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Minerals, rocks and sediments
Published in Richard J. Chorley, Stanley A. Schumm, David E. Sugden, Geomorphology, 2019
Richard J. Chorley, Stanley A. Schumm, David E. Sugden
The sizes of clastic particles are given with reference to the length of three axes (or ‘diameters’) at right angles to one another, where a = the long axis, b = the intermediate axis and c = the short axis. Obviously, the more irregular the particle shape, the more the values of a, b and c diverge, and the more difficult it is to characterize the particle size by the length of any one diameter. Thus although the average particle diameter may be the mean of a, b and c, the sieve-mesh which just traps the particle is marginally smaller than b. Figure 4.4 gives the standard size nomenclature for clastic material. Terms such as gravel, sand and clay create certain problems because of their common association with given mineralogical components (i.e. rock particles and minerals, quartz and clay minerals), and some workers replace them by the purely textural terms rudite, arenite and lutite, giving them compositional prefixes (e.g. quartz arenite, calcilutite, etc.). Particle sizes are determined by individual measurement for those larger than 10 mm diameter by sieving (10–1/10 mm) and by settling velocity (<1/10 mm).
Sedimentary Petrology
Published in Supriya Sengupta, Introduction to Sedimentology, 2017
Sedimentary particles of mechanical (terrigenous) origin are classified according to their size. Particles larger than 2 mm constitute gravel (Latin—rudite), those between 2 and 1/16 mm constitute sand (Latin—arenite), while those finer than 1/16 mm constitute silt and clay (Latin—lutite). Accordingly, sedimentary rocks of mechanical origin are classified broadly into three groups—rudaceous, arenaceous and lutaceous (also called argillaceous). This scheme of classification is followed here for describing rocks of mechanical origin.
Active design in civil tunnelling with sprayed concrete as a permanent lining
Published in E.Stefan Bernard, Shotcrete: Engineering Developments, 2020
The application of a similar structure was installed in Chile, in a tunnel prone to squeezing and swelling rock (Stefanussen 1998). In an area with lutite (rock consisting entirely of particles in silt/clay fractions) and some 800 m rock cover, the criteria for squeezing was met. On this basis, a design criteria for the support pressure of maximum 2.5 MPa was established. Using circular reinforced ribs of sprayed concrete a capacity of 3 MPa per rib was calculated.
Laboratory characterization of residual sludge from natural gas extraction by hydraulic fracturing in the Burgos Basin, Mexico
Published in Bioremediation Journal, 2018
Aracely Maldonado-Torres, Sandra Grisell Mora Ravelo, Eduardo Osorio Hernández, Angeluz Olvera Velona, José Alberto López Santillán, Benigno Estrada-Drouaillet
Hydraulic fracturing is a technique used to extract non-associated natural gas (Chen, Osadetz, and Chen 2015; Wheeler et al. 2015), which is stored in sedimentary formations known as lutite or shale rock (Wang et al. 2015). The procedure consists of injecting a mixture of water, sand and chemicals into the earth’s crust to fracture the shale formations, thereby allowing the gas to be released and recovered at the surface by pumping into excavated wells (Zhang, Sun, and Duncan 2016). The technique increases the capacity of gas extraction (Chen, Osadetz, and Chen 2015; Zhang, Sun, and Duncan 2016) but generates a large amount of waste (Bacchetta 2013; Lenoir and Bataille 2013). Of this waste, the residual sludge contains large amounts of dissolved solids and naturally occurring compounds, such as hydrocarbons, potentially toxic elements (PTEs), benzene-toluene-xylene (BTX) and gamma isotopes, among others (Zagrean 2002; Brown 2014; Zhang, Sun, and Duncan 2016). Thus, residual sludge, which can adversely affect human health (EPA 2015) and the environment (Adams et al. 2015; Moubasher et al. 2015), is considered hazardous waste (Ning et al. 2009; EPA 2015; Bartoszewicz et al. 2016).