鄂尔多斯盆地奥陶系马家沟组五段上部沉积成岩特征与天然气聚集

本文将沉积、成岩和储集性三者结合起来研究，建立了泥云坪压实沉积成岩相区、含膏云坪岩溶孔洞沉积成岩相区，膏泥云坪浅凹压 实交代充填沉积成岩相区等 三种沉积成岩类型，分析了各相区的沉积构造特征，成岩特征，储集性能，指出了含膏云坪岩溶孔沉和只成岩相带是天然气富集的最有利储集相带。     

Tidal Flat Morphodynamic Processes of the Yangtze Estuary and Their Engineering Implications

—The intertidal flats are classified as"attached bar"."spit"and"isolated bar"in relation to theland.and"broad flat","sharp bank"and"eroded cliff"according to the shape of the cross-shore profile.Tidal currents on the flat are basically back and forth along the river channel banks but gyratory on theseaward side of the Chongming Island.The flow velocity on the intertidal flat is gradually reduced with in-creasing elevation.The river discharge strengthens ebb flows and modifies current asymmetry especiallyon the lower flat in neap tide.although hydrodynamics over the tidal flat is tide-dominated.The waveheight on the tidal flat is normally limited to a few decimeters although it changes with water depth.slopeand wind.Suspended sediment concentration over the tidal flat is typically hundreds to thousands ofmg/l.Although the delta has grown rapidly in history.the rate of growth is different in different periods.A maximum advancing rate of 330m/a was recently found in the central part of the river mouth towa     

From oblique subduction to intra-continental transpression: Structures of the southern Kermadec-Hikurangi margin from multibeam bathymetry,side-scan sonar and seismic reflection

The southern Kermadec-Hikurangi convergent margin, east of New Zealand, accommodates the oblique subduction of the oceanic Hikurangi Plateau at rates of 4–5 cm/yr. Swath bathymetry and sidescan data, together with seismic reflection and geopotential data obtained during the GEODYNZ-SUD cruise, showed major changes in tectonic style along the margin. The changes reflect the size and abundance of seamounts on the subducting plateau, the presence and thickness of trench-fill turbidites, and the change to increasing obliquity and intracontinental transpression towards the south. In this paper, we provide evidence that faulting with a significant strike-slip component is widespread along the entire 1000 km margin. Subduction of the northeastern scrap of the Hikurangi Plateau is marked by an offset in the Kermadec Trench and adjacent margin, and by a major NW-trending tear fault in the scarp. To the south, the southern Kermadec Trench is devoid of turbidite fill and the adjacent margin is characterized by an up to 1200 m high scarp that locally separates apparent clockwise rotated blocks on the upper slope from strike-slip faults and mass wasting on the lower slope. The northern Hikurangi Trough has at least 1 km of trench-fill but its adjacent margin is characterized by tectonic erosion. The toe of the margin is indented by 10–25 km for more than 200 km, and this is inferred to be the result of repeated impacts of the large seamounts that are abundant on the northern Hikurangi Plateau. The two most recent impacts have left major indentations in the margin. The central Hikurangi margin is characterized by development of a wide accretionary wedge on the lower slope, and by transpression of presubduction passive margin sediments on the upper slope. Shortening across the wedge together with a component of strike-slip motion on the upper slope supports an interpretation of some strain partitioning. The southern Hikurangi margin is a narrow, mainly compressive belt along a very oblique, apparently locked subduction zone.     

河口潮滩沉积物磷的季节性累积和生物有效性

对长江口潮滩表层沉积生磷的赋存形态和含量的研究表明,碎屑态磷为沉积物中磷的主要形态,约占总磷的62.52%;铁结合态磷和有机磷次之,分别占总磷的18.06%和14.69%;自生磷灰石加钙结合态磷和吸附态磷最少。综合研究区内的各种理化条件,指出弱吸附态磷、铁结合态磷和有机磷是长江口潮滩潜在生物可利用磷,约占总磷的33.16%,是导致水体富营养化的潜在因素。上覆水的盐度效应是影响沉积物铁结合态磷含量的关键性因子;而自生磷灰石加钙结合态磷的含量变化则与上覆水的温度、溶氧量及沉积物有机质的分解有关;有机磷在时间和空间尺度上都存在较大变化,主要与潮滩生物动态过程,即磷的再矿化有关。     

乐清湾潮汐特征及对潮滩沉积作用的影响

本文通过对乐清湾潮汐特征的研究,结合流路的模拟结果,阐述了湾内泥沙输运的途径,从而说明了潮动力对湾内潮滩沉积作用的影响。     

Application of a two-way nested model to the seamount problem

A two-way nested model has been constructed and applied to the idealized ocean where a uniform mean flow impinges on the isolated Gaussian-shaped seamount and produces two eddies (cold and warm) in the depths. The performance of the nested model has been evaluated subjectively and objectively. Both subjective and objective analyses confirm the traditional view that the nested model can well capture the performance of isolated eddies. Objective analysis, however, reveals some quantitatively important features of a two-way nested model. One is penetration of improved features into the coarse domain and another is the deterioration of mean flow field inside the nested area, neither of which is clear from subjective analysis. With successful application of two-way nested model to the seamount problem, we expect that such a nested model will also be applicable to other oceanic phenomena, particularly to some coastal problems whose time scale is short and where the topographic effects are dominant.     

Chemical Associations of Heavy Metals in the Sediments near Bailonggang Sewage Discharge Outlet of Shanghai

The five chemical associations ofheavy metals have been extracted continuously using the Tessier extracting method.Results show that Cu,Pb,Fe,Zn and Cr in the sediments are mainly distributed in residual fraction,while the major chemical association of Mn is carbonates.Carbonate heavy metals are converted into Fe-Mn oxides in autunm.And in the low tidal flat,after carbonates have changed into ionic heavy metals,some of the elements are transported to the overlying water,Cu,Pb,Fe and Mn have good correlations with each other,and Zn,Cr also show their similarity of chemical behavior in the sediments.     

Wave Attenuation and Friction Coefficient on the Coral-Reef Flat

Several sets of S4 direction-wave-current-tide meters have been deployed on the coral-reef fiat of Yongshu Reef in the sea area of Nansha Islands. Based on the observational sea wave data, the attenuation characteristics of the waves propagating on the coral reef flat, the bottom friction coefficients and the transfer of wave energy are discussed in the paper. The results show that, in the relative depths of 0. 0613- 0.0867, the wave height attenuation per unit distance of wave propagation is 22.09 %-46.56%, with an average of 31.35 % ; the wave energy, attenuation coefficient, 33.74 %- 53.22%, with an average of 43.61%. The average of the bettom friction coefficients on the coral-reef flat is 0. 1346,which is about 10 times thai on the sand or silt bottom. In the couse of propagation on the reef flat, the waves sustain more loss in high frequency than in low frequency and the spectral energy transfers to the low frequency. These results may be used for reference in island and reef engineering.     

沿海滩涂开发强度与维持平衡的临界阈值探讨

在分析浙江省滩涂动态平衡实测资料的基础上,建立了沿海滩涂演变动态预测的数值模型,经飞云江河口丁山围涂工程等实测资料验证表明,该模型基本上反映了滩涂动态演变特性.在此基础上利用实测资料和滩涂动态预测数值模型计算出滩涂开发强度与动态平衡的临界阈值,探讨了维持滩涂动态平衡的对策与措施.指出滩涂开发利用与社会经济协调发展的关键是保持滩涂的动态平衡.