铊-锗-硫三元素相平衡的实验研究

本文用抽真空石英管在干体系中对Tl-Ge-S三元系在300℃等温切面相关系和沿Tl_2-GeS_2及Tl_2-GeS变温切面假二元系相平衡进行了实验研究。 Tl-Ge-S三元系在300℃为三个液相区与三个二元相、八个三元相(包括三个固溶体)和十四个两相区、二十四个三相区稳定共存的复杂相关系。本实验首次合成了三个三元相(Tl_2Ge_(1-x)S_2、Tl_5Ge_(13)S_(24)、TlGe_3S_5)和三个固溶体相,即S·S·a(Tl_2~+Ge~(4+)S_3～Tl_2~+Ge_2~(2+)S_3)、S·S·b(Tl~+Ge_(0.5)~(2+)Ge_(0.5)~(4+)S_2～Tl~+Ge_3~(2+)S_4),S·S·c(Tl~+Ge_2~(2+)S_3～Tl_2~+Ge_5S_6)。     

含钾水盐体系介稳相关系研究

针对西藏扎布耶盐湖卤水组成,采用等温蒸发法分别研究了含钾四元体系Na+,K+//Cl-,B4O27--H2O308.15K、五元体系K+//Cl-,CO23-,SO42-,B4O72--H2O273.15K下的介稳相关系。分别测定了上述体系308.15K、273.15K时介稳平衡液相组成及密度、pH值。根据实验数据绘制了相应的介稳相图、水图。结果表明,本文研究的两个体系均为简单共饱型,无复盐和固溶体生成。其中,四元体系介稳相图由2个共饱点,5条单变量曲线,4个结晶区组成。平衡固相分别为Na2B4O7.10H2O、K2B4O7.4H2O、NaCl和KCl。对比四元体系308.15K和273.15K下的介稳相图发现,平衡固相盐的种类及结晶形式均没有发生变化,但结晶区大小产生变化:在308.15K下,Na2B4O7.10H2O结晶区变小,K2B4O7.4H2O结晶区变大。五元体系投影图中有1个共饱点、3条单变量曲线和3个结晶相区。结晶相区分别为K2CO3.3/2H2O、K2SO4和KCl。K2CO3.3/2H2O结晶区面积最小,K2SO4结晶区面积最大。K2CO3对KCl有较强的盐析作用。     

新疆阿尔泰造山带低压变质作用相平衡研究

通过对阿尔泰造山带低压型变质序列中典型泥质岩石进行详细的岩相学及相平衡研究,获得黑云母带变质作用的温度为445～550℃和压力为0.2～0.6 GPa;石榴石带为480～566℃、0.54±0.22 GPa;十字石带601±20℃、0.8±0.25GPa;十字石-红柱石带540±20℃、0.32±0.05 GPa,而632.4℃、0.785 GPa这个值不是红柱石的稳定范围,这可能是其早期中压变质作用条件;矽线石带为640℃、0.43 GPa左右,由于石榴石中有蓝晶石包体,因此其早期也可能经历中压条件的变质;堇青石-矽线石带740～800℃、0.4～0.7 GPa。阿尔泰造山带低压变质序列不是一个正常的变质序列,其野外变质梯度呈现“Z”字型特征。阿尔泰造山带低压变质作用可能形成于早期中压变质岩的挤压抬升和以此相关的大量花岗岩侵入的构造环境中。     

甲烷水合物在AlCl3溶液中的相平衡条件

利用可视法测定了甲烷水合物在AlCl₃溶液中的三相平衡(甲烷水合物-AlCl₃液相-甲烷气相)条件.AlCl₃溶液中甲烷水合物的生成压力为4.040～8.382 MPa,温度为272.15～278.15 MPa.对相同摩尔浓度的AlCl₃和KCl溶液中甲烷水合物生成条件的抑制作用进行了讨论.并将实验结果与前人的研究数据进行了对比,通过统计分析得到一计算甲烷水合物相平衡压力与温度的经验公式,经计算所得结果与实验数据一致.研究认为AlCl₃溶液可以作为一种良好的抑制剂用于油气工业的输送管道中。     

Phase Equilibria of Salt-water Systems Containing Magnesium and Borate Ions

正1 Introduction A salt lake is a naturally occurring complex body of water and salt interaction.More than 700 salt lakes are widely distributed in the area of the Qinghai-Tibet Plateau.Most of the salt lakes are famous for their abundance of lithium,potassium,magnesium,and boron resources.It is     

胶北地块高压与低压泥质麻粒岩的相平衡关系与p-T演化轨迹

利用最新的内洽性热力学数据库和THERMOCALC3.21程序对胶北地块高压与低压泥质麻粒岩的相平衡关系进行了定量分析。计算了胶北地块高压泥质麻粒岩、低压泥质麻粒岩和夕线石榴黑云片岩等代表性富铝岩石KFMASH(K2O-FeO-MgO-Al2O3-SiO2-H2O)体系的p-T视剖面图,再现了这些岩石随温压条件变化可能出现的各种矿物组合与矿物成分变化,发现原岩成分不同的变质岩石,尽管变质演化过程有所差异,但在麻粒岩相变质条件下所形成的矿物组合一致。通过计算泥质岩石在高压(p=1.0GPa)和低压(p=0.5GPa)条件下的T-X视剖面图,发现极度富铁、贫镁的岩石,在高压麻粒岩相条件下并不会生成含蓝晶石的特征矿物组合,在低压麻粒岩相条件下也不会生成含堇青石的特征矿物组合。将样品实际观测结果与p-T视剖面图的计算结果对比,确定胶北地块高压泥质麻粒岩变质峰期的温压条件为830~860℃,1.25~1.4GPa,峰期后呈现顺时针样式的p-T演化轨迹,反映陆壳先碰撞增厚、后又快速减薄的地质动力学过程;确定胶北地块低压泥质麻粒岩变质峰期的温压条件为790~820℃,0.62~0.68GPa,峰期后呈现近等压冷却的p-T演化轨迹。     

A ternary solid solution model for omphacite and its application to geothermobarometry of eclogites from the Middle Adula nappe (Central Alps, Switzerland)

A ternary solid solution model for omphacite with the end-members jadeite (NaAlSi₂O₆), diopside (CaMgSi₂O₆) and hedenbergite (CaFeSi₂O₆) was derived from experimental data from the literature. The subregular solution model, fitted by linear programming, is best suited to omphacites with very little aegirine component in common eclogites. Applying this solution model to the calculation of equilibrium phase diagrams of eclogites from the Adula nappe (Central Alps, Switzerland) results in large stability fields for common eclogite assemblages (garnet+omphacite+quartz+H₂O±kyanite). Within this field the compositions of garnet and omphacite show very little variation. A precise determination of the peak-pressure and temperature is not possible. The occurrence of amphibole, overgrowing the peak-pressure assemblage in fresh eclogite, suggests retrograde re-equilibration, still under eclogite facies conditions. The computation of isopleths for garnet and pyroxene end-members allows the estimation of the pressure and temperature conditions of this re-equilibration event (19–21  kbar, c .  700 °C).     

内蒙古中部印支期强过铝质花岗岩的相平衡约束及动力学背景

岩石相平衡分析表明，内蒙古中部沿华北地台北缘分布的印支期(T3)后碰撞强过铝质花岗岩的源岩为含泥质成分较高的岩石，是在小于1．5GPa(约50km)条件下，由源岩中白云母及黑云母脱水部分熔融形成的，形成温度低于黑云母消失的上限温度，熔融残留物有斜长石、石榴子石和辉石。本区强过铝质花岗岩的CaO／Na2O比值(0.09～0．58)说明，其源岩中既有泥质岩，又有砂岩，与岩石相平衡分析的结果相一致；Al2O3/TiO2比值(53．78～413．94)表明，本区的强过铝质花岗岩为高温类型和高压类型之间的一种过渡类型。     

Stable Phase Equilibrium of the Aqueous Ternary System Li~+//Cl~-,borate- H_2O at 348 K

正The Sichuan Basin,with an area of about 20×104 km2,is situated at 102.5°~110°E and 27.67°~32.67°N.The underground brine resources in Sichuan basin are a type of comprehensive liquid mineral resource.Pingluo     

Subsolidus Phase Relations in the System MgO-SiO_2-Cr-O and Thermodynamic Properties of Related Cr~(2+)-Containing End-members

Subsolidus phase relations have been determined in the systems SiO2-Cr-O and MgO-SiO2-Cr-O in equilibrium with metallic Cr, at 1100 to 1500℃ and 0 to 2.88 GPa. The results show that there are no ternary phases in the SiO2-Cr-O system at these conditions, i.e., only the assemblage eskolaite-Cr-metal-quartz (or tridymite) is found. In the MgO-containing system, however, extensive substitution of Cr2+ for Mg is observed in (Mg, Cr2+)2SiO4 olivine, (Mg, Cr2+)2Si2O6 pyroxene, and (Mg, Cr2+)Cr2O4 spinel. Cr3+ levels in olivine and pyroxene are below detection limits. The pyroxene is orthohombic at XCrPx2+ < 0.2, monoclinic at higher XCrPx2+ . Thestructure of the spinels becomes tetragonally distorted at XCr2+Sp >0.2. The experimental datahave been fitted to a thermodynamic model, and the authors obtained the mixing parameter (W) of Mg-Cr2+ in olivine, pyroxene and spinel, and the relation between temperatures and free energies of formation for the end-members: Cr2+-olivine (Cr2SiO4), Cr2+-pyroxene (Cr2Si2O6)     

大别山南部高压-超高压变质地体中云母片岩和片麻岩的相平衡研究

对于大别山高压一超高压变质带中大面积出露的云母片岩和片麻岩的变质条件和演化历史有不同的认识：如中低压绿帘角闪岩相，高压角闪岩相和超高压榴辉岩相。通过对大别山南部超高压榴辉岩区、高压榴辉岩区和宿松变质杂岩带中的云母片岩和片麻岩进行详细的岩相学及相平衡研究表明：它们的变质条件分别为610℃～690℃，1．2～1．4GPa；590～600℃、1．3～1．5GPa；520～590℃，0．9～1．4GPa，相当于高压绿帘角闪岩相、高压角闪岩相与榴辉岩相之间的过渡。依据超高压榴辉岩区绿帘石黑云片麻岩中的石榴石环带特征推测，它们很可能经过超高压变质阶段。现有矿物组合记录了抬升阶段的条件。但是高压榴辉岩区的石榴石绿帘石二云片麻岩和宿松变质杂岩带中石榴石云母片岩中的石榴石环带特征表明，其现有矿物组合记录了变质峰期条件，不应该经历更高压变质阶段。在KFMASH体系的PT视剖面图上计算多硅白云母Si含量等值线表明，在多数矿物组合中白云母的Si含量可作为地质压力计，但Si等值线的斜率受到矿物组合的控制。     

Phase Equilibria of Hornblende-Bearing Eclogite in the Western Dabie Mountain,Central China

The high-pressure (HP) eclogite in the western Dabie Mountain encloses numerous hornblendes,mostly barroisite.Opinions on the peak metamorphic P-T condition,PT path and mineral paragenesis of it are still in dispute.Generally,HP eclogite involves garnet,omphacite, hornblendes and quartz,with or without glaucophane,zoisite and phengite.The garnet has compositional zoning with X_(Mg) increase,X_(Ca) and X_(Mn) decrease from core to rim,which indicates a progressive metamorphism.The phase equilibria of the ...     

拉萨地块松多榴辉岩的变质演化过程:NCKMnFMASHTO体系中的相平衡关系

拉萨地块松多榴辉岩主要矿物组合为石榴子石、绿辉石、角闪石、多硅白云母、绿帘石、金红石。石榴子石环带不明显,核部成分均一,从核部到边部,镁铝榴石和钙铝榴石含量降低,可能分别记录了榴辉岩峰期及退变质过程信息。绿辉石显示微弱的成分环带,硬玉含量从核部到边部略有升高,部分绿辉石边部发育韭闪石退变质边,反映了在减压过程中外来流体进入体系的过程。多硅白云母具有高的Si含量(3.5~3.6),其中石榴石包体中的多硅白云母相对基质中的白云母有更高的Si值。本文利用Thermocalc变质相平衡模拟软件,结合详细岩相学观察,在NCKMn FMASHTO体系下,模拟松多含多硅白云母榴辉岩的变质演化过程。其中,榴辉岩峰期矿物组合为g+o+law+phn+ru,石榴石核部最大镁铝榴石值和石榴子石包体中多硅白云母最大Si值确定的榴辉岩峰期温压条件约为620℃,32×105Pa,榴辉岩经历了近等温降压的退变质过程。相平衡模拟结果表明拉萨地块松多榴辉岩经历了超高压变质作用过程,并经历了相对快速的折返过程到中部地壳层次。     

Phase equilibria and metamorphic evolution of glaucophane‐bearing UHP eclogites from the Western Dabieshan Terrane,Central China

Glaucophane‐bearing ultrahigh pressure (UHP) eclogites from the western Dabieshan terrane consist of garnet, omphacite, glaucophane, kyanite, epidote, phengite, quartz/coesite and rutile with or without talc and paragonite. Some garnet porphyroblasts exhibit a core–mantle zoning profile with slight increase in pyrope content and minor or slight decrease in grossular and a mantle–rim zoning profile characterized by a pronounced increase in pyrope and rapid decrease in grossular. Omphacite is usually zoned with a core–rim decrease in j(o) [=Na/(Ca + Na)]. Glaucophane occurs as porphyroblasts in some samples and contains inclusions of garnet, omphacite and epidote. Pseudosections calculated in the NCKMnFMASHO system for five representative samples, combined with petrographic observations suggest that the UHP eclogites record four stages of metamorphism. (i) The prograde stage, on the basis of modelling of garnet zoning and inclusions in garnet, involves P–T vectors dominated by heating with a slight increase in pressure, suggesting an early slow subduction process, and P–T vectors dominated by a pronounced increase in pressure and slight heating, pointing to a late fast subduction process. The prograde metamorphism is predominated by dehydration of glaucophane and, to a lesser extent, chlorite, epidote and paragonite, releasing ～27 wt% water that was bound in the hydrous minerals. (ii) The peak stage is represented by garnet rim compositions with maximum pyrope and minimum grossular contents, and P–T conditions of 28.2–31.8 kbar and 605–613 °C, with the modelled peak‐stage mineral assemblage mostly involving garnet + omphacite + lawsonite + talc + phengite + coesite ± glaucophane ± kyanite. (iii) The early decompression stage is characterized by dehydration of lawsonite, releasing ～70–90 wt% water bound in the peak mineral assemblages, which results in the growth of glaucophane, j(o) decrease in omphacite and formation of epidote. And, (iv) The late retrograde stage is characterized by the mineral assemblage of hornblendic amphibole + epidote + albite/oligoclase + quartz developed in the margins or strongly foliated domains of eclogite blocks due to fluid infiltration at P–T conditions of 5–10 kbar and 500–580 °C. The proposed metamorphic stages for the UHP eclogites are consistent with the petrological observations, but considerably different from those presented in the previous studies.     

A study on the mixing proportion in groundwater samples by using Piper diagram and Phreeqc model

Piper (1944) diagram has been the basis for several important interpretations of the hydrogeochemical data. As seen in this diagram, most natural waters contain relatively few dissolved constituents, with cations (metals or bases) and anions (acid radicles) in chemical equilibrium with one another. Apart from the facies representation, the composition of the mixed sample can be identified in terms of the composition of the parental solution. To bring out this advantage of the Piper diagram, a study was conducted in the Kalpakkam region of Tamilnadu, South India. By taking the geology and water table into consideration, two sample locations were selected as parent solution and third one as the mixture sample. All three samples were analyzed for calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), chloride (Cl), sulphate (SO4) and phosphate (PO4) by Ion Chromatograph (Metrohm IC 861). HCO3 was determined by volumetric titration. The Piper diagram shows that parent solutions clustered towards Na-Mg-Ca-HCO3-Cl and Na-HCO3 facies, and the mixing sample belongs to Na-Mg-HCO3 facies. Phreeqc interac-tive (Ver 2.8) along with the original composition of the mixture sample was used to correlate the mixing proportion identified by the Piper diagram.     

Phase Equilibria in the Ternary Systems KBr–K2B4O7–H2O and KCl–K2B4O7–H2O at 373 K

According to the compositions of the underground gasfield brines in the west of Sichuan Basin,the phase equilibria in the ternary systems KBr-K2B4O7-H2O and KCl-K2B4O7-H2O at 373 K were studied using the isothermal dissolution equilibrium method.The solubilities of salts and the densities of saturated solutions in these ternary systems were determined.Using the experimental data,phase diagrams and density-composition diagrams were constructed.The two phase diagrams were simple co-saturation type,each having an invariant point,two univariant curves and two crystallization regions.The equilibrium solid phases in the ternary system KBr-K2B4O7-H2O are potassium bromide （KBr） and potassium tetraborate tetrahydrate （K2B4O7·4H2O）,and those in the ternary system KCl-K2B4O7-H2O are potassium chloride （KCl） and potassium tetraborate tetrahydrate （K2B4O7·4H2O）.Comparisons of the phase diagrams of the two systems at different temperatures show that there is no change in the crystallization phases,but there are changes in the size of the crystallization regions.As temperature increases,the solubility of K2B4O7·4H2O increases rapidly,so the crystallization field of K2B4O7·4H2O becomes smaller.     

变质玄武岩体系相平衡及矿物 熔体微量元素分配：限定TTG/埃达克岩形成条件和大陆壳生长模型

埃达克质岩石是高Na、Al和Sr、低Y和HREE以及Nb、Ta亏损的钠质花岗质岩石,奥长花岗岩-英云闪长岩-花岗闪长岩(TTG)是早期(太古宙)大陆壳主要组分,成分与埃达克质岩石相似,这些成分独特的岩石总体上认为是俯冲洋壳、下地壳和拆沉的下地壳中变质玄武岩部分熔融的产物。文中综述我们近年来在变质玄武岩体系相平衡和矿物-熔体微量元素分配实验研究成果:相平衡实验和熔体微量元素特征研究表明,变质玄武岩部分熔融过程中金红石是导致TTG/埃达克岩浆Nb、Ta亏损的必要残留矿物,从而否定了前人“TTG由无金红石的角闪岩熔融产生”的观点;证实金红石仅仅在压力1.5GPa以上才能稳定存在,从而限定TTG/埃达克岩熔体必定产生在大约50km以上,表明TTG/埃达克岩是在相对较深的含金红石榴辉岩相条件下熔融产生的。矿物(石榴子石、角闪石,单斜辉石和金红石)-熔体微量元素分配系数测定和部分熔融模拟结果进一步限定俯冲洋壳和下地壳起源的TTG/埃达克岩浆由含金红石角闪榴辉岩熔融产生,而拆沉下地壳起源的埃达克岩浆的产生要求软流圈地幔高温,由无水或含有少量含水矿物的榴辉岩熔融产生。     

盐类对甲烷水合物稳定性影响研究进展

甲烷水合物稳定性主要控制着甲烷水合物稳定带的厚度,温度、压力、孔隙水盐度和气体组分等因素影响着水合物稳定带的厚度。甲烷水合物的形成与地层水关系密切,而地层水中的各种盐离子(Cl~-、Na~+、Mg~(2+)、SO_4(~2-)、Ca~(2+))以及过渡金属(Fe、Mn、Cu、Co、Ni等)会影响天然气水合物的形成和分解条件。因此,研究盐类对甲烷水合物的稳定性认识有助于更加深入了解天然气水合物的成藏条件。本文分析了氯化物、硫酸盐、碳酸盐三大盐类对甲烷水合物稳定性的影响:同一盐类不同盐度条件下,随着盐度的增加,甲烷水合物相平衡曲线向低温高压偏移。总结了不同盐类和阴阳离子对甲烷水合物的抑制作用大小:在相同浓度、不同盐类条件下,盐类浓度在1.0~1.5 mol/L时盐类对甲烷水合物的抑制作用大小为MgCl_2CaCl_2Na ClKCl,盐类浓度大于1.5 mol/L时CaCl_2的抑制作用较强;阴离子对甲烷水合物的抑制作用大小争议较大,阳离子中Mg~(2+)对甲烷水合物的抑制作用最强。从目前的研究成果来看,已有数据与实际地质条件还存在一定差距,需要在真实实验条件下加强氯化物-硫酸盐-碳酸盐-甲烷-水体系的详细研究。本文提出,将高压可视反应腔与显微激光拉曼技术相结合,有望准确获取天然气水合物稳定形成时的温压条件,明确盐类和阴阳离子的抑制作用大小,以及盐类和离子特性如何影响水合物的形成和稳定,以便为未来的水合物勘探开发提供参考。     

Ag_2S-Cu_2S-PbS和Ag_2S-Cu_2S-Bi_2S_3体系相关系及相关矿物共生组合研究

本文用抽空石英管法对三元硫化物体系Ag_2S-Cu_2S-PbS和Ag_2S-Cu_2S-Bi_2S_3在500℃的相图进行了研究。 Ag_2S-Cu_2S-PbS体系500℃相关系,受方铅矿和固溶体f.c.c.(Ag_xCu_(2-x)S)、b.c.c.(Cu_xAg_(2-x)S)所控制。在接近PbS-Cu_2S连线处有一液相区。随温度下降,方铅矿可与Cu_2-Ag_2S二元系上所有各相平衡共存。 Ag_2S-Cu_2S-Bi_2S_3体系在500℃时则包含六个固溶体,即块硫铋银矿、铜银铅铋矿、杂硫铋银矿、硫铋铜矿、CuBi_3S_5、Cu_3Bi_5S_9和新合成“C”(Ag_(1.1)Cu_(4.8)Bi_(5.8)S_(12))。最令人感兴趣的是无铜、无铅的铜银铅铋矿(Ag_2Bi_4S_7)合成成功。 以上二个三元系中矿物稳定性及共生关系也根据相图研究结果进行了讨论。     

Cu-Mo-Sn-S四元系相关系

对Cu-Mo-Sn-S四元系500-640℃的相关系进行研究,并对相关的Cu-Sn-S三元系做了进一步研究与测定。实验表明,500℃时Cu-Sn-S系的稳定的三元化合物有Cu_4SnS_4、Cu_4SnS_6(或Cu_(9.75)Sn_(2.17)S_(13))、Cu_5Sn_2S_7(或Cu_(4.90)Sn_2S_(7.01))、Cu_2SnS_3和Cu_2Sn_3S_7(或Cu_2Sn_(3.26)S_(7.51))。这些三元化合物,除Cu_4SnS_4外,都与硫形成双变关系。 Cu-Mo-Sn-S四元系在500℃时相关系主要表现为MoS_2与Cu_4SnS_6、Cu_5Sn_2S_7、Cu_2SnS_3和Cu_2Sn_3S_7等各相的双变关系,以及金属与Cu_4SnS_4、Cu_5Sn_2S_7、Cu_2SnS_3和Cu_2Sn_3S_7的双变关系。 以不同起始原料,不同温度和方法合成Cu-Mo-Sn-S四元系中唯一的四元化合物——硫钼锡铜矿未获得成功。