Peculiarities of the deep structure of the lithosphere in the northeastern part of the Indian Ocean

The seismicity of the northeastern part of the Indian Ocean in connection with the general structural peculiarities of the main tectonic structures of the bottom is presented. The three main ranges of higher seismic activity at the depths of 0–17, 20–27, and 32–35 km divided by aseismic layers are revealed. The seismic activity at depths of more than 35 km is almost not detected both for the ocean and for the Indian peninsula. The nature of the distribution of the seismicity as such in the lithosphere is discussed. Using the results of anomalous au]gravitational field transformations, the prolongation of the East Indian Ridge structure is revealed to 19 degrees north, while the relationship of the Afanasy Nikitin Rise and the 85th Degree Ridge is not reflected at the tranforms. In the Cocos Basin, the mutually perpendicular disturbance zones of northeastern and northwestern strike, as well as the point of their crossing, where the maximal number of earthquake foci are concentrated, are distinguished. A conclusion concerning the substantial disturbance of the strength properties of the lithosphere in this zone as a consequence of the geodynamical processes, which are accompanied by fracture tectonics, is reached.     

Three-phase measurements of oil and gas trapping in sand packs

We measure the trapped saturations of oil and gas as a function of initial saturation in water-wet sand packs. We start with a water-saturated column and inject octane (oil), while water and oil are produced from the bottom. Once water production has ceased, air (gas) then enters from the top, allowing oil and gas to drain under gravity for different times. Finally water is then injected from the bottom to trap both oil and gas. The columns are sliced and the fluids analyzed using gas chromatography. We find that for high initial gas saturations more gas can be trapped in the presence of oil than in a two-phase (gas/water) system. The residual gas saturation can be over 20% compared to 14% in two-phase flow [Al Mansoori SK, Iglauer S, Pentland CH, Bijeljic B, Blunt MJ. Measurements of non-wetting phase trapping applied to carbon dioxide storage. Energy Procedia 2009;1(1):3173–80]. This is unlike previous measurements on consolidated media, where the trapped gas saturation is either similar or lower to that reached in an equivalent two-phase experiment. For lower initial gas saturation, the amount of trapping follows the initial-residual trend seen in two-phase experiments. The amount of oil trapped is insensitive to initial gas saturation or the amount of gas that is trapped, again in contrast to measurements on consolidated media. More oil is trapped than would be predicted from an equivalent two-phase (oil/water) system, although the trapped saturation is never larger than the maximum reached in two-phase flow (around 11%) [Pentland CH, Al Mansoori SK, Iglauer S, Bijeljic B, Blunt MJ. Measurement of non-wetting phase trapping in sand packs. In: SPE 115697, proceedings of the SPE annual technical conference and exhibition, Denver, Colorado, USA; 21–24 September 2008]. These initially surprising results are explained in the context of oil layer stability and the competition between snap-off and piston-like advance. In two-phase systems, displacement is principally by cooperative piston-like advance with relatively little trapping, whereas in consolidated media snap-off is generally more significant. However, oil layer collapse events during three-phase waterflooding rapidly trap the oil which acts as a barrier to direct water/gas displacement, except by snap-off, leading to enhanced gas trapping.     

Measurement of the influence of salinity on floc density and strength

The effective density and the strength of flocs formed in the laboratory from mud from the Tamar Estuary reached a maximum value at a salinity of 10–15‰ within the concentration range studied (0.1–1.0 g liter⁻¹). For a constant salinity and concentration, the density decreases with increasing floc size. The strength of the flocs increases with the floc diameter. However, the strength of the individual particle bonds within the floc decreases with size. Large flocs were relatively more brittle than smaller ones. The results suggest that larger flocs may be disrupted by the formation of unequal fragments.     

Aquifer Treatment of Sea Water to Remove Natural Organic Matter Before Desalination

An investigation of a sea water reverse osmosis desalination facility located in western Saudi Arabia has shown that aquifer treatment of the raw sea water provides a high degree of removal of natural organic matter (NOM) that causes membrane biofouling. The aquifer is a carbonate system that has a good hydraulic connection to the sea and 14 wells are used to induce sea water movement 400 to 450 m from the sea to the wells. During aquifer transport virtually all of the algae, over 90% of the bacteria, over 90% of the biopolymer fraction of NOM, and high percentages of the humic substance, building blocks, and some of the low molecular weight fractions of NOM are removed. Between 44 and over 90% of the transparent exopolymer particles (TEP) are removed with a corresponding significant reduction in concentration of the colloidal fraction of TEP. The removal rate for TEP appears to be greater in carbonate aquifers compared to siliciclastic systems. Although the production wells range in age from 4 months to 14 years, no significant difference in the degree of water treatment provided by the aquifer was found.     

Découverte de niveaux phosphatés associés à des restes de vertébrés dans les dépôts carbonatés du Coniacien–Santonien du Jabal Abtar : épisode précoce de la phosphatogenèse sénonienne des Palmyrides (Syrie centrale)

Sedimentologic study of carbonated sediments of the Rmah-I member (Coniacian–Santonian) of Jabal Abtar, central southern Palmyrides (Central Syria), uncovers phosphatic levels, associated with marine vertebrate remains, that give evidence of an early episode of the Senonian phosphatogenesis in the Palmyrides. Sedimentary sequence analysis reveals a gradual marine transgression during the Senonian. Phosphatic sedimentation occurred in a shallow neritic marine environment almost connected with the open sea. Condensed sedimentation could have contributed to the phosphatogenesis. To cite this article: A.K. Al Maleh, N. Bardet, C. R. Geoscience 335 (2003).     

Ionized gas in the circumgalactic vicinity of the M81 galaxy group

The dynamics of the dust and gas in the tidal region of the M81 galaxy group have been analyzed, and the drift of the dust relative to the gas has been estimated, including the drift due to the action of radiation pressure from stars in M81. It is concluded that a large fraction of the gas in the tidal region is in the form of ionized hydrogen HII that shields the observedHI gas from the extragalactic Lyman continuum: the observed atomic gas could be only 10% of the total mass of gas. Only then it is possible to satisfactorily explain the excess dust abundance, which exceeds the Galactic value by a factor of six. By analogy, extended HI disks in galaxies with sizes appreciably larger than the stellar disks could be surrounded by HII envelopes with a comparable or greater mass. Such disks could play an important role in supporting prolonged star formation in galaxies with extended HI disks. Associated observational manifestations are discussed. Such HII envelopes outside HI disks could be detectable in absorption in Ly α and lines of ions of heavy elements.     

Engineering Geological Properties of Building Stones from the North-Eastern Part of the Vienna Basin in the Western Carpathians

Geotechnical and Geological Engineering - This research focuses on assessing the most important physical and mechanical properties of rocks that were quarried from the north-eastern part of the...     

Assessment of extraction drainage pattern from topographic maps based on photogrammetry

The extraction of the water hydrographical pattern and watershed and subwatershed boundary is very important for many types of study. In Jordan the topographic map scale 1:25,000 produced at the Royal Jordanian Geographic Center is considered the most important source of contour lines and drainage pattern; therefore, it is imperative to estimate the accuracy of these types of data extracted from the previous topographic maps. In this project we aim to extract the hydrographical pattern of the Humrat Assahn basin in two methods: (1) an orthophoto based on aerial photographs using Socetset as photogrammetric software and (2) topographic maps at scale 1:25,000. A precise Digital Terrain Model (DTM) was built from stereoscopic aerial photographs using Socetset software. As we know, the quality of DTM is imperative to assure precise results and depends on the method of creation of this DTM besides other factors. A complete data base for the necessary information for achieving this objective was built. The obtained results were evaluated using GPS points and photo-interpretation. The results show that the drainage pattern extracted from DTM using photogrametric software was very accurate; meanwhile, the accuracy of the drainage pattern extracted from topographic maps has some flaws.     

Isoprenoid alkanes with irregular “head-to-head” linkages

A lightly biodegraded crude oil from the Tolkinsk field (Upper Jurassic), situated in north-west Siberia, was found to contain a series of C₂₈–C₃₉ isoprenoid alkanes. Most of these components contain a pristane unit linked head-to-head with other isoprenoid units. The structures of these components were elucidated by mass spectral interpretations, comparisons with a synthesised standard and by reference to data published previously in the literature. These results extend the carbon number range, the variety of structural types, and the number of reported occurrences of these compounds in geological samples. These results provide further evidence for a contribution of bacterial cell-wall lipids to crude oils.