Measurement of grain sizes of sedimentary rock.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



also granulometric analysis, or mechanical analysis, the set of procedures for determining the granulometric composition of loose rocks, soils, and artificial materials.

Rock fragments (such as pebbles, gravel, and sand), clay, and other clayey rocks and soils consist of mineral and organic particles of different sizes. These particles are divided on the basis of size into definite complexes or fractions. The separation of large-grain materials is done by means of a set of sieves (sifters). The separation of sand fractions (with particle dimensions from hundredths of a millimeter to 2–3 mm) is done by sifting (with washing or without it) through a set of sieves with appropriate openings (so-called sieve analysis). Separation of smaller particles is done by hydraulic methods based on either the difference in the speed of sedimentation of particles of different sizes in placid water or on the ability of jets of water flowing at different speeds to draw off particles of different sizes. There are also other methods, such as dispersion analysis and sedimentation analysis. The precision of these methods is not more than 1 percent. To a large extent results depend on the method of preparing the mixture for analysis. Sometimes the samples being analyzed are simply soaked in water in order to avoid disaggregation of the aggregates of very small particles present in them. In other cases, on the contrary, an effort is made to break these aggregates down as far as possible by boiling in advance and treating the samples with various agents. Furthermore, an essential condition for correct analysis is preventing coagulation of the suspension during the analysis. In order to avoid this, substances (so-called stabilizers) that prevent coagulation are added to the suspension being analyzed.

The results of the analysis are represented graphically or in the form of numerical tables. The most common charts are histograms, cumulative curves, and distribution curves. Distribution curves are constructed so that the dimensions of the fractions are laid out on the x-axis and their content in percentages is measured on the y-axis. For the cumulative curve, unlike the distribution curve, cumulative percentages are laid out on the y-axis. The analysis can also be represented in the form of a point on a triangle. (The closer the point is to a certain apex of the triangle the more there is in the given rock of the fraction corresponding to this apex.)


Rukhin, L. B. Granulometricheskii metod izucheniia peskov. Leningrad, 1947.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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This acquisition follows an extensive due diligence program, including mapping, sampling and granulometry studies.
In Carajas, as the iron content is already high (above 64%), the ore is only crushed and sieved, so it can be classified by size (granulometry).
Soil granulometry, particle density ([D.sub.p]), plasticity (LP) and liquidity (LL) limits of the studied Ultisol Layer Sand Silt Clay [D.sub.p] LP LL (m) (g [kg.sup.-1]) (Mg [m.sup.-3]) (%) 0-0.20 824 32 144 2.62 12.50 12.50 0.20-0.40 812 30 158 2.62 17.50 17.50 Table 2.
This can be explain because, according Nogami and Villibor (1995) the index c' which correlates the granulometry of the material indicates for two mixtures a non-plastic sandy texture, since its values are less than 1.0 (c' < 1.0).
Soil physical characteristics Granulometry (g.[kg.sup.-1]) Value Sand 64.24 Granulometry (g.[kg.sup.-1]) Silt 30.67 Clay 5.09 Textural class Sandy loam Bulk 2.83 Density (g/[cm.sup.3]) Particle 1.52 Total porosity (%) 46.29 Field capacity (%) (-0.33 atm) 4.37 Permanent wilting point (%) (-15 ctm) 2.92 Available water (%) 1.45 Table 2.
Influence of sediment granulometry and salinity on the composition of an estuarine fish assemblage in the Mexican Tropical Pacific
Beans quality inspection using correlation-based granulometry. Engineering Applications of Artificial Intelligence.
The self-centering of burrs resulting from the exclusive design, generates consistent granulometry adapted to all brewing methods from Ibrik, Espresso, Pour-over to French-Press.
Sediment samples were dried in an oven at 50 [degrees]C, and the granulometry analysis was subsequently performed using sieving techniques (Suguio, 1973).
[27] worked on a synthesized geopolymer with fly ash at a granulometry of 4.7 ^m and studied the geopolymerization reaction using metakaolin with an average diameter of 18 [micro]m.