花岗岩风化土微观结构及其工程地质特性研究

Saprolite is the residual soil resulted from completely weathered or highly weathered granite and with corestones of parent rock. It is widely distributed in Hong Kong. Slope instability usually happens in this layer of residual soil and thus it is very important to study the engineering geological properties of Saprolite. Due to the relic granitic texture, the deformation and strength characteristics of Saprolite are very different from normal residual soils. In order to investigate the effects of the special microstructure on soil deformation and strength, a series of physical, chemical and mechanical tests were conducted on Saprolite at Kowloon, Hong Kong. The tests include chemical analysis, particle size analysis, mineral composition analysis, mercury injection, consolidation test, direct shear test, triaxial shear test, optical analysis, SEM & TEM analysis, and triaxial shear tests under real-time CT monitoring.Based on the testing results, intensity and degree of weathering were classified, factors affecting and controlling the deformation and strength of Saprolite were identified, and the interaction between those factors were analyzed.The major parameters describing soil microstructure were introduced mainly based on optical thin section analysis results. These parameters are of importance and physical meaning to describe particle shape, particle size distribution (PSD), and for numerical modeling of soil microstructure. A few parameters to depict particle geometry were proposed or improved. These parameters can be used to regenerate the particle shape and its distribution. Fractal dimension of particle shape was proposed to describe irregularity of particle shapes and capacity of space filling quantitatively. And the effect of fractal dimension of particle shape on soil strength was analyzed. At the same time, structural coefficient - a combined parameter which can quantify the overall microstructure of rock or soil was introduced to study Saprolite and the results are very positive. The study emphasized on the fractal characteristics of PSD and pore structure by applying fractal theory and method. With the results from thin section analysis and mercury injection, it was shown that at least two fractal dimensions Dfl(DB) and Df2 (Dw), exist for both PSD and pore structure. The reasons and physical meanings behind multi-fractal dimensions were analyzed. The fractal dimensions were used to calculate the formation depth and weathering rate of granite at Kowloon. As practical applications, correlations and mathematical models for fractal dimensions and engineering properties of soil were established. The correlation between fractal dimensions and mechanical properties of soil shows that the internal friction angle is mainly governed by Dfl 9 corresponding to coarse grain components, while the cohesion depends on Df2 , corresponding to fine grain components. The correlations between the fractal dimension, friction angle and cohesion are positive linear.Fractal models of PSD and pore size distribution were derived theoretically. Fragmentation mechanism of grains was also analyzed from the viewpoint of fractal. A simple function was derived to define the theoretical relationship between the water characteristic curve (WCC) and fractal dimension, based on a number of classical WCC models. This relationship provides a new analytical tool and research method for hydraulic properties in porous media and solute transportation. It also endues fractal dimensions with new physical meanings and facilitates applications of fractal dimensions in water retention characteristics, ground water movement, and environmental engineering.Based on the conclusions from the fractal characteristics of Saprolite, size effect on strength was expressed by fractal dimension. This function is in complete agreement with classical Weibull model and a simple function was derived to represent the relationship between them.In this thesis, the phenomenon of multi-fractal dimensions was theoretically analyzed and verified with WCC and saprolite PSD results, it was then concluded that multi-fractal can describe the characteristics of one object more accurately, compared to single fractal dimension. The multi-fractal of saprolite reflects its structural heterogeneity and changeable stress environment during the evolution history.

三峡库区滑坡的时空分布、成因及其预报模式

Landslides are widely distributed along the main stream banks of the Three Gorges Reservoir area. Especially with the acceleration of the human economic activities in the recent 30 years, the occurrence of landslide hazards in the local area trends to be more serious. Because of the special geological, topographic and climatic conditions of the Three Gorges areas, many Paleo-landslides are found along the gentle slope terrain of the population relocation sites. Under the natural condition, the Paleo-landslides usually keep stable. The Paleo-landslides might revive while they are influenced under the strong rainfall, water storage and migration engineering disturbance. Therefore, the prediction and prevention of landslide hazards have become the important problem involving with the safety of migration engineering of the Three Gorges Reservoir area.The past research on the landslides of the Three Gorges area is mainly concentrated on the stability analysis of individual landslide, and importance was little attached to the knowledge on the geological environment background of the formation of regional landslides. So, the relationship between distribution and evolution of landslides and globe dynamic processes was very scarce in the past research. With further study, it becomes difficult to explain the reasons for the magnitude and frequency of major geological hazards in terms of single endogenic or exogenic processes. It is possible to resolve the causes of major landslides in the Three Gorges area through the systematic research of regional tectonics and river evolution history.In present paper, based on the view of coupling of earth's endogenic and exogenic processes, the author researches the temporal and spacial distribution and formation evolution of major landslides(Volume^lOOX 104m3) in the Three Gorges Reservoir area through integration of first-hand sources statistics, .geological evolution history, isotope dating and numerical simulation method etc. And considering the main formation factors of landslides (topography, geology and rainfall condition), the author discusses the occurrence probability and prediction model of rainfall induced landslides.The distribution and magnitude of Paleo-landslides in the Three Gorges area is mainly controlled by lithology, geological structure, bank slope shape and geostress field etc. The major Paleo-landslides are concentrated on the periods 2.7-15.0 X 104aB.R, which conrresponds to the warm and wettest Paleoclimate stages. In the same time, the Three Gorges area experiences with the quickest crust uplift phase since 15.0X 104aB.P. It is indicated that the dynamic factor of polyphase major Paleo-landslides is the coupling processes of neotectonic movement and Quaternary climate changes. Based on the numerical simulation results of the formation evolution of Baota landslide, the quick crust uplift makes the deep river incision and the geostress relief causes the rock body of banks flexible. Under the strong rainfall condition, the pore-water pressure resulted from rain penetration and high flood level can have the shear strength of weak structural plane decrease to a great degree. Therefore, the bank slope is easy to slide at the slope bottom where shear stress concentrates. Finally, it forms the composite draught-traction type landslide of dip stratified rocks.The susceptibility idea for the rainfall induced landslide is put forward in this paper and the degree of susceptibility is graded in terms of the topography and geological conditions of landslides. Base on the integration with geological environment factors and rainfall condition, the author gives a new probabilistic prediction model for rainfall induced landslides. As an example from Chongqing City of the Three Gorges area, selecting the 5 factors of topography, lithology combination, slope shape, rock structure and hydrogeology and 21 kinds of status as prediction variables, the susceptibility zonation is carried out by information methods. The prediction criterion of landslides is established by two factors: the maximum 24 hour rainfall and the antecedent effective precipitation of 15 days. The new prediction model is possible to actualize the real-time regional landslide prediction and improve accuracy of landslide forecast.

句容海安区块热史、成烃史与二次生烃

Jurong -Hai'an block of lower Yangtz area is one of the important petroleum exploration area among the residual marine basins in the south China. In the history of the basin's evolution, the strongly compressing, napping, folding and deforming during Indosinian to Yanshan epoch resulted in destruction of the early formed petroleum pool. Therefore, the strategy exploration of the secondary hydrocarbon generation and later formation of petroleum pool was brought forward for petroleum exploration and planning in the study area..On the basis of tectonic and sedimentary as well as present-day thermal regime evolution, using vitrinite reflectance and apatite fission track data and the paleo-heat flow based method, the basin's thermal history is reconstructed and hence the strata's temperature history are obtained. In addition, the maturation histories of the main four sets of marine hydrocarbon source rocks in the block are calculated. Furthermore, taking the maturity in the end of early Cretaceous as the original maturity and according to the formulas fitted by the secondary hydrocarbon generation model, the secondary hydrocarbon generation potential of the four sets of source rock is evaluated.The results of thermal history reconstruction show that Jurong-Hai'an block was under an uniform thermal setting during the Caledonian to Hercynian period and characterized by middle heat flow (52~57rnW/ m2). The uniform thermal setting was divided during and after Indosinian to Yanshan epoch. Wuwei area of southern Anhui province was under the high heat flow setting(~90 mW/m2)between 236Ma and 137Ma; Jurong area of southern Jiangsu ,Huangqiao area and Subei basin reached its maximum heat flow of 90,84 and 78-82 mW/m2 at 101Ma,157Ma and 56Ma respectivelyThe study of secondary hydrocarbon generation shows that the upper Paleozoic and Triassic source rocks have excellent secondary hydrocarbon generation potential. Silurian source rock posses some secondary hydrocarbon generation. Cambrian source rock, however, nearly has no secondary hydrocarbon generation. Overall there are no advantages of secondary hydrocarbon generation in the southern area of Jiansu. The intensity of secondary hydrocarbon generation in North Jiangsu basin is definitely better than that in the southern area of Jiangsu.

龙滩水电站左岸边坡监测信息系统研制及其监测资料分析

Guangxi Longtan Hydropower Station is not only a representative project of West Developing and Power Transmission from West to East in China, but also the second Hydropower Station to Three Gorges Project which is under construction in China. There are 770 X 104m3 creeping rock mass on the left bank slope in upper reaches, in which laid 9 water inlet tunnels and some underground plant buildings. Since the 435m high excavated slope threatens the security of the Dam, its deformation and stability is of great importance to the power station.Based on the Autodesk Map2004, Longtan Hydropower Station Monitoring Information System on Left Bank has been basically finished on the whole. Integrating the hydropower station monitoring information into Geographic Information System(GIS) environment, managers and engineers can dynamically gain the deformation information of the slop by query the symbols. By this means, designers can improve the correctness of analysis, and make a strategic and proper decision. Since the system is beneficial to effectively manage the monitoring-data, equitably save the cost of design and safe construction, and decrease the workload of the engineers, it is a successful application to the combination of hydropower station monitoring information management and computer information system technology.At the same time, on the basis of the geological analysis and rock mass toppling deformation and failure mechanism analysis of Longtan engineering left bank slope, the synthetic space-time analysis and influence factors analysis on the surface monitoring data and deep rock mass monitoring data of A-zone on left bank slope are carried on. It shows that the main intrinsic factor that effects the deformation of Zone A is the argillite limestone interbedding toppling structure, and its main external factors are rain and slope excavation. What's more, Degree of Reinforcement Demand(DRD) has been used to evaluate the slop reinforce effect of Zone A on left bank according to the Engineering Geomechanics-mate-Synthetics(EGMS). The result shows that the slop has been effective reinforced, and it is more stable after reinforce.At last, on the basis of contrasting with several forecast models, a synthetic forecast GRAV model has been presented and used to forecast the deformation of zone A on left bank in generating electricity period. The result indicates that GRAV model has good forecast precision, strong stability, and practical valuable reliability.

黄土高原全新世风成沉积的岩石磁学性质

Chinese eolian deposits are especially suitable for the studies of paleoclimatic changes, environmental magnetism and remanence acquisition mechanisms. In the past two decades, many studies have documented their magnetic properties. However, some important problems, such as the origin of magnetic minerals, the mechanisms for enhancing magnetic susceptibility and the lock-in effect, remain debatable. Therefore, it is essential to detail the rock-magnetic properties of the eolian deposits. This study shows thermomagnetic analyses, petrographic measurements and soil chemistry methods can be combined to obtain a better understanding of the sequence of magnetic mineral alterations during thermal treatment and of the pedogenic mechanism responsible for the susceptibility enhancement. This helps to further develop the interpretation of paleoclimate records in the Holocene eolian deposits along a NW-SE transect of the loess plateau. A partial heating/cooling method and X-ray diffraction (XRD) analysis were performed on representative samples of the present-day loess, in order to investigate mineralogical changes during thermal treatment. The temperature-dependent susceptibility (TDS) and XRD results show complex alteration of magnetic phases during heating and cooling. The 300 ℃ susceptibility hump in heating curves might be due to the production of maghemite from less magnetic lepidocrocite during heating. Goethite is transformed into hematite when heating to above 300 ℃. The susceptibility decrease from 300 ℃ to 450 ℃ can be interpreted as the conversion of maghemite to hematite. This thermal instability makes it possible to quantatively estimate the maghemite contribution to the pedogenically-enhanced susceptibility in loess or paleosols. Minor occurrence of thermally-stable maghemite in the present-day loess is possible; nevertheless, the TDS measurements show that the degree of the thermally-induced alteration is closely related to pedogenesis. The TDS measurement and XRD analysis results demonstrate that although magnetite and hematite both exist in the Holocene loess eolian deposits and their modern source area, magnetite is the predominant contributor to magnetic susceptibility. Both magnetite and hematite are the primary carriers of the remanent magnetization. Fine-grained maghemite, mainly produced by pedogenesis, is significantly responsible for enhancement of the magnetic susceptibility in the Chinese loess and paleosols. Since the degree of oxidation of magnetite grains depends on climate, the presence of maghemite has paleoclimatic significance, and variations in climate could be reflected as variations in the amount of low-temperature oxidation. If that is the case, the TDS curves can be used to compare the effects of climate at different sampling sites. The TDS results along the studied NW-SE transect suggest that stronger pedogenesis results in higher content of maghemite and greater susceptibility decrease during thermal treatment. This behavior seems to indicate that the final product of pedogenic magnetite in Chinese loess and paleosols is maghemite, which makes significant contributions to the enhanced magnetic susceptibility of Chinese eolian deposits. It is interesting to note that the 510 ℃ Hopkinson/alteration peak is larger in the present-day loess than in the black loam for each section. Obiviously, the Hopkinson/alteration peak of the Holocene eolian deposits is closely related to the degree of pedogenesis, which is a function of climate, and thus the peak itself could be a useful climate indicator. There are three effects that may be important in producing this trend. First, low-temperature oxidation preferentially affects the finer single-domain magnetites responsible for the Hopkinson peak, which is therefore suppressed in the more oxidized loams. Second, the possible production of uniaxial magnetite with shape anisotropy can also lead to a relatively muted Hopkinson peak. There is, additionally, a third alternative, and the one preferred here, that the natural alteration processes involved in pedogenic susceptibility enhancement have probably depleted the supply of iron-bearing precursor phases, so that less new magnetite is formed on heating. In summary, the TDS method is very reliable and highly sensitive in detecting magnetic phase changes in eolian deposits during thermal treatment, which are closely related to pedogenic processes. Thus, the studied NW-SE transect clearly exhibits paleoclimatically-induced mineral- and rock-magnetic variations. It is suggested that TDS can be used as a new method for the analysis of pedogenesis and climatic change.

Isotope Geochemistry of Gold Ore Deposits in the Gezhen Shear Zone, Qiongxi, Hainan Island

Gold deposits hosted in the Gezhen shear zone at Qingxi, Hainan Island occur in the Precambrian metamorphic rock series and are regionally developed in the N-E direction along the tectonic zone. From northeast to southwest are distributed the Tuwaishan-Baoban gold mining district, the Erjia gold mining district and the Bumo gold mining district, making up the most industrially important gold metallogenesis zone on the Hainan Island. Isotope geochemical studies of the typical gold deposits in this metallogen

Sedimentary-volcanic tufts formed during the early Middle Triassic volcanic event in Guizhou Province and their stratigraphic significance

The sedimentary-volcanic tuff （locally called ＂green-bean rock＂） formed during the early Middle Triassic volcanic event in Guizhou Province is characterized as being thin, stable, widespread, short in forming time and predominantly green in color. The green-bean rock is a perfect indicator for stratigraphic division. Its petrographic and geochemical features are unique, and it is composed mainly of glassy fragments and subordinately of crystal fragments and volcanic ash balls. Analysis of the major and trace elements and rare-earth elements （ REE）, as well as the related diagrams, permits us to believe that the green-bean rock is acidic volcanic material of the calc-alkaline series formed in the Indosinian orogenic belt on the Sino-Vietnam border, which was atmospherically transported to the tectonically stable areas and then deposited as sedimentary-volcanic rocks there. According to the age of green-bean rock, it is deduced that the boundary age of the Middle-Lower Triassic overlain by the sedimentary-volcanic tuff is about 247 Ma.

吐哈盆地砂岩型铀矿含矿主岩沉积体系及地球化学特征

吐哈盆地位于哈萨克斯坦板块的东端，与邻国盛产可地浸砂岩型铀矿的中新生代盆地处于统一类型的板块，同属中亚构造－成矿域。吐哈盆地也是我国可地浸砂岩型铀矿的第二个勘查基地。对吐哈盆地砂岩型铀矿的主要含矿建造－中下侏罗统水西沟群沉积体系类型的研究，将有助于区内对砂岩型铀矿成矿和容矿的主要沉积建造的地质认识。而对含矿主岩的地质地球化学研究，则能为区内砂岩型铀矿的成矿作用研究提供依据。在对吐哈盆地形成演化历史分析的基础上，通过对早中侏罗世盆地沉积建造的资料综合、野外调查和室内研究，针对可地浸砂岩型铀矿的地质特征、形成条件等，围绕建造-构造、构造-改造、改造-成矿作用的关系等问题，从区域地质构造背景、沉积体系类型分析和构造变形特征等宏观研究入手，到对钻孔岩芯的微观分析研究，特别是在对十红滩铀矿区的重点解剖的基础上，结合光谱信息提取与增强技术的应用，甄别含矿建造的地质特征及其时空分布格局，对吐哈盆地砂岩型铀矿主含矿岩系的沉积体系类型及其地球化学特征的研究得到以下认识： 1. 吐哈盆地中下侏罗统水西沟群的沉积体系类型包括：冲积扇沉积、辫状河沉积、辫状三角洲沉积系和湖泊沉积。而吐哈盆地十红滩铀矿区砂岩型铀矿的含矿主岩的沉积体系类型则为源自南部觉罗塔格山的辫状三角洲沉积体系。 吐哈盆地十红滩铀矿区砂岩型铀矿的含矿主岩是在盆地短轴方向上的局部性水动力条件和沉积环境下形成的一套以近源短距离搬运形成的粗碎屑沉积建造。这套建造及其沉积体系类型与整个湖盆地的泛湖沉积作用在时间和空间上发生叠置。正是因为不同沉积体系类型在时间和空间上发生叠置，从而导致中下侏罗统的地层总体走向与砂砾岩等粗碎屑沉积体的整体走向有显著的差异。沉积建造的这种空间展布格局对砂岩型铀矿的形成具有重要的控制作用。总体上，这一特点决定了与砂岩型铀矿成矿作用有关的含铀流体的运移方向、规模和铀成矿作用的区域分布和空间展布。 2. 鉴于吐哈盆地中下侏罗统不同沉积体系类型的区域分布和空间展布特征，以及内陆沉积盆地的沉积作用具有相似的沉积格局，建议在查明有利于砂岩型铀矿成矿的砂体所属沉积体系类型的基础上，按沉积体系类型划分沉积单元进行地层的划分与对比，将这一方法运用于内陆沉积盆地的地层划分对比，便于对砂岩型铀矿成矿的最基本控制因素“砂体”的宏观控制，从而为砂岩铀矿成矿作用分析、区域成矿预测和资源勘查提供直接依据。因此，正确区分泛湖水动力体系的区域性沉积系统及其沉积体系和局部性水动力体系的局域性沉积系统及其沉积体系，不仅具有地层学上的意义，更具有实际应用价值。 3. 吐哈盆地艾丁湖斜坡带中下侏罗统的构造变形特征存在明显的空间差异。主要表现为：在横向上，沿艾丁湖斜坡带由东往西不同地段构造形迹不同；在纵向上，不同层位的变形特点各异。总体表现为：以十红滩铀矿区为中心，往东以水西沟群上部第三岩性段（J2x3）的构造反转、逆冲而出现断裂构造为主。中部十红滩一带以水西沟群下部第一层位（J2x1）的宽缓褶皱为主。往西以西山窑组中部第二岩性段（J2x2）较为强烈的地层褶皱为特征。说明中下侏罗统形成之后，遭受过区域性的构造改造。 4. 对钻孔砂岩样品的岩石学研究和显微构造观察表明，十红滩铀矿区含矿砂体最为常见的碎屑有石英、长石（钾长石为主，少量斜长石）、云母以及花岗质岩屑、变质岩岩屑、少量火山岩岩屑，偶见沉积岩岩屑；砂岩中的填隙物主要有高岭石、水云母、绿泥石以及碳酸盐类矿物和少量铁质矿物。胶结物通常为碳酸盐、硅质及一些铁质物质。胶结类型主要有基底式胶结、孔隙式胶结和压嵌式三种类型。且砂岩中存在多期次构造－流体改造的迹象。在整体上，含矿砂体与无矿砂体构造－流体改造的类型相近，但其改造程度各不相同。含矿砂体主要表现为微构造裂隙发育，并有多期次硅质、碳酸盐充填和交代、溶蚀现象。含有石英、高岭石、绿泥石等新生矿物；不含矿砂体则以绿泥石化普遍，碳酸盐化作用强为主要特征。 样品中的蚀变矿物出现微晶黑云母、绿泥石－绿帘石－石英共生矿物组合，出现脆韧性显微构造变形等，预示这套含矿建造曾经遭受过一定程度的构造热变质作用。 5. 钻孔岩芯砂岩样品的稀土、微量元素地球化学特征表明，十红滩铀矿区的砂岩具有统一的物质来源。其稀土配分型式与蚀源区花岗质岩石的稀土配分型式相似。区域氧化作用造成砂体矿物蚀变的同时，也造成砂岩中稀土元素的分馏，且氧化蚀变越强，稀土元素的分馏作用也越明显。与晚元古代黑色页岩平均值相比，十红滩铀矿床钻孔中砂岩Zr和Hf的含量普遍偏高，特别是Hf，大部分样品中的Hf含量均高于晚元古代黑色页岩平均值。 zk32-11-2、zk96-4、zk96-7、zk80-6四个钻孔岩芯的砂岩样品稀土元素特征值δEu，在不同深度的各砂岩中变化较大。无论是单孔还是在钻孔之间，δEu值都表现为跳跃式的变化，且整体上分流河道砂岩中δEu值偏低。相对于δEu值，δCe和TE（1，3）值似乎表现出一定的变化规律。总体上表现为在与泥岩、泥质粉砂岩呈互层产出的三角洲前缘砂岩中，具有较为相近的δCe和TE（1，3）值。而分流河道砂体的δCe和TE（1，3）值相对变化较大，且整体上数值偏小。这些样品稀土元素特征值δEu、δCe和TE（1，3）所表现出的特点与砂体的沉积体系类型分析以及相应的岩石学特点基本吻合。说明不同沉积系统的各类沉积体系，不仅在时空展布上存在差异，砂体的结构及物质组成也存在一定的差异。 6. 根据中下侏罗统不同沉积体系类型在吐哈盆地全域范围的时空配置以及遥感地学的区域氧化还原条件分析，并与十红滩铀矿区相比较，吐哈盆地西部阿拉沟口、柯尔碱一带和了敦隆起西缘的鄯善－小草湖一带，具有和十红滩铀矿区类似的沉积历史、建造特征和区域氧化－还原条件，可以作为进一步开展砂岩型铀矿成矿预测和资源勘查的地段。 7．吐哈盆地的砂岩型铀矿与中亚各国重要的可地浸砂岩型铀矿在盆地类型、含矿主岩的沉积体系、含矿主岩的时代等方面有一定的差异，而其盆地类型及含矿主岩的沉积体系与美国怀俄明地区的可地浸砂岩型铀矿，特别是温得河盆地的砂岩型铀矿的特点较为相似。 8. 遥感信息提取和地学分析，可以提供区域性氧化－还原环境的区域分布信息，甚至可以为寻找潜在有利含矿砂体的空间展布提供依据；借助GIS平台，充分利用3S技术的集成与应用，可望为北方干旱地区可地浸砂岩型铀矿成矿条件分析、远景预测和找矿靶区的快速圈定乃至进行资源勘查的实际工作部署提供新的可操作技术平台。 在取得这些认识的同时，也深感还有不少问题需要进一步补充工作和深入探讨。特别是有关砂岩型铀矿的矿物学和地球化学方面尚有许多现象目前还不能给予很好的解释；对于存在的多次构造－流体的改造作用机理、多期次构造－流体活动之间的相互联系及其与铀矿化的关系；对流体的性质、来源和流体与砂体之间的相互作用关系等还有大量工作需要补充和深入。虽然已获得大量有关砂岩的稀土、微量元素的数据，但对这些数据的处理方法有限，对于其反映的与区内砂岩型铀矿成矿作用有关的信息有待进一步挖掘。另外，由于未能采集到砂岩铀矿的矿石样品，针对铀矿床方面的工作未能开展。

贵州遵义早寒武世黑色岩系地球化学研究

华南早寒武世黑色岩系赋存Ni-Mo-PGE、V-U、Se、磷块岩、重晶石（毒重石）、石煤等多种矿产，富含As、Se、Hg、Gd、Pb等多种对生态环境有害的元素，产出小壳、海绵骨针、大型双壳节肢动物等多种古生物化石，因而它在矿产勘查、环境保护、地史古生物等方面具有重要的研究意义。然而，目前这些方面的研究还处于积累阶段，许多科学问题还没有得到很好地解决，一方面是因为华南早寒武世地层划分不统一，缺乏精确的年代学数据；另一方面是因为沉积地球化学研究程度不高。为了深入认识早寒武世古海洋的环境特征和演化历史，促进统一的早寒武世地层的建立，本论文选择了扬子地台上的贵州遵义早寒武世中南村黑色岩系剖面为对象，进行了系统的沉积地质学和地球化学研究，取得了如下几个方面的重要认识： （1）中南村黑色岩系剖面从下到上由磷块岩层、富黄铁矿粘土岩层、“破碎层”、硅质(页)岩层、钒矿层、含粉砂黑色页岩层、镍钼矿层、含化石黑色页岩层、黑色页岩层和粉砂质页岩层10个岩层组成，具有两个明显的特征，一是沉积环境发生了变化，从剖面底部远岸的、砂质输入较少的远海环境逐渐过渡到剖面顶部近岸的、砂质输入较多的近海环境；二是剖面下部的地质活动相对较丰富，除了火山成因“破碎层”和热水成因硅质岩外，还含有三个重要的硫化物矿化层：富黄铁矿粘土岩层、钒矿层和镍钼矿层。 （2）磷块岩主要由碳氟磷灰石和自生石英组成，含少量自生重晶石和含钒伊利石；磷灰石具有“老磷块岩”型REE配分曲线：∑REE高，Ce明显负异常，MREE富集，HREE亏损；磷灰石的硫酸盐硫同位素较大，平均为38.1‰。由此可推测，磷块岩是在分层海洋的上升洋流区的氧含量最小带的沉积物-水界面上形成的，沉积、成岩过程中吸收了海水中的硫酸盐和REE；磷块岩中磷灰石所记录的早寒武世海水硫酸盐的硫同位素组成为36.6±1.6‰。 （3）黑色硅、泥质岩中，微量元素Ba、Ni、U、V和Mo含量总体上较高，元素/Sc值与有机碳/Sc值之间的相关性明显；有机碳同位素组成较低，为-34.3‰～-31.2‰，表明早寒武世海洋可能为具有分层结构、古生产力水平较高、静海缺氧环境等特点的古海洋。剖面上，元素/Sc值向上逐渐降低，13Corg向上变大，有机质中的REE组成向上变为海水型，表明从早期到晚期古生产力水平和缺氧程度在不断减弱。 （4）微量元素U/Sc值、Mo/Sc值，有机碳同位素组成，有机质中的REE特征等参数在硅质岩、“破碎层”、钒矿层、镍钼矿层中均显示明显的异常，暗示它们的形成与热水/热液活动有关。镍钼矿层处的地球化学异常与古海洋历史性调整有关，可作为“前三叶虫统”分阶的标志，其它层位的异常特征可以作为区域地层对比的标志。

高温高压下岩石部分熔融及熔体形态学研究

熔体形态学作为现代岩石学的前沿领域之一，其主要研究矿物颗粒之间熔体形态特征、连通性以及与周围矿物的相互作用关系。该学科在我国还不被广大地学工作者所熟悉。本论文以斜长角闪岩为初始物料，在850-1100℃和2.0-4.0 GPa条件下，进行了岩石的部分熔融实验，并对作为实验产物的熔体进行了形态学方面的研究。同时就目前形态学研究的基础理论和实验方法作了初步介绍。 利用YJ－3000吨六面顶高压装置，我们以天然的块状斜长角闪岩为样品，在高温高压条件下进行了斜长角闪岩的脱水部分熔融实验，测量了熔体与矿物相接触时所形成的二面角。结果表明： 1、熔体的形态分布与熔融程度具有明显依赖关系，当熔融程度小于5%时，熔体被矿物颗粒分隔开来，以熔块的形式相互独立；当熔融程度大于5%时，薄膜状或管状熔体沿矿物颗粒边缘形成一个相互连通的熔融网络。 2、当熔体相互隔离时，二面角平均值大于60°；当熔体相互连通时，二面角平均值小于60°。在熔体相互连通的测量实验中，英安质和安山质成分的熔体与石榴子石的二面角分布在56－58°之间，与单斜辉石的二面角分布在50－53°之间。 3、根据界面化学理论推导表面张力和界面能的最小化是推动熔体连通的两个驱动力。 4、二面角大小受体系温度、压力及物质组成等物理化学条件的影响，随着温度升高，固－液界面的表面张力减弱，二面角减小，熔体越容易相互连通。 5、通过对二面角的原位测量，不仅可以判断熔体的相互连通性，还能反演熔体的熔融过程。

高温高压下部分熔融岩石和岩石玻璃弹性波速研究

人类对地球深部结构的认识主要依赖于天然地震的观测资料，高温高压下矿物、岩石和岩浆玻璃的弹性波速测量，是对野外地震波探测资料进行物质反演的重要依据，也为建立地球内部结构模型和地球动力学研究提供重要的实验数据。大量研究证实，高温高压下岩石的部分熔融将形成地震波低速层。然而，前人的研究中，多以岩石的纵波波速（Vp）测量结果来讨论区域地壳结构和低速层的成因，而且很少对实验过程中的中间产物进行观察分析。另一方面，由于玻璃在高温高压下具有特殊的弹性性质，一些科学家推测地球内部岩石的非晶质化也将导致地震波低速层形成。但目前这一推测尚缺乏充分的实验数据支持。为此，作者依托YJ-3000吨大腔体高压实验技术平台，利用脉冲反射法和透射－反射法，完成了： （Ⅰ）三江地区花岗岩和角闪斜长片麻岩在最高压力2.0GPa、最高温度1200℃下的纵波波速（Vp）和最高温度600℃下的横波波速（Vs）研究，并通过岩石物态变化过程中的取样实验，综合探讨岩石中矿物脱水、固－固相变、部分熔融对其弹性波速的影响。获得以下主要结论： ① 花岗岩和角闪斜长片麻岩的Vp和Vs随压力及温度的变化趋势基本一致。室温下岩石的Vp和Vs随压力升高而升高，岩石波速具明显的各向异性，而且其各向异性随压力增大到约0.5GPa后逐渐趋于一恒定值； ② 恒定压力下，岩石的Vp和Vs首先随温度升高近线性缓慢降低，当750℃ 950℃后，石英相变完成，岩石的波速由于熔体含量增加又快速降低； ③ 高温高压下岩石的Vp和Vs研究显示了对三江地区地壳结构一致的约束结果，即该区花岗岩主要分布在上地壳，而角闪斜长片麻岩从上地壳底部到中地壳底部均有分布，这一结果与前人利用Vp研究建立的该区地壳模型基本一致； ④ 在三江地区中上地壳高石英含量的岩石中，石英的α－β相变是地壳地震波低速层形成的主要因素，而随岩石中石英含量的变化，高温高压下岩石的部分熔融及岩石的波速各向异性也可能形成低速层。 （Ⅱ）化学成分从基性到酸性的7种岩石的熔体玻璃在1.0GPa和2.0GPa，最高温度1000℃下的Vp研究和最高温度730℃下的Vs研究。获得以下主要结论： ① 与岩石波速随压力增大而增大不同，室温、0.4－2.0GPa压力下，除两种基性岩石（正长辉石岩和粗面玄武岩）的熔体玻璃外，其它5种中酸性岩石的熔体玻璃的Vp均随压力增大而减小，而这7种玻璃的Vs全部随压力增大而减小。而且，玻璃波速随压力增加而异常降低的幅度随样品中SiO2含量的增高逐渐增大； ② 恒定压力下，随实验温度升高，各种玻璃的弹性波速缓慢降低。当温度高于玻璃转变温度Tg后，玻璃弹性波速的温度系数（∂V/∂T）增大约3倍以上； ③ 研究证实了一种新的地震波低速层成因模式，即上地幔岩石中如果含有超过10vol％的玄武岩玻璃，将会形成地震波低速层；假如下地壳基性岩石中中酸性非晶质体含量超过20vol％，也可能导致地壳低速层的形成。

东营凹陷火成岩发育区油气生成与成藏模式研究

该文提出了一套了适用于胜利油区火成岩油气藏成藏机理研究的综合研究方法.通过地质和地球物理资料分析,查明了火成岩的时空分布规律,应用岩石学和地球化学原理方法确定了火成岩-烃源岩共生组合体的岩性、岩相及其形成的构造背景.重点研究了火成岩-烃源岩共生组合体的地质地球化学特征及火山物质与有机质的相互作用,特别是用模拟实验的方法对火山来源的过渡金属元素在有机质生烃过程中催化作用进行深入研究,此外还讨论了火成岩-烃源岩组合体中有机质生烃的加氢作用,烃源岩有机酸对火成岩的溶蚀改造作用等.最后,应用油气成藏动力学的研究方法阐明了玄武岩-烃源岩和辉长岩-烃源岩组合体油气藏的成藏机制,建立了两种油气成藏模式.