Evolution of melt composition during intrusion of basalts into a silicic magma chamber   总被引：3，自引：0，他引：3  

P. Yu. Plechov  I. S. Fomin  O. E. Mel’nik  N. V. Gorokhova 《Moscow University Geology Bulletin》2008,63(4):247-257

The article describes heat exchange between basaltic and rhyolite melts accompanied by fractional crystallization of phases in a basaltic melt. A numerical model has been developed for the homogenization mechanism of magma composition during intrusion of basaltic magma batches into felsic magma chambers. The results of numerical modeling demonstrate that the time needed for cooling the basalts and their fractionation to rhyolite melts is much shorter than the time required for chemical interaction based on diffusive mechanisms.  相似文献   

High-level radioactive waste disposal in Sweden: Hydrogeochemical characterisation and modelling of two potential sites     

M. Gascoyne 《Applied Geochemistry》2008

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Experimental study of the fine structure of the wind field near a rough surface     

I. N. Ivanova  O. N. Mel’nikova  T. A. Nivina  K. V. Pokazeev 《Izvestiya Atmospheric and Oceanic Physics》2006,42(5):646-652

The air-flow velocity field near the water surface is studied in the zone of wind-wave intensification. Caused by a periodic separation of eddies, a nonzero time-averaged value of the wind velocity in the near-water streamline is detected at the leading slope of the wave. The distribution of pressure along the wave with allowance for the vertical velocity shear and disturbances produced by eddies and a periodic deceleration of the viscous layer was calculated with the aid of the Cauchy-Lagrange integral. This procedure made it possible to calculate the growth rate of the wave amplitude, whose value was found to be close to its experimental value at the initial stage of acceleration.  相似文献   

Physicochemical parameters of the crystallization of plagioclases in basaltic rocks from guyots of the Magellan Seamounts (Pacific Ocean)     

V. Yu. Prokof’ev  V. V. Avdonin  M. E. Mel’nikov 《Doklady Earth Sciences》2008,421(2):995-999

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Vegetation influences on water yields from grassland and shrubland ecosystems in the Chihuahuan Desert     

Mel Neave  Athol D. Abrahams 《地球表面变化过程与地形》2002,27(9):1011-1020

This study examines runoff generated under simulated rainfall on Summerford bajada in the Jornada Basin, New Mexico, USA. Forty‐five simulation experiments were conducted on 1 m² and 2 m² runoff plots on grassland, degraded grassland, shrub and intershrub environments located in grassland and shrubland communities. Average hydrographs generated for each environment show that runoff originates earlier on the vegetated plots than on the unvegetated plots. This early generation of runoff is attributed to soil infiltration rates being overwhelmed by the rapid concentration of water at the base of plants by stemflow. Hydrographs from the degraded grassland and intershrub plots rise continuously throughout the 30 min simulation events indicating that these plots do not achieve equilibrium runoff. This continuously rising form is attributed to the progressive development of raindrop‐induced surface seals. Most grassland and shrub plots level out after the initial early rise indicating equilibrium runoff is achieved. Some shrub plots, however, display a decline in discharge after the early rise. The delayed infiltration of water into macropores beneath shrubs with vegetation in their understories is proposed to explain this declining form. Water yields predicted at the community level indicate that the shrubland sheds 150 per cent more water for a given storm event than the grassland. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Evolution of Redox Conditions and Groundwater Composition in Recharge-Discharge Environments on the Canadian Shield   总被引：2，自引：0，他引：2  

M. Gascoyne 《Hydrogeology Journal》1997,5(3):4-18

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The Stress–Strain State of Recent Structures in the Northeastern Sector of the Russian Arctic Region     

Imaeva  L. P.  Imaev  V. S.  Mel’nikova  V. I. 《Doklady Earth Sciences》2018,479(1):371-374

Doklady Earth Sciences - Complex research to determine the stress–strain state of the Earth’s crust and the types of seismotectonic destruction for the northeastern sector of the...  相似文献   

Studies from the drifting ice station in April 2008     

I. A. Mel’nikov 《Oceanology》2008,48(6):888-890

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Equipment and procedure improvements for a lightweight,inexpensive, percussion core sampling system     

Mel A. Reasoner 《Journal of Paleolimnology》1993,8(3):273-281

This paper describes improvements for an inexpensive, lightweight percussion core sampling system and presents examples of recovered core. The system has proven most effective in remote settings where the weight of a coring system may be a constraint. Cores of up to 5.5 m in length have been recovered and the system has functioned successfully in water depths to 200 m. The system weighs approximately 25 kg and costs less than $450.00 (US).The percussion corer is designed for operation from a stable ice-pack surface. The core barrel assembly is lowered through the water column and driven into sediment with a weighted driver. A secondary line is used to raise and drop the driver. The driver is guided to the core barrel assembly by the main line. Cores are retrieved by a simple pulley system anchored to the ice pack.  相似文献   

The Hydrogeochemistry Of Fractured Plutonic Rocks In The Canadian Shield     

M. Gascoyne  D. C. Kamineni 《Hydrogeology Journal》1994,2(2):43-49

The composition of groundwater has been determined in selected granitic, gabbroic and gneissic plutons in the Canadian Shield as part of the Canadian Nuclear Fuel Waste Management Program. A similar geochemical evolution of the groundwater is seen with increasing depth or with flow along the hydraulic gradient, irrespective of rock type. This pattern is comparable to that seen in mine groundwaters from throughout the Canadian Shield. Near-surface groundwaters are typically dilute, slightly alkaline and Ca-(Na)-HCO₃ in composition. They evolve to higher pH, Na-(Ca)-HCO₃ compositions along the flow path because of interaction with plagioclase, calcite precipitation and ion exchange on clay minerals. At greater depths (>≈200 m), groundwater salinity increases as a result of the dissolution of Cl-rich salts in the rock matrix and, in certain areas, mixing with Na-Cl brines from seawater or basinal formation water. Stable and radioactive isotopic data for the groundwaters help to interpret these characteristics and indicate high residence times for the deeper, saline groundwater.

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3 évoluent du fait des interactions avec les plagioclases, de la précipitation de la calcite et des échanges d'ions avec les argiles. Aux plus grandes profondeurs (>≈200 m), l'accroissement de la salinité de l'eau souterraine est provoqué par la dissolution de chlorures de la matrice et, en certains endroits, par le mélange avec des saumures à Na et Cl d'eau de mer ou d'eau de formation de bassin. Les données des isotopes stables et radioactifs des eaux souterraines aident à interpréter leurs caractéristiques; elles indiquent des temps de séjour longs pour les eaux souterraines salées, les plus profondes.

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