The Preparation and Preliminary Characterisation of Eight Geological MPI-DING Reference Glasses for In-Situ Microanalysis   总被引：13，自引：4，他引：9  

Klaus Peter Jochum  Donald B. Dingwell  Alexander Rocholl  Brigitte Stoll  Albrecht W. Hofmann  S. Becker  A. Besmehn  D. Bessette  H.-J. Dietze  P. Dulski  J. Erzinger  E. Hellebrand  P. Hoppe  I. Horn  K. Janssens  G.A. Jenner  M. Klein  W.F. McDonough  M. Maetz  K. Mezger  C. Müker  I.K. Nikogosian  C. Pickhardt  I. Raczek  D. Rhede  H.M. Seufert  S.G. Simakin  A.V. Sobolev  B. Spettel  S. Straub  L. Vincze  A. Wallianos  G. Weckwerth  S. Weyer  D. Wolf  M. Zimmer 《Geostandards and Geoanalytical Research》2000,24(1):87-133

Eight silicate glasses were prepared by directly fusing and stirring 50-100 g each of basalt, andesite, komatiite, peridotite, rhyolite, and quartz-diorite. These are referred to as MPI-DING glasses and were made for the purpose of providing reference materials for geochemical, in-situ microanalytical work. Results from various analytical techniques indicate that individual glass fragments are well homogenised with respect to major and trace elements at the μm to mm scale. Heterogeneities due to quench crystallisation of olivine have been observed in small and limited areas of the two komatiitic glasses. In order to obtain concentration values for as many elements as possible, the glasses were analysed by a variety of bulk and microanalytical methods in a number of laboratories. The analytical uncertainties of most elements are estimated to be between 1% and 10%. From the analytical data, preliminary reference values for more than sixty elements were calculated. The analytical uncertainties of most elements are estimated to be between 1% and 10%.  相似文献   

Non-Fickian mixing: Temporal evolution of the scalar dissipation rate in heterogeneous porous media     

Tanguy Le Borgne  Marco Dentz  Diogo Bolster  Jesus Carrera  Jean-Raynald de Dreuzy  Philippe Davy 《Advances in water resources》2010

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Discrete clay diagenesis in a very low-permeable sequence constrained by an isotopic (K–Ar and Rb–Sr) study     

Davy?Rousset  Norbert?ClauerEmail author 《Contributions to Mineralogy and Petrology》2003,145(2):182-198

Multimethod analyses of several size fractions of clays were used to reconstruct the diagenetic history of the shallow buried claystones within the Paris Basin. A systematic decrease occurred in K-Ar dates relative to the decrease in size of the clay fractions, signifying higher amounts of newly formed clay material in the finer fractions. We suggest that the authigenic clay minerals occurring in the fine fractions had an Al-montmorillonite composition. By assuming that the isotopic K-Ar and Rb-Sr dates obtained on a bentonite layer in the sedimentary sequence stand for pure, authigenic clay minerals, one may interpret all K-Ar dates as mixtures of one authigenic and two detrital end-members. The results imply that a period of low sea level favoured diagenetic smectite-type clay formation about 10-15 million years after deposition of the sediments. Signatures of limited-scale chemical and isotopic homogenisation mean that the rock volumes affected by the diagenetic modifications had to be quite limited. The study of clay minerals extracted from some stylolites further suggests that any overpressure related to the origin of stylolites had no effect on clay authigenesis.  相似文献   

An example of radio and optical homologous flares     

K. P. White III  T. J. Janssens 《Solar physics》1970,11(2):291-298

Fokker (1967) has raised the question of whether the optical and radio homologies of flares are correlated. Two 2b flares occurring nearly 54 h apart (July 9 and 12, 1968) were observed at 29 wavelengths from H+4.00 Å to H–4.26 Å and at 10-cm radio. Adjacent pictures were spaced 0.295 Å and 2 sec apart. The time resolution of the radio traces was about 10 sec. Detailed comparison of the pictures showed near-perfect similarities in the two events. These similarities included flare shape, filament agitation, rising arch formation and surges with line-of-sight velocities nearly 200 km/ sec observed. Comparion of the microwave radio flux traces showed detailed similarities in the shapes and simultaneity of at least eight features.Research supported in part by the Atmospheric Sciences Section, National Science Foundation, NSF Grant GA-4184, while at Harvey Mudd College, Claremont, Calif.  相似文献   

Thickening history of the Western Alps     

Ph. Gillet  P. Choukroune  M. Ballvre  Ph. Davy 《Earth and Planetary Science Letters》1986,78(1)

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A precipiton‐based approach to model hydro‐sedimentary hazards induced by large sediment supplies in alluvial fans          下载免费PDF全文

Thomas Croissant  Dimitri Lague  Philippe Davy  Tim Davies  Philippe Steer 《地球表面变化过程与地形》2017,42(13):2054-2067

Mountain ranges are frequently subjected to mass wasting events triggered by storms or earthquakes and supply large volumes of sediment into river networks. Besides altering river dynamics, large sediment deliveries to alluvial fans are known to cause hydro‐sedimentary hazards such as flooding and river avulsion. Here we explore how the sediment supply history affects hydro‐sedimentary river and fan hazards, and how well can it be predicted given the uncertainties on boundary conditions. We use the 2D morphodynamic model Eros with a new 2D hydrodynamic model driven by a sequence of flood, a sediment entrainment/transport/deposition model and a bank erosion law. We first evaluate the model against a natural case: the 1999 Mount Adams rock avalanche and subsequent avulsion on the Poerua river fan (West Coast, New Zealand). By adjusting for the unknown sediment supply history, Eros predicts the evolution of the alluvial riverbed during the first post‐landslide stages within 30 cm. The model is subsequently used to infer how the sediment supply volume and rate control the fan aggradation patterns and associated hazards. Our results show that the total injected volume controls the overall levels of aggradation, but supply rates have a major control on the location of preferential deposition, avulsion and increased flooding risk. Fan re‐incision following exhaustion of the landslide‐derived sediment supply leads to sediment transfer and deposition downstream and poses similar, but delayed, hydro‐sedimentary hazards. Our results demonstrate that 2D morphodynamics models are able to capture the full range of hazards occurring in alluvial fans including river avulsion aggradation and floods. However, only ensemble simulations accounting for uncertainties in boundary conditions (e.g., discharge history, initial topography, grain size) as well as model realization (e.g., non‐linearities in hydro‐sedimentary processes) can be used to produce probabilistic hazards maps relevant for decision making. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献