A worldwide comparison of alkali olivine basalts and their differentiation trends     

Rudy R. Schwarzer  John J.W. Rogers 《Earth and Planetary Science Letters》1974,23(3):286-296

Worldwide alkali olivine basalts (AOB) and their differentiation series have been subdivided into continental, oceanic, or island-arc assemblages according to the inferred crustal environment at their time and place of eruption. No systematic differences have been found in major element composition of the AOB's from these three different environments. As plotted on (Na₂O + K₂O) vs. SiO₂ and AMF diagrams, AOB differentiation trends also show no differences between environments. Thus, AOB appears to be a primary magma generated at sufficient depth in the mantle that its major element content is unaffected by chemical or thermal differences between mantle regions underlying continents, ocean basins, or island arcs. The major element chemistry of AOB is also apparently unaffected by passage through different types of crust.  相似文献   

FREEWAT,a Free and Open Source,GIS‐Integrated,Hydrological Modeling Platform          下载免费PDF全文

Laura Foglia  Iacopo Borsi  Steffen Mehl  Giovanna De Filippis  Massimiliano Cannata  Enric Vasquez‐Suñe  Rotman Criollo  Rudy Rossetto 《Ground water》2018,56(4):521-523

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Fluid flow reconstruction in hanging and footwall carbonates: Compartmentalization by Cenozoic reverse faulting in the Northern Oman Mountains (UAE)     

Liesbeth Breesch  Rudy Swennen  Benoit Vincent 《Marine and Petroleum Geology》2009

In this paper, the diagenesis from either side of a major Cenozoic reverse fault in the Northern Oman Mountains is documented. Detailed petrographical and geochemical analysis of calcite-filled fractures in carbonate strata of Late Triassic and Early Cretaceous age in the hanging wall and footwall in Wadi Ghalilah reflect a different diagenetic history. In both hanging wall and footwall most of the fractures are pre-burial, extensional in origin, formed by a crack-seal mechanism, and the calcite vein infill has a host-rock buffered signature. In the hanging wall, the fluid responsible for calcite precipitation of these extensional fractures was a marine fluid at 60 °C. These veins predate deep burial and contractional tectonic deformation and consequently do not provide any information about syntectonic fluid flow. Neither do the pre-burial extension fractures in the footwall which are also host-rock buffered. The fractures post-dating the tectonic stylolitization in the footwall, by contrast, show evidence of syntectonic migration of saline formation waters at temperatures between 80 and 160 °C during contractional deformation. These fluids probably were sourced from the subsurface via the reverse fault, which acted as a fluid conduit. At the same time, however, this fault functioned as a permeability barrier towards the hanging wall, since no evidence of syntectonic fluid flow is present here. In this way compartmentalization of the hanging wall and footwall block was realized.  相似文献   

Gas-hydrate promotion by smectite–bioproduct interactions     

Jennifer L. Dearman  W. William Wilson  Rudy E. Rogers  Guochang Zhang 《Marine Chemistry》2009,115(1-2):21-30

Gas hydrates accumulate on the Gulf of Mexico seafloor around hydrocarbon seeps in waters sufficiently deep to provide adequate pressure/temperature combinations. High microbial activities occur around the hydrate accumulations. To understand apparent catalytic effects of bioproducts on hydrate formation, the mechanism of sII hydrate nucleation in unconsolidated porous media was investigated in our laboratory. Because smectite clays interacting with biopolymers had been shown to promote laboratory hydrates by decreasing induction times, increasing formation rates and altering morphology, these materials commonly found in near-surface sediments were selected for study as possible nucleating agents. Dynamic light scattering (DLS) with a helium–neon laser was used to measure particle diameters down to about 2 nm. Scanning electron microscopy (SEM) was utilized to verify particle sizes and to give additional information on biopolymer–clay associations. This paper presents evidence that nanometer-sized particles of mineral–bioproduct associations of about 80 nm–450 nm diameter may act as nucleation sites for hydrate crystal initiations in sediments and then remain dispersed throughout the accumulated hydrate mass. Emulsan biopolymer was shown by SEM to apparently unfold and associate with the smectite (nontronite) in a backbone arrangement and to give multiple hydrate nucleation sites along a linear network. SEM and DLS measurements were in agreement on particle sizes and shapes. X-ray diffraction suggested that biopolymer intercalates the smectite interlayer, probably driven by clay associations with biopolymer hydrophilic groups. It is hypothesized that hydrocarbon gases attach to biopolymer hydrophobic fatty-acid branches protruding from clay interlayers and subsequently facilitate hydrate structure formation by interacting with nearby water associated with the hydrophilic segments of the biopolymer.  相似文献   

A new approach to geobarometry by combining fluid inclusion and clumped isotope thermometry in hydrothermal carbonates          下载免费PDF全文

Robin Honlet  Marta Gasparrini  Philippe Muchez  Rudy Swennen  Cédric M. John 《地学学报》2018,30(3):199-206

This study presents a new approach to geobarometry by combining fluid inclusion and clumped isotope (Δ₄₇) thermometry on carbonate minerals. The offset between homogenisation temperatures of primary fluid inclusions with known composition and Δ₄₇ temperatures of the host mineral allows a direct estimation of the fluid pressure at the time of carbonate crystallisation. This new approach is illustrated via hydrothermal dolomite samples from the Variscan foreland fold‐and‐thrust belt in northern Spain. Clumped isotope analyses yield crystallisation temperatures (107–168°C) which are higher than homogenisation temperatures in corresponding samples (95–145°C). The calculated pressure values suggest that dolomitizing fluids were overpressured during formation of zebra dolomite textures, whereas lower pressures are obtained for dolomite cement from breccia textures. This new approach to geobarometry opens up the possibility of estimating the pressure of carbonate crystallisation and has potential applications in diagenesis, basin analysis, ore geology and tectonics.  相似文献   

Normal-branch quasi-periodic oscillations during the high-intensity state of Cygnus X-2     

Rudy Wijnands †  Michiel van der Klis 《Monthly notices of the Royal Astronomical Society》2001,321(3):537-543

Using data obtained with the Rossi X-ray Timing Explorer , we report the detection of a 5-Hz quasi-periodic oscillation (QPO) in the bright low-mass X-ray binary and Z source Cygnus X-2 during high overall intensities (the high-intensity state). This QPO was detected on the so-called normal-branch and can be identified with the normal-branch QPO or NBO. Our detection of the NBO is the first one during times when Cygnus X-2 was in the high-intensity state. The rms amplitude of this QPO decreased from 2.8 per cent between 2 and 3.1 keV to <1.9 per cent between 5.0 and 6.5 keV. Above 6.5 keV, its amplitude rapidly increased to ∼12 per cent rms above 16 keV. The time lags of the QPO were consistent with being zero below 5 keV (compared with the 2–3.1 keV band), but they rapidly increased to ∼70 ms (140°) around 10 keV, above which the time lags remained approximately constant near 70 ms. The photon energy dependences of the rms amplitude and the time lags are very similar to those observed for the NBO with other satellites ( Ginga , EXOSAT ) at different (i.e. lower) intensity states.  相似文献   

Insights from fluid inclusions, thermal and PVT modeling for paleo-burial and thermal reconstruction of the Córdoba petroleum system (NE Mexico)     

Helga Ferket  Nicole GuilhaumouFrançois Roure  Rudy Swennen 《Marine and Petroleum Geology》2011,28(4):936-958

Carbonate reservoirs in the Córdoba petroleum system (NE Mexico) passed through a multiphase deformation history complicating the petroleum geology. The area evolved from passive margin and foreland setting to Laramide fold and thrust belt (FTB) that was subsequently buried below the Tertiary-Quaternary Veracruz Basin, which in turn underwent transpressional deformation. Reconstruction of paleo-burial (erosion) and paleo-thermicity through the different zones of the FTB and adjacent foreland is a challenging task since classical calibration tools fail to discriminate between several kinematic and thermal models. In this study results from detailed diagenetic and fluid inclusion (FI) analyses on carbonates from the western part of the Córdoba Platform helped constraining paleo-thermicity. Combined microthermometry, synchrotron FTIR analyses and PVT modeling of cogenetic hydrocarbon-aqueous FI allowed also calculation of absolute pressures. Thermal modeling exercises calibrated with organic maturity parameters, bottom-hole temperatures or temperatures from FI demonstrate that without controlling also paleo-erosion the model results may be misleading.  相似文献   

XMM–Newton discovery of the X-ray transient XMMU J181227.8−181234 in the Galactic plane     

Edward M. Cackett  Rudy Wijnands  Ron Remillard 《Monthly notices of the Royal Astronomical Society》2006,369(4):1965-1971

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XMM–Newton observations of the black hole X-ray transient XTE J1650–500 in quiescence     

Jeroen Homan  Rudy Wijnands  Albert Kong  Jon M. Miller  Sabrina Rossi  Tomaso Belloni  Walter H. G. Lewin 《Monthly notices of the Royal Astronomical Society》2006,366(1):235-237

We report the result of an XMM–Newton observation of the black hole X-ray transient XTE J1650–500 in quiescence. The source was not detected, and we set upper limits on the 0.5–10 keV luminosity of  0.9–1.0 × 10³¹ erg s⁻¹  (for a newly derived distance of 2.6 kpc). These limits are in line with the quiescent luminosities of black hole X-ray binaries with similar orbital periods (∼7–8 h).  相似文献   

Determination of the cleat angle distribution of the RECOPOL coal seams, using CT-scans and image analysis on drilling cuttings and coal blocks   总被引：1，自引：1，他引：0  

Karl-Heinz A.A. Wolf  Frank van Bergen  Rudy Ephraim  Henk Pagnier 《International Journal of Coal Geology》2008,73(3-4):259-272

Cleat orientation, cleat frequency and cleat angle distribution of deep coal seams are only available by the use of drilling cores and from coal mine samples. Coal drilling cuttings are a cheap and fast alternative to measure cleat angle distributions with the use of image analysis techniques. In this study oriented coal samples and drilling cuttings of the RECOPOL field experiment are compared and used to explain and validate the proposed method. In other words, cleat angle distributions from drilling cuttings are measured by image analysis. The geological framework of the polish coals is described. The image analysis methodologies for the measurement of fracture faces of cuttings and from CT-scan images, derived from these coals, are explained. The results of the methods on the cuttings are compared with cleat orientation distributions from CT-scans and artificial fragments from coal blocks of the same seams. These evaluations show high agreements between the methods. The cleat angle distributions of drilling cuttings of four seams are compared with the cleat orientation distributions of a regional structural geological study. The high correlation in this study shows that cleat angle distributions of coal seams can be used as input parameters for reservoir modelling.  相似文献