库车坳陷东部白垩系沉积体系分析及有利油气勘探区带预测

克拉2大气田的发现,展示了库车坳陷白垩系良好的油气勘探潜力。通过对库车坳陷东部野外露头、钻井资料以及地震剖面的综合分析,对坳陷东部白垩系的沉积体系类型及其分布特征进行了系统的研究。结果表明:研究区白垩系发育湖泊体系、扇三角洲体系、辫状河三角洲体系和三角洲体系等四种沉积体系类型;白垩系岩相古地理经历了早、中、晚期的演化,早期发育了以扇三角洲体系为主的沉积环境,中期形成了大范围的浅湖环境,晚期以三角洲平原相环境为特色;平面上,白垩系岩相古地理南北分带明显,具有南北双向提供物源的特征,粗碎屑分布在坳陷较陡的北侧。库车坳陷东部储层主要由三种三角洲体系砂体和滨岸沙坝砂体构成,砂体厚度大,分布广,储集条件好。     

Siltation Prediction for Navigation Channels and Harbour Basins on Muddy Beach

- This paper, after briefly reviewing the experimental research on sediment transport on muddy beach since the 1950s, improves and perfects the method for forecasting siltation in navigation channels and harbour basins which was first put forward in China by the authors. In consideration of silty sediment and sand, some factors in forecasting methods have been changed and modified. Consequently, the modified methods can be used either to compute siltation in navigation channels and harbour basins on muddy beach or to compute siltation and scouring in navigation channels and harbour basins on both silty beach and sandy beach. The verification of field data from eleven large, medium and small natural harbours shows a good agreement between the forecasting by the modified method and the natural conditions. Finally, the paper deals with the rational utilization of water area after the construction of the West Dyke in Lianyungang, the maintenance of water depth of the navigation channel at the entrance, siltation distribution, siltation in the navigation channel and harbour basin for ships of 100 thousand tonnnage. Results once again prove that the prospect of constructing Lianyungang Harbour into a deepwater harbour is bright.     

东营凹陷牛庄地区沙三段层序地层分析

山东济阳坳陷东营凹陷牛庄地区沙三段层序地层分析是在三级层序划分的基础上,通过对沉积体系发育特征和气候旋回单元的识别和解剖,建立了高精度层序地层单元的基本构型。气候旋回包含了从干旱枯水期到潮湿湖泛期的完整过程,沉积响应为受湖平面变化、沉积物供给等因素控制的多种方式叠置的湖底扇和前积体等,多期气候旋回叠合构成了湖泊层序的基本面貌。通过气候旋回的识别,可以对不同级别层序间的包含关系,以及高精度层序的内部构成进行分析和讨论。     

In-Situ Observation of Fluid Mud in the North Passage of Yangtze Estuary, China

Observations of fluid mud were made in the lower North Passage of the Yangtze Estuary in February 2000, on 10 -11 August 2000, on 30 - 31 August 2000 (after two strong typhoons), on 21 - 24 August 2000 (neap tide) and on 3 -6 September 2000 (mean tide) respectively. In situ data show that the fluid mud in this area consists of fine cohesive sediment (median size 7.23 μm). The formation and movement of fluid mud varied during the neap-spring and flood-ebb tidal cycle. Observations suggest that fluid mud phenomena in this area may be categorised in a three-fold manner as slack water, storm and saltwedge features. The thickness of the fluid mud layer of slack water during the neap tide ranged from 0.2 to 0.96 m, whereas during the mean tide, the thickness ranged from 0.17 to 0.73 m, and the thickness of the fluid mud layer was larger during slack water than at the flood peak. Shoals cover an area of 800 km^2 with a water depth smaller than 5 m. Erosion of these extensive intertidal mudflats due to storm action provides an abundant sediment source. This is particularly significant in this estuary when the tidal level is lower than 5 m. The lower North Passage is a typical zone of saltwater wedging, so the saltwedge fluid mud has the most extensive spatial range in the estuary.     

Research on Characteristics of Density Current Under the Action of Waves

In this paper,the characteristics of density current under the action of waves are describedwith the help of flume experiment and theoretical analysis.The study shows that turbid water under the ac-tion of the waves can present three types of motion,i.e.significant stratification,fragile stratification andstrong mixing.The motion of turbid water presents significant stratification when(H/D)/△ρ/ρ~(1/2)≤4.5,generally this state is known as density current.The formulas of motionvelocity,thickness,and discharge of density current moving on horizontal bottom are derived by use of ba-sic equations such as momemtum equation,equation of energy conservation and continuity equation offluid.The time-average velocity and the thickness of density current under the action of waves have a rela-tionship with such parameters as relative density(△ρ/ρ),wave height(H),and water depth(D).Whenthese parameters are determined,the time-average thickness and motion velocity of density current are al-so determined.The relat     

中国西北地区石炭纪岩相古地理?

根据研究区实测露头剖面沉积构造、岩矿、沉积地球化学、粒度分析、古流向资料、重矿物及沉积相的综合研究，结合地层、古生物、区域岩性资料等，对研究区石炭纪岩相古地理特征进行了分析。研究区早石炭世有5个古陆，即阿勒泰古陆南准噶尔古陆、敦煌-走廊古陆、阿拉善古陆、陇西古陆；有10个沉积相区，即库马苏滨浅海相区、布尔津-富蕴滨浅海相区、博格达滨浅海区、北准噶尔深海-半深海相区、北天山半深海-深海相区、克拉美丽冲积扇-湖泊相区、克拉玛依冲积扇-湖泊区、南天山-北祁连滨浅相区、柴达木碳酸盐台地相区、中祁连滨浅海相区。晚石炭世的岩相古地理与早石炭世相比，既有继承性，也有一定的差异，古陆范围有所小；有5个古陆，即阿勒泰古陆、北准噶尔古陆、马鬃山古陆、敦煌-阿拉善古陆、中天山古陆；有9个沉积相区，即库马苏河湖相区、布津-富蕴河湖相区、克拉美丽－巴里坤滨浅海相区、博乐－库尔勒－红柳园滨浅海相区、克拉玛依－哈密半深海－深海相区、乌鲁木齐生物滩丘区、柴达木碳酸盐岩台地相区、宗务隆山浅海-半深海相区、祁连滨浅海相区。半深海-深海相区、滨浅海相区和三角洲相区是较为有利的气分布区。     

A Nonlinear Model of Surf Beat

A nonlinear short-wave-averaged (surf beat) model is presented. The model is based on that of Roelvink (1993), but the numerical techniques used in the solution are based on the so-called weighted-averaged flux (WAF) method (eg Watson et al., 1992), with time-operator splitting used for the treatment of some of the source terms. This method allows a small number of computational points to be used, and is particularly efficient in modelling breaking long waves. The short-wave (or primary-wave) energy equation is solved using a more traditional Lax-Wendroff technique. Results of validation indicate that the model performs satisfactorily in most respects.     

共反射元弧叠加方法在火山岩成像中的应用

常规叠加方法假设叠加的地震道集的反射波来自地下同一个反射点,而地表观测到 的反射波场在空间上小于菲涅尔体范围是不可分辨的. 本文根据火山岩体特征,用元弧描述 火山岩的反射界面. 将来自菲涅尔体范围内的反射波沿着元弧界面求和,进而扩大叠加次数 ,达到增加反射信号能量提高地震反射波的叠加成像质量的目的. 文中给出了反射波走时参 数与地下元弧反射界面之间的联系和叠加实现的步骤. 计算结果表明,元弧叠加方法能够提 高剖面的信噪比,增加反射波同相轴的连续性.     

地球同步轨道附近哨声湍流对“种子电子”的加速

本文在等离子体准线性理论下研究了地球同步轨道附近哨声湍流对亚暴“种子电子”的波-电子共振相互作用. 当发生这种共振时，“种子电子”的动量分布函数经动量扩散而随时间演化，部分低能电子数减少了，而高能尾部分的相对论电子（能量大于1MeV）数增加了，说明“种子电子”得到了哨声湍流的有效加速，且哨声湍流的能量越高，其加速效率越高. 另外，哨声湍流的频率越低（或波数越小），共振电子的能量越高（或单位质量的动量越大）；频率范围越宽，共振电子的能量范围越宽，被加速的电子数也越多. 磁层哨声湍流加速“种子电子” 大约在30h内就可以造成相对论电子数显著增加，这正好和大多数磁暴期间观测到的相对论电子通量的增长时间相当.