CCSD HP-UHP变质岩石英脉和东海水晶中有机包裹体的发现及其意义   总被引：2，自引：0，他引：2       下载免费PDF全文

徐莉 孙晓明翟伟  梁业恒汤倩 梁金龙 《地质学报》2007,81(5):654-658,I0002

荧光显微镜下观察、激光拉曼和显微红外测试,首次在CCSDHP-UHP变质岩石英脉和东海水晶中发现了含有沥青和烃类的有机包裹体,进一步证实大别-苏鲁超高压变质带曾经历了快速的俯冲与折返过程,俯冲板块沉积物中的有机质未能充分地演化和成熟。俯冲板块在进变质过程中强烈脱水,释放出含烃流体,并被在板块抬升及其伴随的减压重结晶和退变质过程中形成的石英脉和水晶体所俘获。  相似文献   

Cryptic crustal contamination of MORB primitive melts recorded in olivine-hosted glass and mineral inclusions     

Vadim S. Kamenetsky  Andrey A. Gurenko 《Contributions to Mineralogy and Petrology》2007,153(4):465-481

The origin of compositional heterogeneities among the magmas parental to mid-ocean ridge basalts (MORB) was investigated using a single rock piece of the olivine-phyric basalt from 43°N, Mid-Atlantic Ridge (AII D11-177). The exceptional feature of this sample is presence of very primitive olivine crystals (90–91 mol% Fo) that are significantly variable in terms of CaO (0.15–0.35 wt%). A population of low-Ca olivine (0.15–0.25 wt% CaO) is also notably distinct from high-Ca olivine population in AII D11-177, and primitive MORB olivine in general, in having unusual assemblage of trapped mineral and glass inclusions. Mineral inclusions are represented by high-magnesian (Mg# 90.7–91.1 mol%) orthopyroxene and Cr-spinel, distinctly enriched in TiO₂ (up to 5 wt%, c.f. <1 wt% in common MORB spinel). Glass inclusions associated with orthopyroxene and high-Ti Cr-spinel have andesitic compositions (53–58 wt% SiO₂). Compared to the pillow-rim glass and “normal” MORB inclusions, the Si-rich glass inclusions in low-Ca olivine have strongly reduced Ca and elevated concentrations of Ti, Na, K, P, Cl, and highly incompatible trace elements. Strong variability is recorded among glass inclusions within a single olivine phenocrysts. We argue that the observed compositional anomalies are mineralogically controlled, and thus may arise from the interaction between hot MORB magmas and crystal cumulates in the oceanic crust or magma chamber.  相似文献   

内蒙古兴和地区太古宙孔兹岩系变质峰期流体特征     

董永胜  周喜文 《吉林大学学报(地球科学版)》2001,31(2):122-125

为了查明麻粒岩相变质高峰期的流体特征 ,对研究区太古宙孔兹岩系变质峰期特征矿物夕线石中具负晶形的碳质液相包裹体进行了冷热台显微测温和激光拉曼光谱成分测定。研究表明 ,该类包裹体xH2 O很低 (0mol%～ 17mol% ) ,碳质成分很高 (xCO2 +CH4=70mol %～ 90mol% ) ,密度为0 .94～ 1.0g/cm3 ,相应压力约为 0 .7GPa。流体氧逸度的lg fO2 在 - 14～ - 16之间。研究结果表明 ,丰富的碳质组分不是深部来源的 ,而可能是由孔兹岩系原岩中有机质氧化作用产生。  相似文献   

Radiogenic isotopes in fluid inclusions   总被引：7，自引：0，他引：7  

Igor M. Villa   《Lithos》2001,55(1-4):115-124

Radiogenic isotopes studied in fluid inclusions are still a limited field, with great potential for expansion as analytical techniques improve. The main limitation for Sr, Ar and He isotope work is the very small number of radiogenic atoms produced in a typical fluid inclusion. The requirements to analysts are correspondingly high. Examples show that isotopic tracing on fluid inclusion fluids can be a decisive tool in solving geological problems.  相似文献   

Petroleum inclusions in sedimentary basins: systematics, analytical methods and applications   总被引：21，自引：0，他引：21  

Ingrid Anne Munz   《Lithos》2001,55(1-4):195-212

Fluid dynamics in sedimentary basins is of tremendous interest, both from a scientific and an economic point of view. Integration between fluid inclusion and present-day fluid data provides the time aspect necessary for reconstruction of fluid flow paths, and can be used for mapping fluid dynamics both on a regional basin scale or on the more local scale of petroleum reservoirs. This paper presents a review of analytical and modelling methods for petroleum in fluid inclusions. Essentially, four types of data for petroleum inclusions can be established through analysis and modelling: (1) textures (which give indirect information of the time aspect), (2) fluid composition, (3) fluid properties and (4) pressure–temperature of trapping. During the last decade, development of analytical methods for determination of inclusion fluid compositions has taken place. Traditional correlation studies for characterisation of maturity and source facies may now therefore include fluid inclusion data. The development has also been directed towards an improved understanding of the physical properties of petroleum inclusions. Although these methods are in their early stages concerning precision and accuracy, data necessary for fluid flow modelling, such as fluid densities, viscosities, pressure and temperature, can be estimated.  相似文献   

人造气液包裹体方法及其在研究热液性质中的应用   总被引：3，自引：0，他引：3       下载免费PDF全文

张毅刚 《地质科学》1992,(2):141-148

人造气液包裹体方法在研究热液的物理化学性质方面较传统方法简便、易行。它可用于研究热液的等容线、不混溶性质及矿物在热液中的溶解度。本文解释了人造气液包裹体的合成方法和人造气液包裹体方法的原理,分述了应用此方法研究热液所取得的最新成果。此法不仅能用于研究热液的性质,也能用于其它方面的研究,具有广阔的前景。  相似文献   

上地幔流体的性质和作用——从女山幔源二辉橄榄岩捕虏体获得的证据   总被引：2，自引：0，他引：2  

夏林圻  夏祖春  张诚 《西北地质科学》1992,(2)

玄武岩浆从地幔深处挟带上来的超镁铁质捕虏体含有地幔流体的直接证据,它们对于阐明地幔深部地质作用(部分熔融作用、地幔交代作用)的机制十分重要。女山幔源二辉橄榄岩的研究结果表明,初始的地幔流体除富含CO_2外,尚含有H_2O和少量CO、CH_4、SO_2、C1、F。地幔中的初始流体(挥发组分)在源部是溶解于地幔橄揽岩的高压固体矿物相中,它们在地幔上隆减压时出溶,形成细小的最早期流体包裹体。这些自由流体相在一定部应聚集,使得地幔固相线(和液相线)下降,引起上地幔发生减压部分熔融。初始的部分熔融主要发生于矿物边界,以单斜辉石最易遭受,形成矿物边缘的海绵状部分熔融带。当地幔剪切流动时,初始的部分熔融体珠滴联合成大的珠滴,并开始渗透,在变形橄榄岩中相连成脉状网络,晚期含C0_2岩浆包裹体及填隙玻璃即为其代表。由于剪裂作用,熔体(和流体)压裂开上覆橄榄岩,产生岩墙状通道,并在上地幔的某些低压区聚集成岩浆库。流体和熔体均为地幔交代作用的介质。在流体参与下,上地幔低度部分熔融产生的熔体将高度富集不相容元素。这些熔体和流体与亏损地幔间的相互作用,可以带来不相容元素重大的局部富集。当流体(和熔体)中H_2O浓度低时,仅发生隐交代作用;当H_2O浓度较高时,部分熔融程度也较高,相应有含水相(如角闪石等)成核,出现矿物交代作用。  相似文献   

山东沂水麻粒岩杂岩中的变质流体及地质意义   总被引：2，自引：0，他引：2  

徐惠芬  沈其韩 《华北地质矿产杂志》1995,10(2):154-166

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。  相似文献   

Experimental diffusion of hydrogen into synthetic fluid inclusions in quartz   总被引：2，自引：0，他引：2  

D. L. HALL  S. M. STERNER 《Journal of Metamorphic Geology》1995,13(3):345-355

Abstract Quartz-hosted, synthetic CO₂-H₂O fluid inclusions behave as open systems with respect to diffusional transfer of hydrogen during laboratory-simulated metamorphic re-equilibration at 650, 750 and 825°C and 1.5 kbar total pressure with f_O2 defined by the C-CH₄ buffer. Microthermometry and Raman spectroscopy show that the initial CO₂-H₂O inclusions become CO₂-CH₄-H₂-H_2O
inclusions after diffusive influx of hydrogen from the reducing confining medium. Measurable changes are observed in inclusion compositions after only 15 days of re-equilibration, implying significant hydrogen mobility at still lower temperatures over geological time spans. Results of synthetic inclusion re-equilibrium experiments have profound implications for the interpretation of natural fluid-inclusion data; failure to account for potential hydrogen migration in inclusions from high-temperature geological environments may lead to erroneous estimates of P-T, and/or the compositions of metamorphic fluids.  相似文献   

不同晶形石盐沉积生长特征及对包裹体温度的影响     

冯阵东  吴伟  周永  刘惟庆  魏国营  贾天让 《地质学报》2022,96(4):1469-1477

石盐晶体生长过程中捕获流体包裹体，利用冷冻测温法得到的均一温度信息与古水温存在良好的相关性。在部分地区，利用包裹体最大均一温度评价古气候时，温度数据与孢粉学反映的气候特征存在冲突，不同晶形的石盐沉积特征，及其晶体条纹内包裹体温度代表的地质含义需进一步探讨。笔者在分析经典测温数据的基础上，观察常温蒸发实验中漏斗晶和人字晶的形成及生长过程，分析了不同温度段均一温度与气温、水温之间的关系。结合现代气象记录数据，分析了最大均一温度评价气候时存在的局限性。研究认为：漏斗晶晶核形成与卤水表面，包裹体温度受温度和气压共同影响，漏斗晶在卤水底部绕核生长，漏斗晶外围包裹体温度对应水底温度，沉入水下后漏斗晶生长缓慢，包裹体最大温度可能代表年度最高温度，以此为指标评价气候得出的结论过于炎热；人字晶是多个漏斗晶之间的桥接部分，大部分形成于卤水蒸发将近结束之时，人字形条纹内包裹体温度受气温和地表温度共同影响，地表温度远大于气温是造成包裹体最高温度过高的主要原因。  相似文献