Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке
Intrusion-related gold systems (IRGS) are a newly-defined (1999) deposit classification (based mainly on well-studied deposits in Alaska and Yukon) that is already mired in confusion, nomenclature uncertainty and misapplication. Increasingly, gold deposits are mis-assigned an IRGS classification because: 1) the nomenclature of intrusion-related gold models has been rapidly evolving; 2) the characteristics of the classification are broadly defined to include a wide range of deposit types that overlap with other gold deposit types; and 3) granitoid intrusions are common features of orogenic belts and are an obvious fluid source for any proximal gold occurrence.
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.
A knowledge of clay is important in many spheres of scientific endeavour, particularly in natural sciences such as geology, mineralogy and soil science, but also in more applied areas like environmental and materials science. Over the last two decades research into clay mineralogy has been strongly influenced by the development and application of a number of spectroscopic techniques which are now able to yield information about clay materials at a level of detail that previously would have seemed inconceivable.
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. <...>
