激光共聚焦扫描显微镜测定烃类包裹体气液比的误差校正研究

通过烃类包裹体PVT模拟可以重建捕获温度和捕获压力,气液比是影响PVT模拟结果的重要参数,然而由于缺少烃类包裹体标准样品,一直未能深入研究激光共聚焦显微镜气液比测定精度的问题。本文利用人工合成包裹体技术合成了一种用于校正激光共聚焦扫描显微镜(LSCM)测定气液比的烃类包裹体标准样品,根据已知的合成烃类包裹体的油气组成、捕获温度和捕获压力计算出烃类包裹体的理论气液比,并利用LSCM测定烃类包裹体的实际气液比,通过计算实际测试值与理论值的差值以分析实际测定气液比的误差,实现对激光共聚焦扫描显微镜的误差标定。实验结果证实,高分辨率的LSCM测定烃类包裹体气液比的绝对误差小于0.5%,可以为包裹体PVT模拟提供精确参数。本研究肯定了LSCM测定烃类包裹体气液比方法的准确性,进一步证实了烃类包裹体的PVT模拟结果可以为油气成藏研究提供可靠数据。     

利用高分辨率3D技术和荧光强度变化精确测量烃类包裹体体积的方法

烃类包裹体气液比的精度对PVT模拟结果可靠性有重要影响,而气液相边界的判断对气液比测定准确性至关重要。本文开发了一种精确测量烃类包裹体体积的方法,即利用高分辨率激光共聚焦显微扫描技术获取烃类包裹体3D图,在透射及荧光模式下用三维坐标标定液相的边界,利用3Dfor LSM软件计算烃类包裹体液相的体积;同时利用激光共聚焦显微荧光技术对横穿气液两相的直线进行线扫描,根据扫描线上荧光强度的突变判断气相边界,多次扫描求平均值作为气相直径。本方法避免了人为判断包裹体气相边界的不可靠性,对气液边界的确定精度可达0.02μm,提高了气液比测试精度,使得利用包裹体恢复古压力结果更加可靠。     

烃类包裹体理论气液比计算方法及其误差分析

<正>烃类包裹体作为流体包裹体家族中特殊的一类,是油气流体保留下来的原始样品,在油气运移和油气成藏研究中有着广泛的应用,通过对其分析可以获得有关地质过程的流体信息[1]。其中烃类包裹体的气液比是进行PVT模拟的重要参数,准确获取烃类包裹体的气液比十分重要[2]。在高温高压条件下,如果矿物在形成或生长时所捕获的流体为均匀的单一相,流体相可以充满整个包裹体空腔。但是随着温度、压力的下降,流体相会发生相分离,因包裹体中不同流体的收缩系数不同,就     

气泡突变法判断气液包裹体的冰点

本文在观察冻结的气液包裹体温度回升时气泡变化的基础上,分别用气泡突变和冰晶消失两种判断方法测定同一包裹体冰点。经比较,说明两种判断结果是一致的。结果表明:对冷冻时无法观察到冰晶的较小包裹体的冰点,用气泡突变法可以判断,其结果清楚、准确。可见该方法在包裹体的点测定中具有重要的实际意义。     

利用天然气包裹体方法划分天然气成藏期次--以鄂尔多斯盆地东南部上古生界储层为例

鄂尔多斯盆地东南部上古生界天然气储层主要为太原组、山西组、下石盒子组和上石盒子组,岩性以石英砂岩为主。储层的主要成岩作用有压实和压溶作用、胶结和交代作用、裂隙和溶蚀作用等,依据显微镜下岩相学研究,在研究区可以识别出四个大的成岩阶段,分别对应早成岩阶段的早期和晚期、晚成岩阶段的早期和晚期。识别出两期天然气包裹体,第一期天然气包裹体形成于早成岩阶段的晚期,分布在早期裂隙及与其相关的溶蚀孔隙中,形态不规则,气/液比较高,偶尔可见包裹体发荧光。第二期天然气包裹体形成于晚成岩阶段晚期,分布在晚期裂隙中和晚期亮晶方解石和石英胶结物中,包裹体气/液比小,大部分为有机气态和盐水组成的气液两相有机包裹体,包裹体壁薄色浅。研究认为第一期代表了早期天然气初次运移和注入储层事件,而第二期代表了天然气大规模二次运移聚集成藏事件。     

共生黑钨矿与石英等多种矿物中流体包裹体的红外显微测温对比研究——以江西西华山石英脉钨矿床为例

西华山钨矿床是一个产于燕山期花岗岩中的大脉型钨矿床。已有百余年的开采史。但在矿床成矿条件和成矿流体性质等方面一直存在不同认识。作者利用红外显微镜及其它相关设备,对西华山矿床不同中段样品中的黑钨矿、锡石、绿柱石、黄铁矿、闪锌矿、石英和萤石中的流体包裹体进行了详细对比研究。结果显示,蚀变花岗岩中造岩石英只见次生气液包裹体,晶洞水晶中只有原生包裹体,而云英岩石英中原生、次生包裹体均较发育。黑钨矿中以原生气液包裹体为主,在早期结晶的黑钨矿中还有较多的硅酸盐熔融包裹体,而晶洞中的黑钨矿和水晶一样——只有原生气液包裹体。绿柱石中除了硅酸盐包裹体外,主要是气液包裹体(多为次生)。其它锡石、黄铁矿、闪锌矿和萤石等都只有气液包裹体(原生或次生)。研究结果表明,西华山钨矿床的初始成矿流体是一种岩浆——热液过渡性流体,尔后才演变成单一的热水溶液,在这一过程中黑钨矿、黄铁矿、闪锌矿、萤石和石英等矿物不断晶出。矿床总的成矿温度大致为700~200℃,压力约为160~200MPa。各种气液包裹体的盐度主要为5.0%~10%Na Cleqv。文中还对这些数据的地质意义以及对脉钨矿床流体包裹体研究和数据解释中的某些问题进行了较深入的讨论。     

滇黔交界地区玄武岩铜矿流体包裹体地球化学特征

为了探讨玄武岩铜矿成矿流体的特征,对滇黔交界地区峨眉山玄武岩铜矿3个成矿期次铜矿石中石英和方解石的气液包裹体进行了激光拉曼成分研究和均一温度、盐度测定,对古石油包裹体通过荧光显微镜进行了成分鉴定。结果表明：第1、2期次成矿流体主要为盆地卤水,其气液包裹体气液比小（一般5%～10%）,w（NaCl）为8%～22%,气相为甲烷,液相为水,无子晶及液相CO2,均一温度为80℃～260℃;第2期次成矿流体除盆地卤水外,还有以古石油为代表的有机流体,古石油包裹体由液态烃、固体沥青和气相组成,均一温度变化大（30℃～290℃）,液态烃以荧光性强的芳烃为主;第3期次成矿流体具有大气降水成因,其气液包裹体气液比一般为5%～10%,w（NaCl）〈4%,无子晶及液相CO2,均一温度140℃～270℃,但以小于200℃为主。从第1期次到第3期次,成矿流体盐度逐渐降低,特别是第3期次的盐度非常低,但温度变化不明显。本区最重要的自然铜沉淀富集成矿是第2期次不同性质成矿流体混合或成矿流体与有机流体混合、有机质的还原的结果。     

贵州晴隆大厂锑矿床辉锑矿中流体包裹体的红外显微测温学研究

应用红外显微镜和流体包裹体显微测温分析技术,对晴隆大厂锑矿床辉锑矿和萤石中的流体包裹体进行了对比研究。研究表明,该矿床辉锑矿与萤石中的流体包裹体类型、均一温度和盐度存在明显差异。辉锑矿中的流体包裹体以含子晶-气-液三相包裹体和气-液两相包裹体为主,具有较高的盐度(0.18%~19.45%Na Cleqv)和均一温度(153~285℃),并具有明显的正相关关系,而萤石则主要发育气-液两相流体包裹体,具有较低的盐度(0.18%~1.91%Na Cleqv)和均一温度(144~176℃),认为形成辉锑矿和萤石的成矿流体来自不同的源区,流体混合导致的温度和盐度降低可能是锑成矿的重要控制因素之一。辉锑矿硫同位素研究进一步揭示其成矿物质主要来自地幔,可能与晴隆地区及其外围的基性-超基性岩浆活动的地质背景有一定的成因联系。     

新疆西准噶尔宏远钼矿床和吐克吐克钼铜矿床流体包裹体特征及成矿时代

宏远（铜）钼矿和吐克吐克钼铜矿为新疆西准噶尔地区新发现的斑岩型矿床。流体包裹体测温和激光拉曼探针分析研究表明,宏远（铜）钼矿发育气液、气体和含子矿物包裹体等3类包裹体,气液比变化大,均一温度集中在140 ℃～200 ℃和260 ℃～340 ℃两个区间,吐克吐克钼铜矿只含有气液和含子矿物两类包裹体,气液比变化小,均一温度集中在180 ℃～220 ℃。两个矿区均发育高盐度和低盐度的NaCl-H₂O-CH₄-CO₂流体,显示含甲烷还原性流体的性质。宏远（铜）钼矿辉钼矿Re-Os同位素分析表明其成矿年龄为314.3±1.9 Ma,与西准噶尔包古图斑岩铜矿成矿时代一致。     

山东沂南金铜铁矿床中的液态不混溶作用与成矿：流体包裹体和氢氧同位素 证据

沂南矽卡岩型金铜铁矿床产于燕山期中酸性侵入岩与新太古界—寒武系地层接触带附近。氢、氧同位素研究表明,早期干矽卡岩阶段(Ⅰ)和湿矽卡岩-磁铁矿阶段(Ⅱ)的成矿流体主要为岩浆水,晚期石英-硫化物阶段(Ⅲ)和碳酸盐阶段(Ⅳ)的成矿流体则显示有大气降水混入的岩浆水特点。流体包裹体研究表明,成矿各阶段热液矿物中的包裹体类型丰富,以气液两相盐水包裹体、含子晶多相包裹体和CO2-H2O包裹体为主,次为纯液相水包裹体和纯气相水包裹体,偶见晶质熔融包裹体。由Ⅰ→Ⅱ→Ⅲ→Ⅳ阶段,气液水包裹体均一温度(520～430℃→430～340℃→250～190℃→190～130℃)呈现逐渐降低的趋势。在Ⅰ、Ⅱ阶段的石榴子石和绿帘石中,晶质熔融包裹体与同期次捕获的具不同气相分数的气液水包裹体及含子晶的多相包裹体共生,表明它们被捕获时是一种熔体与流体共存的不混溶状态。在Ⅲ阶段的石英(少量Ⅱ阶段的绿帘石)中,常见气相充填度变化很大的气液水包裹体与同期次捕获的纯液相水包裹体、纯气相水包裹体、含子晶的多相包裹体以及CO2-H2O包裹体共生,且共生的不同类型包裹体均一温度相近,表明此阶段成矿流体曾发生过广泛的沸腾(不混溶)。因而认为,在沂南矿床由岩浆...     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)