丹凤群斜长角闪岩中角闪石的环带及变质作用

在丹凤群中,部分斜长角闪岩含有由阳起石内核和镁普通角闪石外环组成的环带角闪石。外环形成于主变质期,而内核是早期变质矿物的残余。早期变质作用属低压相系的斜长石-阳起石相环境,发生在丹凤群形成之初;而主期变质发生在加里东晚期的中压相系的角闪岩相。大约在海西—印支期后又出现了伴随韧性剪切作用的退变质现象。早期变质和主期变质作用可能分别与秦岭造山带的裂谷作用和裂谷闭合过程有关。     

辽北太古宙岩石形成的构造背景与地壳演化

辽北太古宙花岗质岩石及层状变质岩系的研究表明,它们均形成于太古代的大陆边缘环境。早太古代以前(大于3000Ma),本区已发育了成分不均匀的原始地壳,后期表壳岩系沉积在这种地壳的裂谷当中并发生了麻粒岩相变质作用;大约在2800—2500Ma,发生大规模花岗质岩石侵位,形成英云闪长岩—奥长花岗岩的结晶分异趋势;太古代晚期,由于地壳的增生迥返,先存岩石发生角闪岩相变质作用和深熔作用,形成钾长花岗岩的定位,并形成钙碱性的演化趋势。在整个太古宙地质演化过程中变形作用一直贯穿始终。     

山东省昌邑市南任铁矿地质特征及成因初探

南任铁矿床位于莱州-安丘铁成矿带西北部,对其矿床成因认识存在较多争议。矿区内地层广布,构造、岩浆岩不发育。铁矿体呈透镜状产于滹沱纪粉子山群小宋组的底部层位,无穿插或交代围岩现象;围岩蚀变以蛇纹石化、绿泥石化为主,愈近矿体矿化蚀变愈强。矿石矿物以磁铁矿为主,少量黄铁矿、黄铜矿;脉石矿物主要为蛇纹石、绿泥石。矿石的结构构造主要为浸染状构造,半自形—他形粒状结构。岩矿石稀土元素含量表明磁铁矿主要为火山深成岩浆结晶分异形成,部分与火山沉积作用有关;磁铁矿化学成分特征也反映了这一点,综合认为其成因可能属海相火山岩型之火山岩浆-热液和火山沉积复合类型。在此基础上,总结了莱州-安丘铁成矿带上不同成因铁矿床的分布规律,为今后该地区铁矿勘查指明了方向。     

广西大化县透闪石玉的产地特征

广西河池市大化瑶族自治县发现了透闪石玉矿床,研究程度较低,但是该产区玉石在市场上却占有不小份额,对该区透闪石玉的宝石学特征及其产地属性进行系统研究具有重要意义。通过常规测试、拉曼光谱（RAMAN）、X射线粉晶衍射（XRD）、电感耦合等离子质谱（ICP-MS）、激光诱导击穿光谱（LIBS）等测试,研究该区透闪石玉的包体特征、谱学特征、结构特征和成分特征,来解读本地区透闪石玉的产地属性。研究结果显示:大化透闪石玉的主要矿物成分SiO₂、MgO和CaO较为稳定,次要矿物成分MnO,FeO,TiO₂的变异系数相对较大,样品的微量元素B,Cr,Zn,Sr含量较高,V,Co,Ni的含量相对较低,Fe2+/（Mg2++Fe2+）平均值为0.03,显示主要矿物为透闪石,说明本区透闪石玉为镁质大理岩受到接触交代变质作用而形成,低铁,高钙为特征;从样品所含有的稀土元素来看,该矿区的透闪石玉稀土元素总量∑REE偏低,轻重稀土元素分异不明显,属于轻稀土元素富集型,稀土配分模式属于右倾型,比较平坦,Eu负异常,有明显的Ce负异常;透闪石玉结晶度平均值为0.963,大于新疆透闪石玉的结晶度平均值0.843,与青海的0.96相近,这反映出大化透闪石玉的结晶程度较高,晶体颗粒相对较大,结晶环境良好;透闪石玉中铍/硅LIBS强度比（I_Be/I_Si）为:中国广西大化透闪石玉为0,中国新疆透闪石玉0.003~0.008,中国青海透闪石玉为0,中国辽宁透闪石玉为0.004~0.006,韩国透闪石玉为0.1~0.16,俄罗斯透闪石玉为0.03~0.05。研究结果与其他产地的比对可为溯源提供参考。      

鲁西太古代徂徠山杂岩体花岗质岩石成因探讨

鲁西太古代徂徕山杂岩体主要由片麻状花岗岩和钾长花岗岩构成,此外尚发育少量小规模的中粗粒、细粒闪长岩。本文着重讨论花岗质岩石的成因。徂徕山杂岩体岩石地球化学研究表明,片麻状花岗岩为深源(下地壳)花岗质岩浆侵位结晶的产物;钾长花岗岩是片麻状花岗岩在区域变质作用过程中部分熔融形成的,两者具有密切的成因联系。     

南方结晶岩区天然矿泉水水文地球化学过程研究——以广东省中山市为例

广东省中山市结晶岩地区富含优质的低钠低矿化度偏硅酸型矿泉水。本文基于区域地质背景及主要水体的水化学测试结果,对该地区的天然矿泉水开展了水文地球化学过程研究,包括水文地球化学特征分析、主要成分来源分析、矿泉水年龄分析以及水化学的反向模拟等。对比分析结果显示:结晶岩区的矿泉水与普通民井水和河湖水等具有近似的形成条件,但硫酸根、氯离子和镁离子浓度偏低;矿泉水与地热水的形成条件则存在较大的差异,地热水与海水存在明显的混合作用。而矿泉水主要组分的相关性分析和反向模拟结果表明:矿泉水化学组分的来源除了与含水系统的造岩矿物密切相关外,还与母岩风化或交代蚀变矿物密切相关,在水循环过程中溶滤了碳酸盐、硫酸盐和岩盐等矿物,矿泉水特征组分偏硅酸主要源于斜长石水解作用,与二氧化硅相关矿物关系不大。在矿泉水的形成过程中,碳酸平衡体系起着重要作用,水化学的形成需要有充足的二氧化碳气体,导致此类微矿化水多数呈弱酸性反应。本研究为进一步深入研究南方结晶岩地区微矿化水的形成机制提供了参考依据,对类似的矿泉水资源勘查评价具有一定的指导意义。     

淄博市淄川区采空塌陷现状与治理对策分析

淄川区矿产资源丰富,伴生、共生矿较多,矿产资源组合好,煤炭、耐火材料、紫砂、陶土、铝土矿、石灰石、铁矿石、石英等储量大,分布广。矿产资源的长期开采引发的地表采空塌陷面积约60km2,危及到人民生命财产安全并对农田造成破坏。该文对淄川区采空塌陷现状及发展趋势进行了分析并提出了治理对策。     

Gold Deposition by Boiling or Cooling Without Boiling: Genesis of the Sangchon Gold Deposits, Hadong Area, South Korea

In order to understand the mechanism(s) of gold precipitation in the anorthosite- hosted Sangchon gold deposits in the Hadong area, Korea, chemical speciation and reaction path calculations were accomplished by geochemical modeling.The modeling consisted of three- step procedures: reaction with anorthosite, then the simple cooling of the reacted fluid,and finally the boiling of metalliferous fluid. The principal vein minerals of the Sangchon deposits consist of quartz, sericite,kaolinite, pyrite, galena, chalcopyrite, sphalerite and acanthite. The sulfide mineralization is typically zoned from pyrite (preferentially at vein margins) to galena and sphalerite (toward vein center). Electrum is intimately associated with pyrite + chalcopyrite and sphalerite. By comparing the results of modeling with the observed mineral assemblages and paragenesis,the most appropriate evolution path of ore fluids was suggested as follow: reaction of a single fluid with anorthosite at 300℃,then the isobaric cooling of the fluid at temperatures from 2500° to 100℃3 , and then the boiling and cooling of the fluid due to the decrease of pressure and temperature. Calculations also show that all of the observed alteration minerals formed due to fluid - anorthosite interaction at early period, whereas most of sulfides and electrum were precipitated mainly due to cooling.The abundance of gold in veins depends critically on the ratio of total base metals plus iron to sulfide in the aqueous phase,because gold is transported as Au(HS)2- whose solubility is very sensitive to the sulfide activity. Our results of geochemical modeling generally fit to the observed mineral assemblages and mineral composition, indicating the usefulness of numerical simulation for elucidating the genesis of gold deposits.     

论合理开发利用舞阳铁矿的几个问题

舞阳铁矿系指位于河南省平顶山市所辖舞钢市区内含铁矿大小共计１２处的一群铁矿区,总储量占河南省铁矿探明储量的５３％,主要有铁山（含铁古坑、铁山庙）、八台（含赵案庄、王道行）及经山寺等大、中型铁矿区。矿床类型主要为沉积变质型,次为岩浆型;区内铁矿品位不高,主要矿物为磁铁矿及部分赤铁矿。在阐述资源概况及建矿历程的基础上,对如何合理开发利用舞阳铁矿,重点就矿区的规划,红矿的利用,磷、铀的综合利用,矿产开发对环境的影响,以及矿山开发管理等问题进行了较为详细的论述,提出了相应的对策建议     

Shock metamorphism in meteorites

Shock metamorphism resulting from hypervelocity collisions between planetary bodies, is a fundamental processes in the solar system. The term "shock metamorphism" is used to describe all changes in rocks and minerals resulting from the passage of shock waves. Most meteorites have experienced collisions and have a record of shock metamorphism, which includes brecciation, deformation, phase transformation, local melting and crystallization. The key to reading this record is to use the shock features to estimate the pressure and duration of shock event. In this paper, the history of the study of shock metamorphism is reviewed; basic knowledge of shock physics is discussed; recent 10 years' studies of shock-induced melt veins are summarized; and finally a short note to the shock metamorphism in general is given.     

烟台北部古元古代芝罘群变形变质作用及演化

在分析烟台北部芝罘群主要变质岩类的变质矿物共生组合、变质相系及构造岩等特征的基础上,对该群变形、变质作用及演化特征进行了探讨.认为该区芝罘群曾经历1期韧性变形作用和4期变质作用(古元古代高角闪岩相、中元古代早期低角闪岩相、中元古代晚期高绿片岩相及新元古代低绿片岩相变质作用).     

胶东牟平—乳山地区花岗岩副矿物特征及其成因

本文论述了牟平—乳山地区花岗岩的岩石学特征,副矿物组合特征,尤其是锆石特征,副矿物的化学成分与微量元素及稀土元素组合特征,并在此基础上探讨了花岗岩的成因。本区花岗岩的成因是复杂的,既有花岗岩化作用(交代作用)和深熔作用形成的花岗岩,又有岩浆分异结晶作用的产物。     

烟台北部古元古代芝罘群变形变质作用及演化

在分析烟台北部芝罘群主要变质岩类的变质矿物共生组合、变质相系及构造岩等特征的基础上 ,对该群变形、变质作用及演化特征进行了探讨。认为该区芝罘群曾经历 1期韧性变形作用和 4期变质作用 (古元古代高角闪岩相、中元古代早期低角闪岩相、中元古代晚期高绿片岩相及新元古代低绿片岩相变质作用 )。     

不同国别进口铁矿石矿物学特征分析: 来自显微组分和元素分析的约束

我国是铁矿石资源进口大国,通过分析不同产地进口铁矿石的矿物学特征,可以为铁矿石原产地分析及固体废物属性鉴定提供参考依据。以11个常见进口国一级铁矿石样品为研究对象,综合运用偏光显微镜、X射线荧光光谱法（XRF）以及黄铁矿、磁铁矿LA-ICP-MS微量元素分析等方法,查明了各国铁矿石的元素组成和矿物组合特征,探究了不同产地铁矿石形成的地质环境。X射线荧光光谱分析表明铁矿石样品主要元素为Fe,O,其次为Si,Ca,Al,Mn,Tb,Ti,Mg,P,S,不同国别铁矿石元素含量存在差异。偏光显微镜光片鉴定表明铁矿石样品不仅矿物类型上存在差异,而且在副矿物种类和含量、结构构造等方面存在差别,这些差异性特征可以作为铁矿石产地判别的依据。磁铁矿微区原位微量元素的成因类型判别结果显示,澳大利亚磁铁矿主要为BIF建造型,而缅甸、老挝为矽卡岩型。采用多种技术表征不同产地铁矿石样品的矿物组成、元素含量、矿相组成、矿物形成环境的差异性,揭示了不同产地铁矿石样品的矿物学特征,对进口铁矿石质量的识别、管控和产地溯源具有重要意义。      

Petrology of ureilites from Grove Mountains, Antarctica：Constraints on the origins

Ureilites are a common group of achondrites with a high abundance of carbon. They probably have a genetic relationship with chondrites, hence provide an insight into origin and evolution of terrestrial planets. A new meteorite-rich region, Grove Mountains (GRV), was found by the Chinese Antarctic Research Expedition, with discovery of 9834 meteorites. Of 2433 meteorites classified, 9 ureilites have been identified. In this paper, we report petrography of 6 of these ureilites. Four ureilites contain graphite and exhibit triangle conjunction and common reduced margins of olivine. GRV 052382 probably experienced heavy shock metamorphism followed by fast cooling, as indicated by mosaic texture or fine-grained granular texture of olivine. GRV 022931 was highly reduced of these ureilites, with olivine as isolated grains in abundant carbonaceous matrix. All 9 ureilites are monomict, and are classified into subtype II (with medium FeO content, Fa15-18) and subtype I (with high FeO content, Fa>18) based on compositions of the cores of olivine. The diverse mineral compositions and petrography of these ureilites suggest that they are not paired and reveal a multi-event history of the parent body. Partial melting of the parent body produced carbon-rich magma, followed by crystallization of graphite and silicates. Later, graphite was partially inverted to diamond by shock events. Reburial of the shocked debris experienced various degree of thermal metamorphism. Finally, these rocks were excavated from the parent asteroid and ejected into Earth-cross orbit by another impact event.     

海州—大悟混合岩穹窿地质及成矿作用

文章是在研究海州－大悟含磷岩系及其磷矿底板岩石中不同类型混合岩的岩石学、地球化学的基础上，探讨了变质－深熔过程中稀土元素的活动性状。混合岩穹窿由变沉积岩、混合岩及混合花岗片麻岩组成。变沉积岩、混合岩及混合花岗片麻岩在空间上的密切共生关系，揭示了沉积物经历了变质分异、混合岩化和部分熔融作用改造成花岗质岩石的过程。穹窿具有明显的分带性，从穹窿外向中心，由变质岩带、混合岩带向混合花岗片麻岩带变化，表明了变质反应顺序及混合花岗岩化交代的关系。在变质、混合岩化及部分熔融作用形成混合岩穹窿过程中，磷质发生了运移，在穹窿变质岩与混合岩接触带发生了交代结晶与重结晶作用。在穹窿变质岩带，揉流褶皱成矿作用十分明显     

鲁山棚沟金矿床包裹体特征及找矿意义

棚沟金矿床赋存于华北古陆块南缘前寒武纪花岗岩中，在空间上受区域韧性剪切带中的燕山末期花岗斑岩控制。根据矿床地质特点判断属中低温热液型金矿。通过岩石矿物组合及包裹体组成、性质、同位素等测试，确定成矿物质来源于围岩，成矿流体来源于变质水且有岩浆水与雨水的混入。通过电子探针测定的岩矿组分，计算围岩成岩及变质温度，以及成矿温度、压力和沉淀条件，认为金矿床的成矿作用，主要表现为减压环境中的岩浆热液充填和交代蚀变，以及热液的泡腾作用。从找矿标志角度确定富ＣＯ２的泡腾包裹体群、液相高硫富ＨＣＯ－３、气相高ＣＯ２和高ＣＯ２／Ｈ２Ｏ比值等参数是寻找此类金矿的重要标志     

Mineral Components and Anti-oxidant Activities of Tropical Seaweeds

Seaweeds are known to hold substances of high nutritional value; they are the richest resources of minerals important to the biochemical reactions in the human body. Seaweeds also hold non-nutrient compounds like dietary fiber and polyphenols. However, there is not enough information on the mineral compounds of tropical seaweeds. Also we are interested in the antioxidant activities of seaweeds, especially those in the tropical area. In this study, Indonesian green, brown and red algae were used as experimental materials with their mineral components analyzed by using an atomic absorption spectrophotometer. The catechins and flavonoids of these seaweeds were extracted with methanol and analyzed by high performance liquid chromatography （HPLC） ; the anti-oxidant activities of these seaweeds were evaluated in a fish oil emulsion system. The mineral components of tropical seaweeds are dominated by calcium, potassium and sodium, as well as small amounts of copper, iron and zinc. A green alga usually contains epigallocatechin, gallocatechin, epigallocatechin gallate and catechin. However, catechin and its isomers are not found in some green and red algae. In the presence of a ferrous ion catalyst, all the methanol extracts from the seaweeds show significantly lower peroxide values of the emulsion than the control, and that of a green alga shows the strongest anti-oxidant extract of this alga, which is significantly different from activity. The highest chelation on ferrous ions is also found in the the other methanol extracts in both 3 and 24 h incubations.     

GRV 051523： A new eucrite

Grove Mountains (GRV) 051523 is a newly identified eucrite, consisting mainly of coarse-grained pyroxene (62.9 vol%) and plagioclase (34.2 vol%), with less abundant opaque minerals (2.7 vol%), minor silica and tiny FeO-rich olivine (Fa75). Coarse-grained pyroxenes show exsolution of augite lamellae in pigeonite or vice versa. Width of most exsolution lamellae in pyroxenes is 1-3 μm. Opaque minerals are mainly chromite, ilmenite and sulfides. The meteorite was heavily shocked, as indicated by breccias and melt veins. Coarse-grained pyroxenes commonly contain abundant tiny or needle-like chromite inclusions with orientation, probably due to heavy shock events. Pyroxenes in various petrographic occurrences exhibit highly homogeneous compositions, indicating that GRV 051523 experienced intense thermal metamorphism in the parent asteroid 4 Vesta. GRV 051523 is classified as Type 5-6. This new eucrite will have additional constraints on chemical composition, magmatic differentiation, multi-stage shock and thermal history of Vesta.     

山东省齐河——禹城地区矽卡岩型铁矿磁铁矿元素地球化学特征及其对成矿作用的指示意义

山东省齐河-禹城地区在黄河北厚覆盖区,有明显的航磁异常和重力异常,通过系统的地质勘探工作,在深部揭露了多处铁矿床,为系统掌握研究区磁铁矿成因机制,服务于基础地质和矿产资源调查,利用EMPA对磁铁矿进行主量元素分析,以确定其成因及成矿环境特征。其中TiO2-Al2O3-MgO和(Ca+Al+Mn)-(Ti+V)成因判别图解表明,磁铁矿属于岩浆热液-矽卡岩型成因类型;FeO(全铁)与SiO2,Al2O3,MgO元素的线性变化关系指示Fe在碱性环境富集成矿;结合V2O3,Cr2O3,TiO2,Ga2O3,SnO2等氧化物对成矿环境温度和氧逸度的指示意义,综合分析认为,成矿作用主要发生在岩浆结晶分异晚期,成矿环境具有高氧逸度、低温、偏碱性的特点。