山东沂水麻粒岩杂岩中的变质流体及地质意义

山东沂水麻粒岩杂岩中含有大量高密度富ＣＯ＿２流体包裹体，伴随有ＣＯ＿２－Ｈ２Ｏ，ＣＯ＿２±Ｎ＿２±ｃＨ＿４的包裹体。对这些包裹体的产状、分布和组成等特征进行了详细的岩相学研究，并选择有代表性样品进行了显微测温和激光拉曼探针分析。结合本区地质和岩石学研究成果确定沂水麻粒岩杂岩峰期变质温度为８００℃，压力为０．７５ＧＰａ。对变质流体组成、演化及其成岩意义也进行了讨论。     

对矿物包裹体溶液性质的新认识——兼论含矿溶液是酸性溶液的地质证据

对金属矿床成矿溶液的性质 ,特别是 pH值 (酸碱度 )的确定 ,是认识含矿溶液的成因、成矿条件和成矿机理的关键。目前对成矿溶液性质的研究主要局限在对围岩蚀变矿物包裹体的测定方面 ,并得出近中性热卤水成矿的结论。作者认为 ,多数围岩蚀变矿物的包裹体溶液不能代表原成矿溶液的性质 ,“近中性的热卤水成矿”的认识有误 ,应是酸性水形成的含矿溶液成矿 ,并从矿物包裹体溶液的特征、Roedder的高金属含量的矿物包裹体溶液的发现、氢氧同位素资料、矿物包裹体中高卤水溶液的起源以及成矿溶液的演化机理等方面论述了酸性金属含矿溶液的成因及成矿演化过程。     

相山铀矿田邹家山矿床成矿流体特征

通过流体包裹体的岩相学研究、显微测温和激光拉曼探针测试,探讨了邹家山铀矿床成矿流体特征、演化及矿质沉淀方式。研究结果表明,该矿床的成矿流体为中低温热液,碳氢化合物对铀的富集具有不可忽视的作用,流体持续的沸腾作用是矿质沉淀的主要因素。     

FTIR Spectrum of Phenocryst Olivine as an Indicator of Silica Saturation in Magmas

Fourier Transform infrared (FTIR) absorption spectra of hydroxylwere measured on olivine phenocrysts from hydrous basaltic meltsthat originated in island-arc tectonic settings. The basalticmelts encompass a wide range of silica activities from orthopyroxene-saturatedhypersthene-normative to nepheline-normative compositions. Theintensities and wavenumber placement of hydroxyl absorptionbands correlate with the degree of silica saturation of theparent melt from which the olivine crystallized. Olivines fromsilica-undersaturated nepheline-normative melts absorb IR radiationin the wavenumber range 3430–3590 cm^–1 (Group 1).In contrast, olivines from orthopyroxene-saturated boniniticmelts exhibit hydroxyl absorption bands in the wavenumber range3285–3380 cm^–1 (Group 2). Olivines crystallizedat intermediate silica activities exhibit a combination of thetwo groups of hydroxyl IR bands, where the proportion of Group2 bands increases with increasing silica saturation of the parentmelt. The positions of hydroxyl absorption peaks observed herefor natural samples are consistent with previous measurementson experimentally annealed olivines. Thus protonation experimentscan be employed to make spectroscopically dry olivine structuresvisible by IR, yielding information on the silica saturationof the parental magmas. Hydroxyl concentrations in the studiedolivines were estimated to be 1–2 ppm, corresponding toan olivine–melt partition coefficient of (1·0 ±0·3) x 10^–4. KEY WORDS: nominally anhydrous minerals; olivine; water; mantle; silica activity; melt inclusions     

P–T–fluid evolution in the Mahalapye Complex, Limpopo high-grade terrane, eastern Botswana

Metapelites, migmatites and granites from the c. 2 Ga Mahalapye Complex have been studied for determining the P–T–fluid influence on mineral assemblages and local equilibrium compositions in the rocks from the extreme southwestern part of the Central Zone of the Limpopo high‐grade terrane in Botswana. It was found that fluid infiltration played a leading role in the formation of the rocks. This conclusion is based on both well‐developed textures inferred to record metasomatic reactions, such as Bt ? And + Qtz + (K₂O) and Bt ± Qtz ? Sil + Kfs + Ms ± Pl, and zonation of Ms | Bt + Qtz | And + Qtz and Grt | Crd | Pl | Kfs + Qtz reflecting a perfect mobility (Korzhinskii terminology) of some chemical components. The conclusion is also supported by the results of a fluid inclusion study. CO₂ and H₂O ( = 0.6) are the major components of the fluid. The fluid has been trapped synchronously along the retrograde P–T path. The P–T path was derived using mineral thermobarometry and a combination of mineral thermometry and fluid inclusion density data. The Mahalapye Complex experienced low‐pressure granulite facies metamorphism with a retrograde evolution from 770 °C and 5.5 kbar to 560 °C and 2 kbar, presumably at c. 2 Ga.     

基于模糊数学综合评判的库岸稳定性分段——以新疆某水电站近坝库岸为例

从影响库岸稳定性的诸因素中筛选出六个主要因素：坡度、坡体形态、坡体完整性程度、库水面宽度、主风向与库岸夹角及坡体结构,根据其影响程度确定了它们的权重,将库岸稳定性分为良好、较好、较差和差四级。按照各个影响因素对斜坡和各级稳定性的影响不同,对各单因素进行离散化处理,得到各影响因素的隶属度矩阵。通过对各单因素矩阵与影响因素权重运算,得到各个单元分区的稳定性评价结果。运用该方法对新疆某水电站近坝库岸段20km的稳定性进行了评价,认为稳定性较差库岸段总长约4.1km,占20.3%,主要为地质灾害分布处及工程地质条件较差的地段。该综合评判成果与现场勘察及遥感解译结果较为一致。     

油气和含油气包裹体及其在油气地质地球化学研究中的意义

本文在综合前人研究的基础上，结合笔者的工作经验，提出了一个实用的油气和含油气包裹体分类方案，详细论述了各类油气和含油气包裹体的相态、组成和均一温度特征。在同一油气藏，均一温度越高，油相包裹体中的气态烃和挥发份的含量也越高。依据油相包裹体的均一温度的变化及其与同生水溶液包裹体的均一温度的关系可以研究油气藏在充填过程中油气组成，特别是气态烃和挥发份含量的演变。进而可以研究油气藏的油源--生油岩的类型和热演化程度。本文评述了依据油相包裹体和同生水溶液包裹体ＰＶＴ相图推断其捕获温度和压力范围的有效性和局限性。最后讨论了各类油气和含油气包裹体的成因机制及其在油气地质和地球化学研究中的意义。     

资阳地区震旦系古岩溶储层特征及测井评价

位于四川盆地的资阳地区在震旦系灯影组中发现了继威远震旦系气藏之后的又一大型气藏。区内７口钻井揭露的地层显示本区灯影组主要由一套震层状白云岩民,基质岩块具低孔低渗特点,有效的储集空间是由受古岩溶作用产生的溶蚀孔洞和构造作用产徨的裂缝共同构成,溶洞具有数量多,大洞多,发育集中的特点,裂缝具有成因,多期次,多产状的特点,对这套以缝洞型为玉的储层,由常规测井资料计算单一的物性参数（如孔隙度等）的方法难以其     

显微荧光光谱技术在油气成藏研究中的应用——以塔里木盆地巴什托上古生界油气藏为例

根据原油在紫外光的激发下产生荧光的特点,通过显微荧光光谱方法,对有机包裹体的荧光光谱进行定量化分析,利用其主峰波长与荧光强度、主峰波长与红/绿商的相关性,对塔里木盆地巴什托上古生界油气藏的成藏特征进行了初步研究。在研究区所采集的32块岩石样品中共获得64个荧光光谱数据。分析结果表明,巴什托上古生界油气藏存在3个油源,其主峰波长主要集中在439~443nm、469~472 nm和498~503 nm三个值段上,且为不同演化阶段的混源充注。前两者来自于寒武—奥陶系烃源岩,由下至上充注成藏;后一油源来自于石炭系巴楚组,随演化程度的变化同时向上、下两个方向充注。综合同期捕获不同主峰波长的有机包裹体,推测研究区至少存在4期油充注、1期天然气充注。     

Magmatic evolution of Li–F, rare-metal granites: a case study of melt inclusions in the Khangilay complex, Eastern Transbaikalia (Russia)

We report compositions of homogenized quartz-hosted melt inclusions from a layered sequence of Li-, F-rich granites in the Khangilay complex that document the range of melt evolution from barren biotite granites to Ta-rich, lepidolite–amazonite–albite granites. The melt inclusions are crystalline at room temperature and were homogenized in a rapid-quench hydrothermal apparatus at 200 MPa before analysis. Homogenization runs determined solidus temperatures near 550 °C and full homogenization between 650 and 750 °C. The compositions of inclusions, determined by electron microprobe and Raman spectroscopy (for H₂O), show regular overall trends of increasing differentiation from the least-evolved Khangilay units to apical units in the Orlovka intrusion. Total volatile contents in the most-evolved melts reach over 11 wt.% (H₂O: 8.6 wt.%, F: 1.6 wt.%, B₂O₃: 1.5 wt.%). Concentrations of Rb range from about 1000 to 3600 ppm but other trace elements could not be measured reliably by electron microprobe. The resulting trends of melt evolution are similar to those described by the whole-rock samples, despite petrographic evidence for albite- and mica-rich segregations previously taken as evidence for post-magmatic metasomatism.

Melt variation trends in most samples are consistent with fractional crystallization as the main process of magma evolution and residual melt compositions plot at the granite minimum in the normative Qz–Ab–Or system. However, melts trapped in the highly evolved pegmatitic samples from Orlovka deviate from the minimum melt composition and show compositional variations in Al, Na and K that requires a different explanation. We suggest that unmixing of the late-stage residual melt into an aluminosilicate melt and a salt-rich dense aqueous fluid (hydrosaline melt) occurred. Experimental data show the effectiveness of this process to separate K (aluminosilicate melt) from Na (hydrosaline melt) and high mobility of the latter due to its low viscosity and relatively low density may explain local zones of albitization in the upper parts of the granite.