Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке
The Genesis and Blue Star sedimentary rock-hosted gold deposits occur within the 40-mile-long Carlin trend and are located in Eureka County, Nevada. The deposits are hosted within the Devonian calcareous Popovich Formation, the siliciclastic Rodeo Creek unit and the siliciclastic Vinini Formation. The host rocks have undergone contact metamorphism, decalcification, silicification, argillization, and supergene oxidation.
Clay, noun. Old English Cladg. A stiff viscous earth. (Blackies Compact Etymological Dictionary. Blackie & Son, London and Glasgow. 1946. War Economy Standard) Clay: The original Indo-European word was 'gloi-" "gli-' from which came "glue' and 'gluten'. In Germanic this became 'klai-; and the Old English 'claeg" became Modern English "clay'. From the same source came "clammy' and the northern England dialect "claggy' all of which describe a similar sticky consistency. (Oxford English Dictionary and Ayto's Dictionary of Word Origins, Bloomsbury, 1999) Clay." from Old Greek yRia, y2oia "'glue" 72ivfl "slime, mucus "" y2oidq "'anything sticky" 'from L-E. base *glei-, *gli- 'to glue, paste stick together. (Klein E. A comprehensive etymological dictionary of the English language. Elsevier, Amsterdam, 1967; Skeat W. An etymological dictionary of the English language.
Oxford University Press, 1961; Mann S.E. An Indo-European comparative dictionary. Buske Verlag, Hamburg, 1987) <...>
Clays are one of the most important groups of minerals that destroy permeability in sandstones, but they also react with drilling and completion fluids and induce fine-particle migrationduring hydrocarbon production. They are a very complex family of minerals that commonly are mutually intergrown and contain a wide range of solid solutions and form by a wide range of processes. They form under a wide diversity of pressure and temperature conditions, as well as rock and fluid compositional conditions.
This paper is a guide to the X-ray examination of clay minerals; it incorporates background information concerning the principal crystallographic features of clay minerals, and how this is used in the X-ray identification of these minerals, together with laboratory techniques and the application of X-ray diffractometry to the diagnosis of the clay minerals in natural sedimentary materials. <...>
: This paper presents that in expansive clays containing montmorillonites the generalized water flow equation can be described regarding a solid volume as a reference. The water retention curves are derived by calculating both volumetric water content and the chemical potential of water in a stacking model of the 2:l layer. It is pointed out that molecular dynamics simulation is useful to analyze the characteristics of water retention curves, and that a homogenization analysis also is useful to solve the flow problems in an inhomogeneous porous body <...>
The clay minerals are small hydrous layer silicates and are part of the phyllosilicate family. As discussed in Chapter 11, many of the hydrous layer silicates in clays, muds, soils, shales, slates, etc. are coarser than clay (< 2 or < 4 pm). Primarily for this reason I have suggested (Weaver, 1980) using the term physil, which has no size connotation, to refer to the low-temperature ( 5 400°C) hydrous layer silicates.
The researches resulting in this massive book have been initiated by S. Vacaru fifteen years ago when he prepared a second Ph. Thesis in Mathematical Physics. Studying Finsler–Lagrange geometries he became aware of the potential applications of these geometries in exploring nonlinear aspects and nontrivial symmetries arising in various models of gravity, classical and quantum field theory and geometric mechanics. <...>
There is a general consensus that climate change is an ongoing phenomenon. This will inevitably bring about numerous environmental problems, including alterations to the hydrological cycle, which is already heavily influenced by anthropogenic activity. The available climate scenarios indicate areas where rainfall may increase or diminish, but the final outcome with respect to man and environment will, generally, be detrimental. Groundwater will be vital to alleviate some of the worst drought situations. The paper analyses the main methods for studying the relationships between climate change and groundwater, and presents the main areas in which hydrogeological research should focus in order to mitigate the likely impacts.
In recent years media attention has focused on global climate change and the impacts on the human experience that this may cause. This interest has stimulated earth scientists into a re-appraisal of the rates of change seen in the geological record and which, for years, had been taken for granted. Climatic modelling and other palaeoclimate assessments have reversed the geological adage that the 'present is the key to the past' into 'the past may be the key to the future'. This renewed interest was the driving force behind the European Palaeontological Association's Congress in Vienna <...>
