Different Type of Rocks

Rocks can be classified into one of the four categories on the basis of their formation process  

Sediments Deposition Transportationy Jrosion/Alteration Volcanic rocks 

Igneous rocks (sometimes called magmatic rocks or endogeneous rocks) are rocks resulting from the solidification on cooling of a molten silicate material called magma and occur in a wide variety of forms of different shapes and sizes. The magma is characterized by  

Magma forms at depths of about 15-25 km, where temperatures are in the range of 500-1500°C and lithostatic pressure around 1 GPa (10 kbar). The types of igneous rocks that form from this magma depend generally on three factors  

According to the cooling depth, igneous rocks can be classified into two major subdivisions  

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Over the last seventeen year s the Analytical center at our Institute amassed the actual material on the application of XRF method to the quantitative determination of some major (Mg, Al, P, S, Cl, K, Ti, Mn, Fe) and trace (V, Cr, Co, Ni, Zn, Rb, Sr, Y, Zr, Nb, Mo, Ba, La, Ce, Pb, Th, U) element contents [1, 2]. This paper presents the specific features of developed techniques for the determination of 25 element contents in different types of rocks using new Biaiker Pioneer automated spectrometer connected to Intel Pentium IV. The special features of X-ray fluorescence analysis application to the determination of analyzed elements in various types of rocks are presented. The softwai e of this new X-ray spectrometer allows to choose optimal calibration equations and the coefficients for accounting for line overlaps by Equant program and to make a mathematic processing of the calibration ai ray of CRMs measured by the Loader program. 

Table 5.4 Olivine major element compositions (in weight %). Samples occur in different types of rocks (1) = forsterite from a metamorphosed limestone (2) = hortonolite from an olivine gabbro (3) = fayalite from a pantelleritic obsidian (4) = fayalite from an Fe-gabbro (5) = forsterite from a cumulitic peridotite (6) = forsterite from a tectonitic peridotite. Samples (1) to (4) from Deer et al. (1983) sample (5) from Ottonello et al. (1979) sample (6) from Piccardo and Ottonello (1978). ...

The modern automated sorters (Fig. 8.1) are machines which examine feed lumps on an individual basis, compare the measured properties of each lump with predetermined criteria, and then separate the lumps, using an applied force, into different products according to the measured properties. A sorter treating -120 + 60 mm material typically treats 85-100 t/h and a imit treating -60 + 30 mm material - 30-40 t/h. Ore types treated by sorters aroimd the world include different types of rocks (Mokrousov and Lileev 1979 Salter and Wyatt 1991 Cutmore and Eberhard 2001). These sorters were installed for one of the following duties pre-concentration of plant feed, intermediate product production, finished product production. The main benefits are as follows ... 

The idea of an element as a basic type of material, different from other materials, has been around for at least 2 million years, when the first people to make stone tools appeared on the scene. These early humans chose different types of rock for different tools, knowing that certain kinds of rock were more likely to break into small flakes or keep their sharp edge. Although they probably did not think about the building blocks of the rocks themselves, they knew that the material of some rocks was different from the material of other rocks. 

A convenient way to define the coefficient of permeability, in order to compare its value for different types of rocks, is to determine its empirical value for hydraulic gradients of 45°, that is, for Ah/Al=l. In such cases k=V. 

The question of the distribution of free carbon in Precambrian sedimentary rocks also needs special consideration. Ronov and Migdisov (1970) show that the content in Lower and Upper Proterozoic complexes remained at the same level, but at the boundary of the Proterozoic and Paleozoic there is observed a two-fold increase in the carbon content. However, quantitative data on the carbon content in different types of rocks, including the BIF, are very few. 

Figure 1.1 Ranges of permeabilities and hydraulic conductivities for different types of rock (modified after R. Allan Freeze and John A. Cherry. GROUNDWATER, 1979, p. 29. Reprinted by permission of Prentice Hall, Englewood Cliffs, New Jersey).

The thermal conductivity of a porous medium is a function of density, porosity, grainsize, shape, cementation, mineral composition and nature of the pore fillers (Somerton, 1992), i.e. the thermal conductivity is different for different types of rock. The heat flow in an inhomogeneous porous medium under conductive equilibrium conditions is given by... 

Erionite occurs in different types of rocks, rarely in pure form. It occurs in two major morphotypes, a short fiber form. Erionite s name came from erion , the Greek work for wool, because of its white, fibrous, wool-like appearance. 

The major exposure of the population to natural radiation arises from inhalation of the short-lived radioactive progeny of the radioactive noble gas radon-222, which in turn is a sixth-generation radioactive decay product of natural uranium. The amount of radon-222 present in the air depends on many factors (e.g., gas permeability in soil and rock, relative humidity, and barometric pressure) but is necessarily linked to the geological concentration of the uranium parent radionuclide. There is about an eightfold range of concentrations of uranium in different types of rocks and soils. 

Table 8.1 Different types of rock coatings (adapted from Dorn, 1998)...

Table 8.1 Proportion of oleic acid used in different types of rocks ...

Groundwater in Asia occurs in many different type of rocks. These range from ancient crystalline basement rocks, which store minor quantities of water in their shallow weathered andjointed layers, to alluvial plain sediments, which may extend to depths of several hundred meters and contain enormous volumes of water (ESCAP, 2000). The Asian region has vast groundwater reservoirs in some areas, which receive extensive amounts of water from abundant recharge available during rainy seasons. 

In this paper the compressive strength/elastic modulus of the jointed rock mass was estimated as a function of intact rock strength/modulus and joint factor. The joint factor reflects the combined effect of joint frequency, joint inclination and joint strength. Therefore, having known the intact rock properties and the joint factor, jointed rock properties can be estimated. The test results indicated that the rock mass strength decreases with an increase in the joint frequency and a sharp transition was observed from brittle to ductile behaviour with an increase in the number of joints. It was also found that the rocks with planar anisotropy exhibit the highest strength in the direction perpendicular to the anisotropy and the lowest at an inclination of 30o-45o in jointed samples. The anisotropy of the specimen influences the dynamic elastic modulus more than the static elastic modulus. The results were also compared well with the published works of different authors for different type of rocks. 

Variability of sample type . Many different types of rock or sediment may be encountered within a single geological survey. These materials may present contrasting challenges for preparation and analysis. Comparisons of analyte concentration in different matrices have lower confidence than analyses of analyte concentrations in similar matrices. 

Many are dimensionless and are often referred to collectively as either the "capillary number" or the "critical displacement ratio" by workers dealing with surface phenomena and oil recovery. Although the experimental data are still rather limited as far as capillary number results are concerned for different types of rocks, the consensus by the various workers is good. Different authors have examined the pore dimensions and geometry in both synthetic and real systems to calculate the critical value of the... 

On Darwin s landscape, 1 cannot predict where each rock will fall, but I can predict how the law of gravity pulls different types of rock, and how the laws of chemistry cause some to fragment with particular shapes. I could also predict that an architect would use bigger, more square-edged rocks as a foundation. The architect would have a range of choices within that, but I can predict that the building would need to stand up. 

Portnov A, Gorobets B (1969) Luminescence of apatite from different types of rocks. Dokl Akad Nauk SSSR Seriya Geol 184 199-202... 

By monitormg temperature inertia in a diurnal cycle, information on different types of rocks, for example, can be obtained from the heat dynamics. In general, comparing satellite imagery from difterent times but corrected with precision to the same geometry, a lot of information on changing processes on a local or a global scale can be obtained. The techniques and applications of multi-spectral analysis from space have been discussed, for example, in [6.184-6.188]. 

In areas which have been subjected to intensive glaciation, such as Scotland, the soils are often derived from mixtures of different types of rock and the nature of the parent material may vary, even within farm fields. In such circumstances, prediction of soil trace-element content may be very difficult. A further complication is that the total content of any trace element in the soil normally gives little indication of the availability of that element to plants, and Mitchell and co-workers have published several papers dealing with the factors affecting availability [6,84,85]. On the other hand, there are extensive regions in the world, for example, in central Australia, in the mid-west of the USA and in the steppes in the Soviet Union, where the soil is almost uniformly derived over wide areas from the same kind of parent material and where neither the total nor the available levels of trace elements vary very much. 

Vosteen, H.D., Schellschmidt, R., 2(X)3. Influence of temperature on thermal conductivity, thermal capacity and thermal diffusivity for different types of rock. Phys. Chem. Earth 28, 499-509. 

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