁铁杂岩体位于华北克拉通西北缘,具小规模多岩相的特征,主要由蛇纹石化橄榄岩、橄榄二辉岩、角闪辉石岩、异剥辉石岩及石英闪长玢岩等组成的铁质超镁铁杂岩。岩体由两大系列岩石组成:第一系列岩石结晶粗大,具平坦型稀土元素分配模式,亏损Nb、Ta、Ti等高场强元素(HFSE)和Rb、Cs、Ba等大离子亲石元素(LILE),富集U和Rb,Zr,Hf及HREE等元素含量变化较大,为大陆地壳拉张环境下富集型岩石圈地幔较高程度熔融形成的岩浆经小规模分异后分期侵入原地结晶形成的,在每期岩浆结晶初期存在一定程度的堆晶作用。第二系列岩石呈致密太,磁铁矿含量较高,岩石风化表面呈黄褐色,亏损Rb、Cs、K、Ti,富集Nb、Ta、Pb、LREE,∑REE高,为初始洋壳下富集地幔较低程度熔融形成的岩浆结晶的产物。Nd同位素组成变化较小(^143Nd/^144Nd=0.5122-0.5124),两个系列岩石中分配系数相等的微量元素比值分别分布在两个区域,岩石地球化学特征表明,该岩体为一长寿命的岩浆通道中不同源区、不同构造环境中不同期岩浆的堆积物,岩浆源区为EM1型富集地幔;表明华北克拉通西北缘在古元古代以来存在长期的陆壳增生事件,经历了拉张减薄、初始洋壳演化阶段。
Characteristics and significance of CH4-rich fluid inclusions from the mafic-ultramafic complex at the Xiangshan, eastern Tianshan Mountains, Xinjiang of China
东天山香山镁铁-超镁铁岩中富CH4流体包裹体的特征及其意义

PAN XiaoFei,LIU Wei State Key Laboratory of Lithosphere Tectonic Evolution,Institute of Geology,Geophysics,Chinese Academy of Sciences,Beijing,China,
潘小菲
,刘伟

岩石学报 , 2005,
Abstract: Post-collisional Cu-Ni-bearing mafic-ultramafic intrusive complexes densely occur in the eastern Tianshan Mountains, Xinjiang of China. Compositions of rock and, especially, fluid in their source region remain to be resolved. Xiangshan pluton is typical of the mafic-ultramafic complexes in the eastern Tianshan Mts. It comprises pendotite, gabbro-norite, diorite and gabbro-diabase. Megacrysts of poikilitic hornblende that is abundant in all the rock phases have grown around olivine and labrador, indicating that the parent magma is rich in water. Studied samples were collected from the fresh gabbro-norite in the central body of the Xiangshan pluton. Labrador- and olivine-hosted fluid inclusions occur in isolation or in group without obvious orientation. Fluid inclusion trails were observed occurring parallel to the grain boundary or growth plane of the host mineral. Fluid inclusions are primary or secondary and were trapped during growth of the host mineral or extensive exsolution of fluid from the magma as marked by the crystallization of hornblende. Hence, these fluid inclusions represent fluids derived from the source region. Available stable sulfur and lead isotopic data show meteoric affinity and normal common lead characteristics, respectively. Therefore, crustal contribution for rock and fluid via assimilation or infiltration can be excluded. Bubbles of more than 50 fluid inclusions were analyzed using micro-laser Raman spectrometer. It is shown by the analysis that CH4 and H2O are the dominant gas species, and hydrocarbons C2H2 , C2H6, and C4H6, and N2 are the subordinate gas species in the vapor phase of these fluid inclusions. Four types of vapor compositions are distinguished that include a) CH4-rich vapor,b) H2O-rich vapor, c) H2O + CH4 mixing vapor, and d) multi-species (C2H6 + N2 + CH4 , C2H6 + CH4 + N2 +C4H6) mixing vapor. Therefore, fluids that are brought by the Xiangshan pluton from the mantle source region are rich in H2O and reductive volatiles CH4 etc. Because CO2 fluid instead of CH4 fluid is abundant in the upper mantle whose redox state is near to fayalite-magnetite-quartz buffer, it is likely that the parent magma and inclusion fluids of the Xiangshan pluton derive from the transition zone of the mantle or asthenosphere underneath the Paleozoic orogens of the northern Xinjiang. Subducted slab brought water to the un-oxidized deep mantle during the subduction period before the end of the Early Carboniferous. Mixing of water with the reducing CH4-rich C-H fluids played an important role in the melting of the deep mantle, thereby resulting in the production of widespread post-collisional mafic-ultramafic complexes and the related Cu-Ni sulfide ore deposits.
Characteristics of two mafic-ultramafic rock series in the Xiangshan Cu-Ni-(V) Ti-Fe ore district, Xinjiang
新疆香山铜镍钛铁矿区两个镁铁-超镁铁岩系列及特征

WANG YuWang,WANG JingBin,WANG LiJuan,LONG LingLi,
王玉往
,王京彬,王莉娟,龙灵利

岩石学报 , 2009,
Abstract: 新疆东天山香山地区镁铁-超镁铁杂岩体中产有香山中中型铜镍矿床和香山西大型铜镍-钛铁矿床。通过对这套镁铁-超镁铁岩进行系统的野外研究和采样,对各类岩石进行详细的岩石学和岩石地球化学研究,识别出该区两个具有不同成矿专属性的岩石系列。(1)早期与钒钛磁铁矿矿化有关的岩石系列(简称“钛铁系列”),岩石组合为细晶辉长岩-钛铁辉长岩(钛铁矿石)-含钛(角闪)辉长岩-淡色辉长岩。从钛铁矿石-含钛辉长岩-淡色辉长岩连续演化,矿物组成和岩石结构逐渐过渡,岩石相对偏酸性,化学成分以富碱、富铁、高钛、硅、铝、钙,钙碱指数(calk/m)高而镁铁指数(m/f)低为特征,稀土和微量元素方面斜长石堆积作用和分离结晶作用特征明显;(2)晚期与铜镍硫化物矿化有关的岩石系列(简称“铜镍系列”),岩石组合为超镁铁岩-韵律状橄榄辉长岩-蚀变角闪辉长岩,与前一系列呈侵入关系。该系列岩石组合偏基性,化学成分上明显富镁,贫铁、钛,具相对较低的硅、铝和钾、钠含量,稀土和微量元素配分曲线平缓,与原始地幔/亏损地幔特征相近。此外,本区发育的浅成-超浅成脉岩(辉绿岩类)多为辉长岩类的晚期补充岩相,其岩石化学特征位于两个演化系列的末端,可能是两个演化系列残余岩浆混合-再侵位的产物。
Page 1 /44263
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.