贝尔凹陷与塔南凹陷下白垩统铜钵庙组南屯组油气储层特征及孔隙度控制作用

早白垩世铜钵庙-南屯组的火山岩和砂岩是中国海拉尔盆地贝尔凹陷和蒙古国塔木察格盆地塔南凹陷的主要油气储层.其中:铜钵庙组储层主要由火山碎屑岩组成;南屯组储层以砂岩为主,其次为火山碎屑岩.在铜钵庙组的火山碎屑岩中,贝尔凹陷主要为凝灰岩,塔南凹陷主要为沉凝灰岩和凝灰质砂岩.镜质体反射率和最高热解温度数据表明,成岩阶段主要为中成岩阶段A期.铜钵庙组-南屯组储层的孔隙类型主要为次生孔,其次为原生孔,属中低孔、特低渗型储层.贝尔凹陷和塔南凹陷均发育2个异常高孔隙带,储层孔隙度主要受储层岩石类型、沉积相和成岩作用控制.     

水库诱发地震作用下三峡库区基岩地震动模拟

使用接触单元建立三峡库首区断裂展布有限元模型,使用确定性的设定地震方法,为时程分析提供合理的水库地震动输入。二维有限元水平基岩地震动模拟结果表明,九畹溪断裂发生M5.5级构造型水库地震时,三峡大坝场址水平向基岩PGA为175 Gal;而高桥断裂发生M5.5级地震时,巴东县城场址水平向基岩PGA为303 Gal。断裂带两侧PGA出现明显的不连续特征,场址基岩地震动参数的计算有必要考虑该影响。     

渤海海冰微波散射特性研究

Microwave remote sensing has become the primary means for sea-ice research, and has been supported by a great deal of field experiments and theoretical studies regarding sea-ice microwave scattering. However, these studies have been barely carried in the Bohai Sea. The sea-ice microwave scattering mechanism was first developed for the thin sea ice with slight roughness in the Bohai Sea in the winter of 2012, and included the backscattering coefficients which were measured on the different conditions of three bands(L, C and X), two polarizations(HH and VV), and incident angles of 20° to 60°, using a ground-based scatterometer and the synchronous physical parameters of the sea-ice temperature, density, thickness, salinity, and so on. The theoretical model of the sea-ice electromagnetic scattering is obtained based on these physical parameters. The research regarding the sea-ice microwave scattering mechanism is carried out through two means, which includes the comparison between the field microwave scattering data and the simulation results of the theoretical model, as well as the feature analysis of the four components of the sea-ice electromagnetic scattering. It is revealed that the sea-ice microwave scattering data and the theoretical simulation results vary in the same trend with the incident angles. Also, there is a visible variant in the sensitivity of every component to the different bands.For example, the C and X bands are sensitive to the top surface, the X band is sensitive to the scatterers, and the L and C bands are sensitive to the bottom surface, and so on. It is suggested that the features of the sea-ice surfaces and scatterers can be retrieved by the further research in the future. This experiment can provide an experimental and theoretical foundation for research regarding the sea-ice microwave scattering characteristics in the Bohai Sea.     

Dynamic process analysis of the Niumiangou landslide triggered by the Wenchuan earthquake using the finite difference method and a modified discontinuous deformation analysis

The Niumiangou landslide was the largest landslide triggered by the 2008 Wenchuan earthquake, which was significantly affected by the amplification effect of seismic acceleration. The ringshear experiments indicated that the materials in the source area of the Niumiangou landslide were subjected to friction degradation under a big shear displacement, which may result in rapid movement of the landslide. In order to better understand the landslide movement and study the effect of the friction degradation on movement mechanisms, the dynamic process of Niumiangou landslide was simulated with a new numerical method, which combines the finite difference method(FDM) and the discontinuous deformation analysis(DDA). First, the FDM was used to study the initiation time, amplification effect and velocity of the landslide. Afterwards, these initiation velocities were applied to the blocks in the DDA model by corresponding coordination in the FDM model. A displacementdependent friction model of the sliding surface was incorporated into DDA code to further understand the kinetic behavior of the landslide. The results show that the displacement-dependent friction strongly decreases the friction coefficient of sliding surface under a big displacement, which can obviously promote the run-out and velocity of landslide. The model output well matches the topographic map formed by the landslide. This implies that the proposed model can be applied to the simulation of earthquake-induced landslides with amplification effect, and the friction degradation model is important to clarify the movement mechanism of high-speed and long-distance landslides.     

北部湾盆地涠西南凹陷断裂系统成因的砂箱实验研究及启示

北部湾盆地涠西南凹陷的断裂系统十分复杂,为了揭示其成因机制,在三维地震资料构造解析的基础上,应用砂箱物理模拟技术,对涠西南凹陷的形成机制进行了系统研究.结果表明,南北向的不协调伸展作用实验模型能够成功地模拟涠西南凹陷晚始新世以来复杂的断裂系统,断裂系统的主体特征在这一实验模型中均得到了很好的再现.涠两南凹陷复杂的断裂系统是在基底先1竽构造基础之上,在递进变形过程中逐渐形成的,其裂陷期(晚始新世一渐新世)断裂系统是在一个伸展期内形成(南北向伸展)、并非是多期构造叠加变形的结果.这一认识不但能够有效地指导涠西南凹陷三维地震资料的精细构造解释,同时也能够为南海周缘盆地的形成和演化研究提供借鉴.     

墨西哥湾天然气水合物矿产资源预测模型及其应用

墨西哥湾是世界上研究天然气水合物较深入的海区,调查资料丰富,已在50多处采集到天然气水合物样品,具备建立天然气水合物矿产资源预测模型的条件。选择34处已知天然气水合物矿点和34处已知无矿点作为训练区,建立矿点存在与否的预测模型。模型的相关系数值表明墨西哥湾天然气水合物与盐底辟关系密切。将该模型应用于整个墨西哥湾北部,初步获得了天然气水合物存在可能性概率分布图;概率大于0.7的预测单元包含已知矿点中的30个,利用该阈值圈定了墨西哥湾天然气水合物潜在资源分布区。     

BTEX anomalies used as indicators of submarine oil and gas reservoirs

It is a conventional method for petroleum prospecting to generally use paraffin hydrocarbon as basic indexes of oil and gas. This conventional geochemical technology, however, shows some limits in the prospecting as paraffin is vulnerable to influences from human and biologic activities. Consequently, BTEX (short for benzene, toluene, ethyl benzene and xylem, which are direct biomarkers) among aromatic hydrocarbon series has been taken into account for the oil and gas prediction. Domestic and foreign study results demonstrate that BTEX is hardly disturbed and can well indicate oil and gas reservoirs. Based on measured data from a South China Sea area, the present authors have used self-developed visual assessment software for petroleum prospecting has been used to process data, strip background anomalies, and outline significant BTEX anomalies. By comparison with stratigraphic profiles of the target area, it is confirmed that BTEX is a good indication of marine oil and gas during the petroleum prospecting.     

Two-stage collision-related extrusion of the western Dabie HP–UHP metamorphic terranes, central China: Evidence from quartz c-axis fabrics and structures

The western Dabie orogen (also known as the Hong'an block) forms the western part of the Dabie–Sulu HP–UHP belt, central China. Rocks of this orogen have been subjected to pervasive ductile deformation, and include numerous quartz schists and felsic mylonites cropping out in ductile shear zones. Quartz textures in these mylonites contain important clues for understanding the movement sense of late-collisional extrusion and exhumation of high-pressure–ultrahigh-pressure (HP–UHP) rocks from the lower crustal level to the upper crustal level during Middle Triassic and Early Jurassic. The orientation and distribution of quartz crystallographic axes were used to confirm the regional shear sense across the orogen. The asymmetry of c-axis patterns consistently indicates top-to-the-southeast thrusting across the orogen in early structural stages. Later stages of deformation show different senses of movement in northern and southern parts of the orogen, with top-to-the-northwest sinistral shearing recorded in rocks north of the Xinxian HP–UHP eclogite-facies belt, and top-to-the-southeast dextral shearing south of the same unit.Based on our study on quartz c-axis fabrics and marco- to micro-scale structures, simultaneous southeastward shearing within a large part of the orogen and normal faulting north of the Xinxian HP–UHP unit is explained by upward extrusion in early stages of deformation. The extrusion process has been attributed to syn- and late-collisional processes, accounting for some earlier deformation in the western Dabie orogen such as metamorphic sequences around the core of the Xinxian HP–UHP eclogite-facies unit. Much higher pressure of deformation is also indicated in the aligned glaucophane and omphacite from blueschist and eclogite in the field. An orogen-parallel eastward extrusion of the Xinxian HP–UHP eclogite-facies unit, however, occurred diachronously in later stages of deformation. Therefore, a tectonic model combining an early upward extrusion with a later eastward extrusion is presented. Two different stages and types of extrusion for exhumation of HP–UHP rocks are suitable to all of east central China. Geochronological data shows that the first, upward extrusion occurred during Middle Triassic, the second, eastward extrusion occurred during Late Triassic to Early Jurassic. These two extrusions are correlative with two stages of rapid exhumation of the Dabie HP–UHP rocks, respectively. These two-stage late-collisional (Middle Triassic to Early Jurassic) extrusion events bridge the gap between syn-collisional (Early to Middle Triassic) vertical extrusion and post-collisional (Cretaceous) eastward-directed lateral escape and provide vital clues to understanding the more detailed processes of exhumation of HP–UHP rocks.     

基于动三轴试验的层间错动带动孔压特性及能量分析

2008年汶川地震触发的大光包滑坡滑带形成背景是渗水层间错动带,该带强度变化是决定滑坡启动的主要因素,动孔压发展是土体材料强度劣化的根本原因,故基于系列室内动三轴试验研究该带材料孔压特性。结果表明,动载下层间错动带材料孔压快速增长,循环剪应力比越大,孔压增长越快,不同荷载条件下应变达到5%时动孔压比等于1,材料液化,根据动孔压比与振次比曲线的拟合关系提出幂函数应力模型。从能量角度描述层间错动带材料孔压增长特性,揭示出循环剪应力比对累积能量耗损与动孔压比曲线影响较小而围压对其影响较大,并进一步提出孔压增长的能量模型。     

西施舌外套膜蛋白质组双向电泳体系的构建

建立了西施舌(Coelomactra antiquata)外套膜蛋白质组的双向凝胶电泳体系,比较分析了不同pH梯度胶条、水化条件的优化及不同染色方法对双向电泳结果的影响.结果表明:用pH 4～7的非线性胶条,水化时加上除盐步骤,采用硝酸银染色,即可获得高分辨率、高重现性的双向电泳图谱,为进一步研究西施舌外套膜蛋白质的组成奠定了基础.