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安徽黄山花岗岩岩石学、矿物学及地球化学研究 总被引：14，自引：4，他引：10
安徽黄山复式岩体位于扬子板块东南缘，江南陆内造山带内。黄山复式岩体由太平花岗闪长岩岩体和黄山花岗岩岩体组成。根据岩体的接触关系和各期次岩石的矿物学及岩石学特征，可以将黄山花岗岩岩体分为4个期次：第一期为中粒二长花岗岩；第二期为粗粒似斑状花岗岩；第三期为中细粒斑状花岗岩；第四期为粗粒含斑花岗岩。从矿物的组成上来看，各期次的岩石均为广义的花岗岩类，主要矿物以石英和长石为主，太平岩体和黄山岩体中的斜长石均表现出钠长石的特点，同时黄山岩体特征的出现条纹长石。各期次岩体均含有少量的铁白云母，显示出过铝质的特点。各期次岩石总体具有高硅（SiO2含量大于75%）、高碱（ALK含量大于7.9%）、低钙（CaO含量小于1%）及高FeOT/MgO比值（13~37）的特点。同时岩石强烈富集稀土元素（除Eu出现明显的负异常）、Zr、Hf、Nb等高场强元素，贫Ba、Sr、Ni，高10000×Ga/Al（比值大于2.6），这些特征均指示黄山复式岩体具有A型花岗岩的特点。通过Eby的判别图解将其进一步划分为A2型花岗岩，代表其形成于拉张的构造背景之下。结合Sm-Nd同位素特征（εNd(t)= -4. 2 ~ -5.6），确定黄山复式岩体的源区物质可能为一套元古宙的火山岩。同时稀土模拟结果表明，黄山岩体的原始岩浆是这种源区大约20%部分熔融的产物。岩体形成于斜向俯冲引发的陆内剪张环境内。 相似文献
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狮吼山矿区是江西省内规模最大的矽卡岩型硫铁多金属矿床，伴生W、Cu、Au多种成矿元素，成矿作用与矿区出露的茶山迳复式花岗岩体有关。岩体主要包括茶山迳似斑状黑云母二长花岗岩和莲湖细粒二长花岗岩两期，为研究成矿岩体的侵位时代、岩石成因及与成矿的关系，本次工作进行了U-Pb锆石定年、岩相学和岩石地球化学等测试分析。结果表明：岩体具有高硅、高钾、富铝的特征，属高钾钙碱性系列花岗岩；轻重稀土元素分馏明显，均为右倾型，弱Eu负异常，以富集Cs、Rb、Th、U、Pb，亏损Ba、Nb、Sr、和Ti等元素为主要特征，属于低Ba-Sr壳源花岗岩类；锆石具较好晶形，具典型岩浆锆石特征，利用LA-ICP-MS进行U-Pb测年，获得谐和年龄为（162.4±0.6）Ma（MSWD=1.8），加权平均年龄为（162.4±1.4）Ma（MSWD=1.4），谐和年龄与加权平均年龄在误差范围内高度一致，表明茶山迳复式岩体侵位于燕山早期中侏罗世；综合考虑岩体矿物组合、主微量元素及高分异特征，认为其成因分类应属于S型花岗岩；对比中国花岗岩成矿元素平均含量，茶山迳两期花岗岩均具有较高的W、Mo、Bi、Pb等成矿元素含量，可同时为成矿作用提供热源、流体及物质。 相似文献
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应用岩石学、矿物学、地球化学及岩浆物理学等的理论和方法，对苏州地区Ｉ型和Ａ型花岗岩的特征及成因进行了对比研究，得出以下主要结论：Ｉ型花岗岩为晚侏罗世火山弧压性环境产物，侵位较深；而Ａ型者为Ａ２型花岗岩，为早白垩世造山后张性环境产物，侵位较浅，具晶洞构造．Ａ型比Ｉ型花岗岩以酸度、碱度、Ａｌ，Ｆ含量高而Ｈ２Ｏ＋含量低，以ＲＥＥ及不相容元素丰度高，负Ｅｕ异常强，而ｗ（ＬＲＥＥ）／ｗ（ＨＲＥＥ）低为特色．Ａ型者矿物结晶顺序先浅色后暗色，暗色矿物以富铁贫镁、ＲＥＥ分配系数高及负Ｅｕ异常明显及长石富碱贫钙，而与Ｉ型花岗岩不同．Ａ型者副矿物４０余种，属锆石－褐帘石－萤石型，锆石结晶温度高，（１１０），（１１１）晶面发育；而Ｉ型者仅１０余种，属榍石－锆石－磷灰石型，锆石结晶温度低，（１００），（３１１）晶面发育．Ｉ型花岗岩为幔源岩浆与下地壳部分熔融岩浆混合及ＡＦＣ作用产物，而Ａ型花岗岩为残余下地壳（麻粒岩相）熔融后分离结晶产物，二者并非同源岩浆演化关系．Ａ型比Ｉ型岩浆来源浅，酸度大，含水少；故岩浆密度小，粘度大，上升慢，冷凝长．受密度筛影响，Ａ型花岗岩岩浆房及侵位深度小于Ｉ型 相似文献
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扬子克拉通北缘的铁船山岩体形成于新元古代，其岩石类型为霓石－钠铁门石花岗岩，岩石富碱质、Ｓｔ、Ｆｅ、ＲＥＥ和高场强元素，而贫Ａｌ、Ｃａ、Ｍｇ、Ｓｒ、Ｂａ、Ｃｏ、Ｎｉ等组分，δＥｕ＝０．２０，Ａ／ＫＮＣ＝０．８５，Ｋ２Ｏ＋Ｎａ２Ｏ／Ａｌ２Ｏ３＝１．０９，Ａ·Ｒ＝９．２８，岩石属典型的Ａ型花岗岩，Ｎｄ、Ｓｒ和Ｏ同位素示踪反映其成岩物质来自于壳幔混合源区。根据区域地质背景的综合分析，岩体形成于活动陆缘的张裂构造环境，属活动板块边缘拉张型花岗岩。 相似文献
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大别山超高压带中变质花岗岩特征：（１） 岩石组合较单一,以二长花岗岩（ 原岩） 为主,缺乏中基性岩和正长岩类;（２） 具鳞片花岗变晶结构,片麻状构造,保留残存的岩浆岩组构;（３） 与榴辉岩及其它超高压变质岩石有明显侵入接触关系,并可见有其捕虏体;（４） 岩石化学表现为富硅、富碱、贫钙、贫镁等特征,一般地ＳｉＯ２ ＞ ７６ ％ ,（ Ｎａ２ Ｏ＋ Ｋ２ Ｏ） ＞ ８ ％ ,ＣａＯ＜ ０ ．５ ％ ,ＭｇＯ ＜ ０ ．４ ％ ;（５） 痕量元素表现为Ｚｒ 、Ｙ、Ｎｂ 、ＲＥＥ 含量高,Ｓｒ 、Ｓｃ 、Ｖ、Ｎｉ 等低;（６） 变质矿物组合为斜长石＋ 石英＋ 钾长石＋ 白云母＋ 石榴石＋ 绿帘石,属于低角闪岩相。（７） 锆石Ｕ － Ｐｂ 同位素年龄值为６８５ ±４１ Ｍａ 。大别山超高压变质带中变质花岗岩为Ａ 型花岗岩,更接近Ａ２ 亚类。变质Ａ 型花岗岩的确定,对进一步认识大别山的大地构造演化、榴辉岩等超高压变质带的形成、折返机制等提供了重要地质依据。 相似文献
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西昆仑山A型花岗岩带的发现及其地球动力学意义 总被引：18，自引：0，他引：18
西昆仑山发育一条醒目的Ａ型花岗岩带,空间上与库地幔台展布范围相一致;它形成于印支晚期,与海西晚期Ⅰ型花岗岩共生;岩石相对富碱、ＬＲＥＥ、Ｙ、Ｎｂ、Ｚｒ,贫Ａ１、Ｍｇ、Ｃａ、Ｂａ、Ｓｒ及过渡元素,又以ＳｉＯ２含量范围宽（６６％～７７％）为其显著特色,与澳大利亚东部ＣｈａｅｌｕｎｄｉＡ型花岗岩极为相似。研究表明,花岗岩属Ａ１型,形成于造山晚期相当稳定的拉张环境,是在岩石圈拆沉过程中侵位的。 相似文献
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浙闽沿海地区Ⅰ型—A型复合花岗岩体的地球化学及成因 总被引：11，自引：2，他引：9
以鼓山－魁岐,青田和普陀山桃花岛三个典型岩体为例,系统研究了浙闽沿海Ｉ型－Ａ型复合花岗岩体的地质和地球化学特征,研究结果表明：复合岩体中Ⅰ型与Ａ型花岗岩在主量,微量和稀土元素特征上均存在明显变异。总体而言,Ａ型花岗岩较之Ｉ型花岗岩富硅,富碱,贫钙,镁,铝,并具偏高的Ｒｂ／Ｓｒ,Ｒｂ／Ｂａ,Ｇａ／Ａｌ和偏低的ＬＲＥＥ／ＨＲＥＥ比值及显著的铕负异常。 相似文献
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新疆吉木乃县阔依塔斯花岗岩的地球化学及构造意义 总被引：9，自引：0，他引：9
阔依塔斯岩体由似斑状碱性花岗岩、中细粒碱性花岗岩和中粗粒碱性花岗岩组成。具有明显的高硅、碱、高ＲＥＥ,低钙、镁,低δ（１８Ｏ）,铕负异常等特征,与国内外典型“Ａ”型花岗岩特征一致。研究表明,该岩体为Ａ２型花岗岩,是海西晚期岩浆活动的产物,属后造山期Ａ型花岗岩。 相似文献
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Inter-regional correlation of transgressions and regressions in the Cretaceous period 总被引：1，自引：0，他引：1
T. Matsumoto 《Cretaceous Research》1980,1(4):359-373
Well investigated platforms have been selected in each continent, and the history of Cretaceous transgressions and regressions there is concisely reviewed from the available evidence. The factual records have been summarized into a diagram and the timing of the events correlated between distant as well as adjoining areas.On a global scale, major transgressions were stepwise enlarged in space and time from the Neocomian, via Aptian-Albian, to the Late Cretaceous, and the post-Cretaceous regression was very remarkable. Minor cycles of transgression-regression were not always synchronous between different areas. Some of them were, however, nearly synchronous between the areas facing the same ocean.Tectono-eustasy may have been the main cause of the phenomena of transgression-regression, but certain kinds of other tectonic movements which affected even the so-called stable platforms were also responsible for the phenomena. The combined effects of various causes may have been unusual in the Cretaceous, since it was a period of global tectonic activity. The slowing down of this activity followed by readjustments may have been the cause of the global regression at the end of the Cretaceous. 相似文献
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The Afyon stratovolcano exhibits lamprophyric rocks, emplaced as hydrovolcanic products, aphanitic lava flows and dyke intrusions, during the final stages of volcanic activity. Most of the Afyon volcanics belong to the silica-saturated alkaline suite, as potassic trachyandesites and trachytes, while the products of the latest activity are lamproitic lamprophyres (jumillite, orendite, verite, fitztroyite) and alkaline lamprophyres (campto-sannaite, sannaite, hyalo-monchiquite, analcime–monchiquite). Afyon lamprophyres exhibit LILE and Zr enrichments, related to mantle metasomatism. 相似文献
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K.Naganjaneyulu 《地学前缘(英文版)》2014,5(1):1-2
正The Precambrian shields and associated suture zones of the globe preserve important records of continental growth and destruction,the formation and closure of ocean basins,and the early evolution of the Earth in terms of tectonics,resources,and environment.They also offer critical clues on the nature and style 相似文献
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Daniel Harlov 《地学前缘(英文版)》2014,5(5):621-625
正1.Introduction This special issue of Geoscience Frontiers is a tribute volume honoring the life and career of Jacques Touret.A set of research papers has been assembled,which broadly reflect his research interests over his 50 plus year career.These papers focus on the role that fluids play during the formation and evolution of the Earth's crust.Below I provide a brief summary of the life of Jacques Touret,along with a select bibliography of his more important papers.This is then followed by a brief introduction to the papers assembled for this special issue. 相似文献
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《地学前缘(英文版)》2014,(1):139-141
正1 AIM AND SCOPE GEOSCIENCE FRONTIERS(GSF)is a bi-monthly international journal that publishes in English high quality original research articles and timely reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF aims to bridge innovative,provocative and challenging concepts and models related to various fields of research including petrology and geochemistry in understanding lithospheric architecture and mantle dynamics,global tectonics,economic geology and fuel exploration,geophysics,stratigraphy and paleontology with new 相似文献
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正The world petroleum exploration suggests that,about70%of the world’s potash resources were discovered during oil and gas exploration(Zheng et al.,2007).The Kuqa depression in the Tarim basin is abundant with petroleum exploration data,and 相似文献
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正Qarhan Salt Lake is located in the eastern part of the Qaidam Basin,which is first discovered the large potash deposit in the late 1950s.The Bieletan section is located in the west of Qarhan Salt Lake,where saline sediment 相似文献
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正With the approach of the 45th World Earth Day,China’s Ministry of Land and Resources issued the status of the Chinese geological survey and environments on 22nd April 2013.Regional geological survey in 2013 achieved new results—(why was oceanic in twice?)polar and oceanic expedition were fully completed,a national census of geography was begun,and 相似文献
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正1 Introduction The Lop Nor playa,located in the eastern end of the Tarim Basin,capped with a thick salt crust covering an area of approximately 5,500 km2(Ma 2007)that closely resembles a"Great Ear"in satellite images.Understanding the formation of the salt crust can provide important 相似文献
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In Liaoning, Hunan, Guangxi, Guizhou, Gansu, Sichuan, Anhui, Jilin and other provinces in China, there is a wide occurrence of metal quantity over 1000 tons of refractory gold ores, principally because of low gold recoveries and become ＂stay mine＂. Features of refi＇actory gold ores are： gold in micro-particles or a microscopic state that is wrapped in pyrite, presence of arsenopyrite and other sulfide minerals or disseminated in the crystal lattice of sulfide minerals; harmful impurity elements such as arsenic, carbon, mercury, antimony, copper with high content are closely related with the gold, and these elements affect the contact reaction between the gold and solvent extraction, making the recovery of the gold extraction process low. In the past 20 years, overseas countries have developed the application of the roasting oxidation method, hot acid （alkali） oxidation, bacterial oxidation and flash chlorination oxidation technology to solve this problem.Among these, biological oxidation has developed rapidly in the domestic market and gold enterprises abroad because of its low investment in infrastructure, low production costs, less environmental pollution, simple process and easy control, etc. 相似文献