The effect of a submarine canyon on the river sediment dispersal and inner shelf sediment movements in southern Taiwan

This study examines the influence of a submarine canyon on the dispersal of sediments discharged by a nearby river and on the sediment movement on the inner shelf. The study area includes the head region of the Kao-ping Submarine Canyon whose landward terminus is located approximately 1 km seaward from the mouth of the Kao-ping River in southern Taiwan. Within the study area 143 surficial sediment samples were taken from the seafloor. Six hydrographic surveys along the axis of the submarine canyon were also conducted over the span of 1 yr. Three different approaches were used in the analysis of grain-size distribution pattern. They include (1) a combination of ‘filtering’ and the empirical orthogonal (eigen) function (EOF) analysis technique, (2) the McLaren Model, and (3) the ‘transport vector’ technique. The results of the three methods not only agree with one another, they also complement one another. This study reveals that the Kao-ping Submarine Canyon is relatively a stratified and statically stable environment. The hydrographic characteristics of the canyon display seasonal variability controlled primarily by the temperature field and the effluent of the Kao-ping River. The hydrographic condition and the bottom topography in the canyon suggest the propagation of internal tides during the flood season (summer) of the Kao-ping River. The submarine canyon acts as a trap and conduit for mud exchange between the Kao-ping River and offshore. Near the head of the canyon there is a region of sediment transport convergence. This region is also characterized by high mud abundance on the seafloor that coincides with the presence of high suspended sediment concentration (SSC) spots in the bottom nepheloid layer. Outside the submarine canyon on the shelf where the evidence of wave reworking is strong, the northwestward alongshore transport dominates over the southeastward transport, which is a common theme on the west coast in southern Taiwan.     

MODELLING THE LONG-TERM COURSE OF NON-FLUSHED RESERVOIR SEDIMENTATION AND ESTIMATING THE LIFE OF DAMS

An analysis of hydrologic and geodetic data from numerous reservoirs lying in different climatic zones, has allowed the two main phases in filling the reservoir during its life to be distinguished, firstly silting of an originally deep reservoir, and secondly silting of a reservoir which has become shallow or initially was not deep. During the first phase, the reservoir plays a role as an accumulator of sediment, so that its trap efficiency for total mineral material is much reduced, and its trap efficiency for suspended load decreases to zero. This phase ends when the mean depth reaches a critical value which is specific for each reservoir. During the second phase, shallowing of the reservoir is much slower, and over short time periods it can play a role as a net exporter of sediment. A general model of reservoir sedimentation is proposed and is tested by data on the long-term and seasonal courses of siltation in selected reservoirs in the Vistula drainage basin, Poland. The rate of sedimentation is analysed for both phases of siltation, and the useful lifetime of a reservoir, which corresponds to the first phase of siltation, has been computed according to a methodology proposed.     

博格斯盆地深水挤压盐构造识别与圈闭落实关键技术及应用

墨西哥湾油气资源非常丰富,与盐岩形变相关的圈闭的落实是该区勘探的主要难题,亟待形成一套有效的盐构造识别与圈闭落实技术。以墨西哥博格斯盆地深水区为研究靶区,利用地震、钻井和重力资料,从盐岩的岩石物理性质出发,根据浅层异地盐岩、深层原地盐岩岩、盐岩流动通道和围岩的地震反射特征,总结形成了一套以双层盐岩构造识别为核心的圈闭落实关键技术组合,主要包括：双层盐岩构造雕刻与分析技术、基于地震-物模的多信息断裂解释技术、基于标志层约束的全三维层位解释技术、基于处理解释一体化的盐模型判别技术。应用该项技术组合,完成了研究区多个重点目标的精细落实,其中A圈闭钻探证实构造落实可靠。形成的技术体系也可为其他含盐盆地的盐相关构造解释和分析提供参考。     

溱潼凹陷边城-叶甸地区构造解释及储层预测

通过使用Landmark软件包的合成地震记录、相干技术对溱潼凹陷边城—叶甸地区地震资料进行精细构造解释，应用Gridstatpro油藏描述技术对储层进行预测。分析了该区虽多口钻井油气显示活跃，但并未发现工业油流的原因，在此基础上，进一步落实了局部构造，优选出可供上钻的有利圈闭3个。     

Grain size,La/Yb and Th/Sc of settling particles in the western North Pacific: Evidence for lateral transport of small Asian loess

To understand the transport process of lithogenic particles in the ocean, we measured the grain size distributions of lithogenic particles and measured the opal, La, Yb, Th, and Sc concentrations of the settling particles collected from time-series sediment traps at Sta. KNOT (44°N, 155°E, water depth 5320 m) from June 2002 to May 2004. The annual mean lithogenic particle flux observed at the lower sediment trap (5100 m) was twice as high as that at the upper sediment trap (770 m). The contribution of Asian loess estimated by the La/Yb and the Th/Sc ratios in the lower layer was greater than that in the upper layer. The fluxes of small lithogenic particles with sizes of 3–4 μm at the lower layer (5 to 65 mg/m²/day) were approximately four times larger than that at the upper layer (0.6 to 27 mg/m²/day). These results indicate that the horizontal addition of small particle sizes of Asian loess is a main factor in the increase of lithogenic particles at the lower layer. The temporal variations in the small lithogenic particle flux at the lower layer had a positive correlation with those at the upper layer (r = 0.71). The small lithogenic particle fluxes showed a strong positive correlation with the opal fluxes (r = 0.9). We therefore conclude that the small lithogenic particles were laterally transported and scavenged by the formation of aggregates with opal.     

伊朗卡山探区Aran背斜圈闭的地球物理综合评价

针对伊朗卡山探区勘探程度低、周期短、难度大、风险高的特点，通过地球物理资料，特别是地震资料的处理和解释，结合探区外围的地质调查和油气田资料，进行了油气藏圈闭可靠性、储集封堵条件、有效性及含油气性等方面的地球物理资料预测，探索出了一套早期勘探区域圈闭评价的新方法。利用该方法对该探区的Aran背斜圈闭进行了综合评价，取得了良好的效果。     

赤道印度洋中部沉降颗粒物的季节变化特征及调控机制研究

基于2020年1—12月在赤道印度洋中部海域获取的沉积物捕获器时间序列样品,分析了沉降颗粒物与颗粒有机碳（particulate organic carbon, POC）通量的季节变化特征,并结合卫星遥感、数值模式及再分析数据探究上层物理过程对生物泵输出通量的调控作用。结果表明,2020年赤道印度洋中部海域的沉降颗粒物总通量与颗粒有机碳通量的变化范围分别为4.57~35.75 mg/(m2·d)\[(18.94±10.18) mg/(m2·d)\]和0.27~2.97 mg/(m2·d)\[(1.09±0.66) mg/(m2·d)\],两者均呈现显著的季节变化特征。总体上,1—3月、6月和9—11月呈现出3个显著的高通量事件。通过分析发现混合层深度变化与营养盐跃层波动的耦合作用可能是调控中深层通量变化的主要原因。与此同时,西南季风流（Southwest Monsoon Current, SMC）与赤道Wyrtki急流生消也可能通过改变温跃层或营养盐跃层深度对沉降颗粒物通量强度和季节变化起调控作用。     

油气圈闭定量化地质评价

在定量化地质方法评价圈闭含油气性的过程中,首先用区域地质资料、钻井资料、地震资料等建立这个地区的数值模板,其次就是把要评价的圈闭地质条件和这个模板作比较。然后给这些圈闭评分。最后用数学方法对这些评分进行计算。其计算结果就表示圈闭评价结果,数值越高,评价效果也越高。     

海洋激流的观测实验及分析讨论

海洋中存在着冲击力极强的海洋激流,这已是不争的事实.从20世纪70年代起,一些国家就开始对大洋海底激流进行现场观测.据报道,他们所观测到的异常的底层流速的最大值仅为0.4m/s,却被视之为海底激流加以分析研究[1～5].     

北部湾盆地涠西南凹陷油气成藏条件分析

涠西南凹陷位于北部湾盆地西南部,发育有多个油气田(含油气构造)。以油气地质理论为指导,在构造和沉积地层特征研究的基础上,重点分析了烃源岩、储集层、圈闭及输导介质等油气成藏的基本要素,认为涠西南凹陷拥有较好的烃源岩、发育多套储集层、多种类型圈闭和复合的输导介质,具备油气藏形成的基本条件,具有广阔的油气勘探前景。