Aerodynamic roughness length of sandy beds and gravel beds

A physical model was developed for the aerodynamic roughness length of gravel beds and sandy beds under different atmospheric stability conditions based on Monin?CObukhov similarity theory and dimensional analysis. The relationship between the roughness length, the properties of the roughness elements, the characteristics of the airflow, and an atmospheric stability parameter (the bulk Richardson number) was then studied using the model. Results showed that the roughness length was not only functions of the shape, height, and coverage of the roughness elements and of the airflow, but also dependent upon atmospheric stability. These results were in agreement with results from wind tunnel experiments and field observations.     

CPT data in normally consolidated soils

The paper presents observations made in CPTs performed under controlled laboratory conditions in normally consolidated clay–sand mixtures at various penetrations. These results are combined with data from field tests to develop a relationship for CPT data in young normally consolidated soils that combines end resistance and friction sleeve data. This relationship can be used to assist assessment of soil type and CPT parameters for un-aged normally consolidated soils as well as allowing judgements to be made in relation to likely levels of under-consolidation, structure and over-consolidation in any given soil deposit.

     

分水岭算法在电成像测井图砾石识别中的最优参数研究

基于电成像测井,将分水岭算法应用到电成像测井图砾石的识别中,分水岭算法在砾石识别应用中的参数选取直接影响到识别效果。针对分水岭算法识别砾石的各个步骤,选取不同的优化参数进行处理,对处理效果进行对比分析,最终确定分水岭算法识别砾石的最优参数,并对吉林王府断陷AA井、BB井和CC井三口井进行实际处理,得到很好的效果。     

喀斯特小流域土壤石砾分布特征及其影响因素

为探究喀斯特土壤石砾含量的影响因素、形成机制及其分布规律,采集了3 180个土壤样品,分析后寨河流域不同影响因素下土壤石砾含量的分布规律,并利用相关性分析得出了影响后寨河流域土壤石砾含量的主要影响因子。结果表明,坡度、岩性、土层厚度和植被类型是影响土壤石砾含量分布的主要影响因素,其中坡度对喀斯特地区土壤石砾含量的分布特征影响作用最大。在不同坡度条件下,土壤石砾含量的分布规律为:坡度<30°时随坡度增加,土壤石砾含量增大。坡度>30°时随坡度增加,土壤石砾含量减小。不同土层厚度下,土壤石砾含量分布规律为:随土层厚度增加,土壤中石砾含量减少。植被类型不同,土壤石砾含量大小排序为:灌木>草本>乔木。不同岩性发育形成土壤,土壤石砾含量大小排序为:白云岩>石灰岩>泥灰岩>第四纪黄粘土>砂页岩。喀斯特地区岩性决定风化成土速率和土壤石砾总量,是土壤石砾含量的物质来源基础。坡度是促进土壤石砾含量迁移、再分配的驱动因素,植被类型和土层厚度是影响土壤石砾含量的响应因素。      

阳原县泥河湾地层中的新发现

河北省阳原盆地位于冀西北,盆地内发育著名的第四系泥河湾层,桑干河自西向东贯穿盆地之中,滋养哺育了史前文明,这里是我国重要的层型剖面保护区之一。1997年,我们在完成1：50000阳原幅和井儿沟幅区调填图项目‘)时,在泥河湾层中、上部及山前冲一洪积中又有新的发现。l火山尘凝灰岩阳原盆地之西毗邻大同火山岩群,长期以来不少地质学家想在泥河湾河一湖相层中寻找火山物质,但一直未能如愿。我们这次在井儿沟幅开阳水库附近找到一层灰白色粉砂质泥岩层,经分析,火山物质粒级为0．005～0．05mm,属火山尘。X射线衍射分析内含白云岩、石英、长石、高岭石(少量)和伊利石一蒙脱石混层,据成分和结构特点及火山物质含量＞     

红层砾石组分是区域地层对比的良好标志──以赣西北中─晚第三纪的砂砾岩为例

根据赣西北中─晚第三纪陆相紫红色砂砾岩岩性横向上不太稳定的特点，提出砾石成分的来源和成因特征可作为区域地层对比的标志，因为砾石成分作为风化和搬运的最终产物，它与基底母岩区是密不可分，又相互影响。     

New data on the structure of the Sea of Okhotsk bottom

The reinterpretation of the time and deep sections along CDP Profile 1632 revealed different previously unknown structural features: (1) a buried bar and a Late Pliocene regional unconformity, the Bol’sheretsk and Lebed subaerial shield volcanoes, and the Koni-P’yagina and Magadan megadikes at its level; (2) morphological evidence for the nappe structure of the Okhotsk Arch (homoclinal thrust slices of the acoustic basement with ramp half-grabens in the frontal part and a pull-apart zone with a solitary diapir in the Kol’skii Trough, which divides the arch into two allochthonous megablocks with opposite vergence of their thrusts), which is related to a divergent sheet decollement, probably, at the M discontinuity.     

Effect of open-framework gravel on suffusion in sandy gravel alluvium

Acta Geotechnica - Some accidents of dams are attributed to suffusion around open-framework gravel (OFG) in sandy gravel alluvium. However, whether OFG can be really an internal seepage exit of...     

New data on the geological structure of the gas Aral-Kyzylkum shaft

Shaft-like structures that host petroleum deposits were studied within the Epi-Paleozoic plates using seismic methods. This study is very topical, as it revises existing ideas on the geological structure and tectonic position of the Aral-Kyzylkum shaft and presents the author’s 3D model of this structure, which was constructed on the basis of interpretation of 2D seismic data. It was established that tectonic uplift of the Aral-Kyzylkum shaft is an Alpine positive structure, which was initiated above the Early Cimmerian system of grabens in the modern strain field. This revision allowed us to propose a new model of petroleum structures of this type and estimate the possibility of using structural-geological approaches to an analysis of their petroleum potential.     

Using magnetic resonance imaging for experimental analysis of fine‐sediment infiltration into gravel beds

Sedimentologists recognize that development of a fine‐resolution, truly three‐dimensional analytical tool is essential if the internal structure of an opaque material is to be examined. This paper therefore seeks to: (i) test the viability of magnetic resonance imaging for sedimentological research; and (ii) investigate fine‐sediment infiltration into gravel beds. The results of six experiments are analysed quantitatively using Image J post‐processing software. Data indicate that magnetic resonance imaging‐based measurements of particle axes and volumes are comparable with standard laboratory techniques. Furthermore, the technique permits visualization and analysis of differences in the pattern of fine‐sediment infiltration (median particle diameter, d) into a framework of gravel (median particle diameter, D). Data clearly illustrate a siltation process for samples of D/d = 34 and a sealing process for samples of D/d = 7 where the seal is restricted to a depth equal to 2D. This pore‐scale visualization is valuable to the understanding of hydraulic–sediment–habitat interactions.     

New data on the structure of the Knipovich Ridge,North Atlantic

The Knipovich Ridge extends for 550–600 km between the Mohns Ridge and the demarcation Spitsbergen Fracture Zone. The structural features of this ridge are repeatedly mentioned in the literature; however, substantial discrepancies remain in the treatment of its tectonics. New data on the structure of this ridge presented in this paper are based on the results of continuous seismic profiling in the area studied by the expedition of the Geological Institute, Russian Academy of Sciences and the Norwegian Petroleum Directorate on the R/V Akademik Nikolaj Strakhov in 2006; 56 seismic lines allow us to depict zones differing in seismic records that provide insights into their internal tectonic structure. Interpretation of the seismic data makes it possible to compile maps of the acoustic basement surface and sedimentary cover thickness in the studied area. These maps expand our knowledge of the geological history and geodynamics of the Knipovich Ridge at the neotectonic stage of its evolution.     

清江流域水库滑坡数据库系统开发

介绍了清江流域水库滑坡数据库系统的数据结构、功能及窗口界面等特点。本系统利用VFP的可视化和面向对象的编程技术，实现了数据库系统强大的数据查询、数据维护、报表打印及系统维护管理功能，并具有与WINDOWS系统完全一致的窗口界面。     

New data on the deep structure of the South Kochkor zone of concentrated deformation

Based on a complex study of the upper crust structure in the southern margin of Kochkor basin (Northern Tien Shan), including study of the structure of the Cenozoic sedimentary cover, the deep geoelectrical structure, the structural unconformities, and occurrences of recent deformations in the basement rocks, new geological–geophysical cross sections are constructed. The cross sections show both fault structures that penetrate the cover from the basement and flat interplate detachments with related fold-overthrust structures. The comparison of the cross sections has established the absence of common planes of fault extensions along the entire margin of the hollow, except for the zone where the margin and the hollow adjoin, which can be caused by the zones of dynamic influence of secondary faults, the zones of fracturing, and the zones of cataclasis of blockwise disintegrated granite massifs.     

New data on deep structure, tectonics, and mineralogeny of the Zeya-Bureya Basin

The Zeya-Bureya Basin is a part of the East Asian intracontinental riftogenic belt, which includes oil-and-gas bearing and Mesozoic-Cenozoic sedimentary basins perspective for oil and gas (Upper Zeya, Songliao, Liaohe, North Chinese). The basins are characterized by certain geophysical features: reduced thickness of the Earth’s crust and lithosphere, a higher thermal flow and a raised roof of the asthenosphere. The Zeya-Bureya Basin is composed of Mesozoic-Cenozoic sedimentary-volcanic units, with respect to which the deep structure data are absent. In 2010, geoelectric studies were carried out in this territory using the method of magnetotelluric sounding along the profile Blagoveshchensk-Birokan. These works yielded geoelectric sections down to 2 and 200 km depth. The sedimentary cover is characterized by electric resistivity of 20–50 Ohm m and by thickness of 1700 m. In the section, the Khingan-Olonoi volcanogenic trough is distinct for resistivity of 200–300 Ohm m at a background of 500–1000 Ohm m of the basement rocks. The Zeya-Bureya Basin, in terms of its geophysical characteristics, differs from oil-and-gas bearing basins of the riftogenic belt (thickness of the lithosphere is increased up to 120 km, thermal flow is low, 40–47 mW/m²). The structure of mantle underplating is explicitly seen in the section. The geophysical characteristics close to those of the Zeya-Bureya Depression are typical for gold-bearing structures of the Lower Amur ore district. Nevertheless, manifestations of oil-and-gas bearing potential in particular grabens are possible.     

New data on the geological structure of the southwestern Mendeleev Rise,Arctic Ocean

This communication considers the ideas about the geological structure of the southwestern Mendeleev Rise belonging to the East Arctic rises of the Arctic Ocean. These ideas have resulted from analyzing the data obtained from bathymetric surveys, visual observations, and bottom coring using the technical tools of a research submarine. We distinguished the lower sequence of quartzite sandstones and dolomites, which has a visible thickness of about 230 m and occurs in the lowermost visible section, at depths between 1500 and 1270 m. This sequence is superimposed with stratigraphic and angular unconformity by the upper sequence of limestones and sandstones having a visible thickness of 40 m. The lower sequence is pierced by subvolcanic rocks of basaltic to andesitic composition, and in the lowermost part of the slope, a tuffaceous sequence having a visible thickness of 50 m adjoins it.     

利用钻孔资料预测矿井未采区煤层瓦斯含量

利用矿井采掘区煤层瓦斯含量实测值,在瓦斯地质定性分析基础上,通过丰富翔实的钻孔资料建立井田未采区适用的煤层瓦斯含量预测公式,从而达到对井田煤层瓦斯含量预测的目的。为大型低瓦斯矿井煤层瓦斯含量预测提供了思路和方法。