长白山天池火山玻璃和长石微观特征研究   总被引：1，自引：0，他引：1       下载免费PDF全文

张秉良  洪汉净  盘晓东 《地震地质》2006,28(3):351-357

研究了长白山天池火山1000年和5000年前2次大喷发产生的浮岩和火山灰的微观特征,通过TEM-EDX和SEM-EDX分析了浮岩中的火山玻璃和长石晶屑的表面特征及风化层厚度。5000年前大喷发浮岩中的火山玻璃风化层平均厚度3·74μm,1000年前大喷发为0·98μm;5000年前大喷发浮岩中的长石表面风化溶蚀度大于1000年前大喷发物中的长石;两次大喷发浮岩中的火山玻璃风化层化学组成与火山玻璃相比富Al和Fe而Si减少。综合上述特征认为,天池火山喷发物中矿物的微观特征的差异与火山喷发年代和喷发环境有关。因此,系统研究天池火山喷发物的微观特征是十分必要的,并且具有一定的应用价值  相似文献   

利用不溶性钾矿热法生产硅钾钙镁复合肥   总被引：1，自引：0，他引：1  

薛彦辉  张桂斋  潘兆科  张维勇 《化工矿产地质》2006,28(2):105-107

以钾长石为原料和助剂白云石、氯化钠等在高温下生产硅钾钙镁肥的一种方法。并对生产原理做了进一步探讨,经过大量试验找到最佳反应条件。  相似文献   

玲珑金矿田48号矿脉蚀变钾长石稳定结构态温度估算及其找矿意义          下载免费PDF全文

张腾飞  王翠芝  吕古贤  张宝林  焦建刚  刘维民  杨桂彬  常增沛  严千豪  陈振 《地质找矿论丛》2021,36(1):29-38

胶东大开头金矿区位于玲珑断裂和破头青断裂夹持区.48号脉位于玲珑金矿田大开头矿区的西南侧,金矿床为石英脉型—蚀变岩型,围岩有二长花岗岩、钾化花岗岩、绢英岩化花岗岩、绢英岩、黄铁绢英岩、煌斑岩等.本文以玲珑金矿田大开头矿区48号脉矿体两侧钾化花岗岩中钾长石为研究对象,通过X射线粉晶衍射、电子探针等方法研究钾长石晶体结构态...  相似文献   

内蒙东七一山碱长花岗岩及其成矿作用   总被引：1，自引：0，他引：1  

王勇 《地质学报》2009,83(10):1505-1514

碱长花岗岩在国内外普遍以含多金属元素、特别是稀有金属矿化为特征,该类矿化岩体在我国多分部在华南褶皱系,而产出在内蒙西部的东七一山碱长花岗岩是我国北方地区少见的一个大型稀有金属矿化体,由于前人工作不多,对其认识较浅。本文在前人工作基础上,对其岩石学、成矿学及成岩、成矿机制等方面做了较多细致、深入的工作,表明该岩体是一个壳源岩浆直接分异演化而成的碱长花岗岩体,岩体除铷含量较高外,其中的铌－钽也有很高的利用价值,碱长花岗岩还是钨、锡、铍资源的源泉,同时派生出的大型萤石矿和文石－方解石矿产也有很高的经济价值,从而大大提高了对东七一山碱长花岗岩成岩、成矿实践和理论认识,这对在区域上扩大与这类岩体有关的找矿工作具有重要指导意义。  相似文献   

Mutual replacement reactions in alkali feldspars II: trace element partitioning and geothermometry     

Ian Parsons  Charles W. Magee  Charlotte M. Allen  J. M. G. Shelley  Martin R. Lee 《Contributions to Mineralogy and Petrology》2009,157(5):663-687

Perthitic alkali feldspar primocrysts in layered syenites in the Klokken intrusion in South Greenland, underwent dissolution–reprecipitation reactions in a circulating post-magmatic aqueous fluid at ~450°C, and are to a large degree pseudomorphs. These ‘mutual replacement’ reactions provide a perfect natural experiment with which to study trace element partitioning between sodium and potassium feldspars growing simultaneously. The reactant ‘phase’ was a cryptoperthitic feldspar consisting of low albite and low microcline in a coherent sub-μm ‘braid’ intergrowth and the product phases were ‘strain-free’ incoherent subgrains of low albite and low microcline forming microporous patch perthites on scales up to 200 μm. The driving force for the reaction was reduction of coherency strain energy. The mechanisms of this process are described in Part I. Five mixed braid perthite–patch perthite crystals were analysed for major and trace elements using laser ablation-inductively coupled plasma mass spectrometry with a 19 μm beam diameter. This gave bulk analyses of the braid texture, which were in the range Ab_73–54Or_45–27An_4.3–0.8, but could resolve Ab- and Or-rich patches in patch perthite. The major element bulk compositions of the crystals were retained during the replacement reactions. Major components in patches plot on tielines in the Ab–Or–An ternary system that pass through or very close to the parent braid perthite composition and indicate local equilibrium on the scale of a few tens of mm. Many trace elements, including REE, were lost to the fluid during the deuteric reactions, but the effect is large only for Fe and Ti. Cs, Pb and Sr were added to some crystals. Plots of log distribution coefficient D for Rb, Ba, Pb, Eu²⁺, La and Ce between Or- and Ab-rich patches against ionic radius are straight lines, assuming eightfold coordination, and to a first approximation are independent of ionic charge. K also lies on these lines, and the smaller ions Na and Ca lie close to them. The best linear fits were obtained using ionic radii for ^[8]K and ^[8]Ca, but there is ambiguity as to whether ^[7]Na or ^[5]Na is most appropriate. The linear relationship shows that the listed trace elements are in the feldspar M-site rather than in inclusions. Tl is in M although an exact D could not be obtained. The very large Cs ion partitions strongly into the Or-rich phase but its D value appears to be less than predicted by extrapolation. The near-linearity arises because partitioning is occurring between two solids into sites which have similar Young’s moduli, so that the parabolas that normally represent trace element partitioning between crystals and liquids (which have negligible shear strength) approximately cancel out. Ga and Be are in T-sites, as well as some of the Fe and Ti present, although part is in oxide inclusions. The site of Sc is unclear, but if structural it is likely to be T. Partitioning on M-sites is a potential geothermometer but because the effective size of the irregular M-site is defined by its K and (Na + Ca) contents, which are controlled by ternary solvus relationships, its calibration is not independent of conventional two-feldspar geothermometers. Trace elements may however provide a useful means of confirming that feldspar pairs are in equilibrium, and of recognising feldspar intergrowths produced by non-isochemical replacement rather than exsolution. Two-feldspar geothermometry for the ternary phases in the low-albite microcline patch perthites gives temperatures above the stability range of microcline, markedly so if a correction is made for Si–Al ordering. This is probably because current geothermometers are too sensitive to low concentrations of An in ordered Or-rich feldspars. This interpretation is supported by two-feldspar assemblages growing at known temperatures in geothermal systems and sedimentary basins. This paper and the earlier Part I are dedicated in the memory of J. V. Smith and W. L. Brown, both of whom died in 2007, in acknowledgement of their unrivalled contributions to the study of the feldspar minerals over more than half a century. An erratum to this article can be found at  相似文献   

黑龙江伊春地区晚三叠世—早侏罗世铝质A型正长-碱长花岗岩地球化学特征及其构造意义   总被引：8，自引：0，他引：8  

韩振哲  赵海玲  王盘喜  杨霄  牛延宏  赵寒冬 《岩石矿物学杂志》2009,28(2):97-108

黑龙江伊春地区晚三叠世-早侏罗世正长-碱长花岗岩的岩石学和主、微量元素及同位素分析结果表明,岩石中大多含有高温自形或锥形石英、副矿物萤石和文象结构、晶洞构造等;岩石化学特征上具有高硅、富碱和低钙镁、偏铝质-过铝质特点,稀土元素配分模式呈轻稀土元素略微富集的、缓向右倾斜而重稀土元素较为平坦、铕亏损的海鸥型,富集高场强元素(HFS)Zr和Ga,亏损Ba、Sr、Eu等;岩石中的石英包裹体均一温度为750～950℃,具有高温岩浆浅成被动就位的特征.岩石富SiO2、K2O、Al2O3,δ18O值为5.1‰～10.3‰,属正常略偏低δ18O值花岗岩类;ISr值较高、εNd值较低,暗示了其源区物质来源主要与古老下地壳变质基底物质有关,并涉及到一定程度的壳幔岩浆混合作用.综合这些特征,首次提出伊春地区晚三叠世-早侏罗世正长-碱长花岗岩属于铝质A2型花岗岩,这说明此后该地区进入了古亚洲洋最终闭合之后大陆碰撞后跨塌、伸展动力学体制的构造背景.  相似文献   

东营凹陷古近系砂岩储层成岩耗水评价   总被引：1，自引：0，他引：1  

张善文 《现代地质》2009,23(4)

成岩作用过程中会发生流体浓缩现象,对油气成藏具有重要影响。综合岩石薄片、测试分析及地质统计资料,在成岩矿物蚀变耗水作用研究的基础上,对东营凹陷古近系砂岩储层成岩耗水进行了整体评价。结果表明,东营凹陷古近系砂岩储层成岩过程中普遍发生了耗水作用,耗水反应主要为长石高岭石化,砂体总耗水量平均为383亿t。纵向上,砂岩的长石转化率和耗水量明显存在浅部和深部2个高峰区段,即1200~2000 m和2000~3500 m。平面上,东营凹陷不同区带砂岩耗水量有差异,南部缓坡带和北部陡坡带的浅部区段长石转化率和单位体积耗水量大,洼陷带的长石转化率和单位体积耗水量则以深部区段为主,由于深部区段砂体体积大,造成深部区段尤其是洼陷带砂体耗水量大。  相似文献   

牛居地区下第三系砂岩储层中自生高岭石成因分析     

车启鹏  孙洪斌  张凤莲  刘敏  李应暹 《吉林大学学报(地球科学版)》1995,(3)

在详细工作基础上，指出本区砂岩中自生高岭石主要有四种成因、即在孔隙溶液中沉淀、长石的蚀变、白云母的转化及蒙皂石的转化等，并对每种成因进行了分析，指出了主要成因机制。  相似文献   

Feldspar dissolution in the presence of organic acid anions under diagenetic conditions: an experimental study     

D.A.C. Manning  K. Gestsdttir  E.I.C. Rae 《Organic Geochemistry》1992,19(4-6)

Previous experiments to determine the aqueous solubility of lead-rich orthoclase in the presence of the ethanoic acid anion (acetate) at 150°C and 50 MPa have shown that the observed fluid compositions are essentially controlled by the presence of secondary mineral precipitates, which buffer dissolved species apart from lead. Data for lead suggest that dissolution increased with increasing fluid ethanoic acid anion content, but the ethanoic acid anion was unstable under the experimental conditions. Additional experiment have now been carried out using pure natural albite and ethanoic acid anion solutions at 150°C and 50 MPa, in which the ethanoic acid anion remains stable. The results for albite again demonstrate the influence on fluid composition of secondary mineral precipitates, but data for silica allow the rates of dissolution to be estimated. Values obtained for the dissolution rate constant increase from 1.8 × 10⁻⁷ to 5.3 × 10⁻⁷ s⁻¹ with increasing fluid ethanoic acid anion content (0.1–2.5 molal) and approximate to values for quartz and orthoclase dissolution rates for similar PT conditions, reflecting similarity in the mechanisms of dissolution of the minerals' three dimensional (alumino)silicate frameworks. However, these experiments provide no other evidence that the ethanoic acid anion enhances equilibrium solubilities of feldspars or quartz. In contrast to the results for the ethanoic acid anion, data for albite dissolution experiments in the presence of the ethanedioic acid anion (oxalate) at 150°C and 50 MPa show an inhibitionn of solubility (apart from aluminium), while data for the 2-hydroxy-1,2,3-propanetricarboxylic acid trivalent anion (citrate) show considerable enhancement of solubility for aluminium and silicon, and titanium derived from the reaction vessel. The 2-hydroxy-1,2,3-propanetricarboxylic acid trivalent anion is unstable, decaying according to first order kinetics (half life = 1.5 days). In their application to problems of diagenesis in the presence of organic acid anions, these results suggest that the ethanoic acid anion may influence feldspar dissolution by accelerating diagenetic reactions, while geologically short-lived species such as the 2-hydroxy-1,2,3-propanetricarboxylic acid trivalent anion and its decay products may dramatically enhance aluminosilicate solubility.  相似文献   

关于长石→高岭石动态形成过程的讨论     

张实  张惠芬 《矿物学报》1992,12(4):372-379,T001

在对广东几个地区高岭土、高岭石研究的基础上,从结构的观点出发,详细分析讨论了风化过程中长石→高岭石转变的动力学机制,建立了高岭石形成的长石结构动态转化模型,并以此解释了高岭土矿床以及高岭石的某些特征和现象。  相似文献