流体包裹体及石英LA-ICP-MS分析方法的建立及其在矿床学中的应用

流体包裹体LA-ICP-MS(激光剥蚀-电感耦合等离子体质谱仪)分析具有高精度、低检测限、多元素同时微区原位检测的特点,因此在精细刻画成矿过程、深入揭示成矿机理方面具有传统方法无可比拟的优势。通过人工合成石英Na Cl-H2O-Rb-Cs和Na Cl-KCl-Ca Cl2-H2O-Rb-Cs流体包裹体,使用NIST610为外标、显微测温Na Cl等效盐度(电价平衡方法)为内标,建立了流体包裹体L A-ICP-MS分析方法。分析结果的相对误差在±16%以内,绝大部分在±10%以内,相对标准偏差(RSD)小于7%。同时结合国际上推荐的石英标样,使用NIST610为外标、无内标法,建立了石英微量元素LA-ICP-MS分析方法。分析结果表明,石英中主要元素Li、Al和Ti的相对误差在±10%以内,相对标准偏差小于5%。利用建立的方法对鲁西早白垩世王家庄Cu-Mo矿开展了应用研究,结果显示该矿富气相包裹体更富Cu,而含子矿物包裹体富Mo,暗示Cu和Mo可能具有不同的搬运机制,Cu更倾向于气相,Mo则倾向于进入液相,结合流体沸腾现象的存在,这可能是导致该矿上铜下钼分带沉淀的重要因素。此外,从早期岩浆成因石英到成矿期热液石英以及成矿期后石英,微量元素具有明显的Ti降低而Al升高的趋势,暗示成矿元素Cu、Mo的沉淀可能同时还受到温度和流体酸碱度变化的控制。     

Hydrogeophysical modelling of Hisarcik (Kütahya) geothermal field,western Turkey

Western Anatolia hosts many low-to-moderate and high-temperature geothermal sources in which active faults play a dominant role to control the recharge and the discharge of geothermal fluid. In this study, we used the two-dimensional geoelectric structure of Kütahya Hisarcık geothermal field, and created a conceptual hydrogeophysical model that includes faults, real topographical variations and geological units. The temperature distribution and fluid flow pattern are also investigated. The depth extension of Hisarcık Fault, electrical basement and low resistivity anomalies related to the presence of geothermal fluid are determined by using resistivity studies in the area. Numerical simulations suggest that Hisarcık fault functioning as a fluid conduit primarily enables hot fluid to be transported from depth to the surface. It is shown that the locations of predicted outflow vents coincide with those of hot springs in the area.     

利用体波层析成像技术研究欧亚及邻区地幔三维速度结构

根据体波层析成像技术,利用大量走时数据,做出0°~180°E,30°S~90°S范围内0~2889km深的三维速度分布图像,得到欧亚地区局部区域岩石圈及地幔的高分辨率速度结构,并从地球动力学角度出发对这些成像结果做进一步解释。     

鄂尔多斯盆地陕北斜坡延长区块储层流体识别

延长油田区块位于鄂尔多斯盆地陕北斜坡东部延安单斜的中间部位,为研究天然气储层及储层中高含气分布区,2008年在延长油田区块内完成三维地震勘探344km2。本文对三维地震资料应用吸收系数、频谱分解、振幅衰减等地震属性进行流体识别试验。试验结果表明振幅衰减对含气层段异常响应相对敏感,吸收系数对高含气层段有一定反映。利用天然气储层各层段振幅衰减极大值,参考吸收系数剖面的高值层段,分析预测了三维区块含气概率高的平面分布区,2009年在预测的含气概率高分布区进行了探井验证,取得了比较理想的效果。     

羊石坑汞矿床包裹体地球化学特征研究

羊石坑汞矿是80年代后期勘探的大型汞矿床,矿床位于川黔汞矿带北部,矿体以细脉、网脉浸染状为主。包裹体地球化学研究表明,成矿温度120～250℃,成矿流体盐度为10.6％(NaCl),流体沸腾发生在250℃左右,包裹体圈闭的最小压力为40×10~5Pa,成矿深度约为400m。结合成矿构造环境、构造演化、探讨了构造改造成矿机制和规律。     

Logs Fluid Typing Methods and Adaptive Analysis of Tight Sandstone Reservoir of Yingcheng Formation in Lishu Fault

Tight clastic reservoirs are characterized with low porosity and low permeability, which reduce contributions of reservoir fluids to geophysical logging responses, and it is more difficult to identify fluids of the reservoir. Therefore, it is necessary to study log interpretation and comprehensive evaluation methods for such clastic reservoirs. This study focused on geological characteristics of tight clastic reservoir of Yingcheng formation in Lishu Fault. Based on logs sensitivity to fluids, some fluid typing methods were discussed in detail, which included log curve overlap method, acoustic time overlapping method from density and neutron logs, porosity difference and ratio method, porosity-resistivity crossplot, normal distribution method, and other methods, and some effective fluid evaluation method were established and optimized. These above-mentioned methods were verified, which could achieve layer qualitative identification of tight sandstone in the study area. By contrast, two logs overlapping methods, porosity difference and ratio method, resistivity-porosity crossplot are more suitable for natural gas reservoirs, while porosity difference and ratio method, porosity-resistivity chart, normal distribution method are more suitable for oil and water reservoirs. The case study suggests that these methods be combined to archive more correct log interpretation in the study area, which provides important decision-making reference for oilfield exploration and development.     

地球排气作用——建立整体地球科学的一条统纲

通过研究发现 ,现在可以用地球排气作用作为一条统纲 ,把原来分散的地球科学各个分支学科和谐地串联成为一个整体地球科学巨系统。地球排气的实质是幔汁 (HACONS超临界态流体 )从深部自发向上、向外的辐射排放 ,结果形成了地球内外的 5个气圈和气体地球动力学 ,幔汁上涌后通过碱交代作用产生蚀变和岩浆并促使原来为固体的上地幔、地壳发生溃变 ,在地球的 3个基本动力 ,即重力、地球自转变速、圈层旋转差速和天体 (主要是月球 )潮汐力联合作用的大前提下诱发出大地构造运动、地球演化和自然灾害。没有幔汁活动就没有壳幔运动。笔者初步认为 ,对现有流行的众多理论和结论都需要重新加以怀疑和再审鉴。否则 ,地球科学难以向前发展。我们今后不仅需要单科的或局域的岩石学家、地球化学家、大地构造学家、气象学家、海洋学家等 ,另外还需要有一大批整体地球科学家。     

The Gravity Field of the Vogtland and NW Bohemia: Presentation of a Project

The Vogtland and NW Bohemia are characterized geoscientifically by periodically occurrence of swarm earthquakes. The basic geophysical mechanism is not yet sufficiently clarified, just like detail questions to geology in especially the deeper underground. Complex geophysical investigations in the seismoactive region indicate geodynamic phenomena like mass redistribution or stress accumulation and release (Spiák et al., 1998). According to Grünthal (1989) a weakness zone is suggested in the region of the swarm earthquakes. This zone can be caused by fluid-tectonics (Kämpf et al., 1992), a mantle plume (pers. com. J. Svancara, 1999) and/or by the geometry of the geological structures (Neunhöfer & Güth, 1988). A three-dimensional gravimetric model can clear up the underground situation. By means of high-resolution gravimetry a three-dimensional model will be developped for the Vogtland and NW Bohemia region. In the first step a homogeneous Bouguer map of the Vogtland and NW Bohemia was created (fig. 1) containing gravity structures analysed by Ibrmajer & Suk (1989) and Blízkovsky et al. (1985). The used gravimetric data were made available by the Saxonian National Office for Environment and Geology, by the Czech Geological Survey, Prague and by the GGA Hannover. In the context with the interpretation of the deep-seismic profile MVE 90 a two-dimensional gravimetric modeling was carried out (Behr et al., 1994), too. Anomaly-producing source bodies apparently do not offer themselves in a two-dimensional model, because after Jung (1961) the length of a gravimetric source structure must be about four times larger than it's width. The technique of the three-dimensional gravimetric modeling by means of any polyhedrons was developed by Götze (1976, 1984). Gravimetry is a potential method and supplies an infinite number of solutions, so the model has to be developed close to other geoscientific results. The aim is to construct a high-resolution three-dimensional underground model, which includes the upper earth's crust and the deep-seated structures of the middle and lower crust, too. The determination of the mass distribution in the underground supplies contradicting or supporting facts for geodynamic views in the Vogtland and NW Bohemia for example of Bankwitz et al. (1993). The interpretation of the Bouguer map of the Vogtland and a three-dimensional gravimetric model ought to contribute a substantial, also geodynamic part to understand the origin and the emergence of the swarm earthquakes in this region.     

内蒙古中部二叠纪碱性花岗岩及其地球动力学意义

西伯利亚板块南缘白音乌拉－东乌珠穆沁旗带的碱性花岗岩（Ｒｂ－Ｓｒ年龄２７６－２８６Ｍａ）生成于张性的构造环境，较西伯亚板块同中朝板块之间晚泥盆世－早石炭世的碰撞事件晚约６０Ｍａ，属于造山后的Ａ型花岗岩，可作为造山作用结束的标志。但在中朝板块北缘晚石炭世－二叠纪只发育钙碱性的晚造山花岗岩，直到三叠纪才出现碱性正长岩。相邻两大板块边缘之间岩浆活动的非对称性可能是受板块间面积和质量差别的制约。     

河南土门萤石脉型钼矿床流体包裹体研究及成因探讨

河南方城土门萤石脉型钼矿床位于栾川断裂北侧的华熊地块东南部.矿体呈断续的脉状、似层状、透镜状产于花岗斑岩外接触带,赋矿构造为大理岩与片岩之间的层间断层.矿石主要由萤石、硫化物和碳酸盐等矿物组成.矿脉穿插关系、矿石组构和矿物组合显示了4阶段矿化:分别以白色萤石(Ⅰ阶段)、紫色萤石-辉钼矿(Ⅱ阶段)、辉钼矿多金属硫化物(Ⅲ阶段)以及碳酸盐(Ⅳ阶段)为标志.各阶段萤石中流体包裹体可分为4类:NaCl-H_2O型(W类)、CO_2-H_2O-NaCl型(C类)、纯CO_2型(PC类)及含子晶包裹体(S类).冷热台测试显示,Ⅰ阶段均一温度为300～420℃,峰值为360～410℃,Ⅱ阶段均一温度180～380℃,峰值为220～300℃;Ⅰ阶段流体盐度高达49.68 wt% NaCl eqv.,Ⅱ阶段则不高于13.07 wt%NaCl eqv..从早到晚,W类包裹体平均密度由0.88g/cm~3减小到0.84g/cm~3,C类包裹体CO_2的平均密度由0.66g/cm~3增高到0.82g/cm~3.总体来说,土门萤石-钼矿床形成于中高温、高盐度、富CO_2和F的流体系统,成因上归属于大陆背景的浆控脉状热液成矿系统.