Loam is a soil with a predominant clay content and a significant amount of sand [1] . Vladimir Ivanovich Dahl defines loam as “soil with a considerable admixture of clay” [2] and gives an example of a peasant proverb: “ Loam will not be plowed in wet clay, it will bind, but you will not raise it in dry land, it sticks together .” [2] [3]
Content
Etymology of the term
The word “loam” means “close to clay, next to clay” and is etymologically divided into two parts as follows: the prefix “su-” , akin to modern Russian prefixes “s-” and “co” , as well as the root “clay- (ok) . " In modern Russian, this word could sound like a soglina (such as a comrade, associate, employee ).
For comparison, you can cite as an example such words as sandy loam (soil close to sand, but not sand), dusk (state close to darkness (gloom), almost darkness), hustle (state close to crush, crowding) , but not yet crowded), cramp (a condition close to trembling, but still not trembling).
Loam classification
The term “loam” is widely used in soil science , engineering geology , soil science and Quaternary geology [4] .
The Geological Explanatory Dictionary [5] states that different researchers put a significantly different meaning into the definition of the term “loam” [4] . Various definitions and classifications are also found in dictionaries.
Geological Explanatory Dictionary
Loam - loose young continental deposits, consisting of particles less than 0.01 mm, contained in approximately 30-50%, and clastic material larger than 0.01 mm, respectively 70-60%. Loam usually contains about 10-30% of clay particles with a diameter of less than 0.005 mm, which determine their main physical and technical parameters. A characteristic feature of loam is usually taken to be a change in the number of ductility in the range from 7 to 17 [4] .
Mountain Encyclopedia
The mountain encyclopedia defines loam as a loose sand-clay sedimentary rock containing 10-30% (by weight) clay particles (less than 0.005 mm in size) and distinguishes the following types in the loam:
- rough sand
- fine sand
- dusty loam
Species are subdivided depending on the content of sand grains of the appropriate size and dusty particles.
More sandy loams contain a significant amount of quartz, while clayey loams contain clay minerals ( kaolinite , illite , montmorillonite , etc.). Sometimes loam is enriched with organic matter and water-soluble salts (in arid regions). The origin of loam is usually continental. Used as a raw material for brick production
Technical Railway Dictionary
The Technical Railway Dictionary, published in 1941, defines loam as fine-grained soil containing more than 10-15% clay particles.
This dictionary also claims that the loam has significant adhesion, low ductility, low water permeability and is easily eroded, as well as the fact that in soils such soils are used as material for subgrade.
The dictionary also advises to distinguish from normal loams loesslike loams with a large number of vertical pores and giving significant and uneven precipitation upon wetting. When erecting structures on loess-like loams, therefore, measures are used to densify them artificially and to block access to water [6] .
Dictionary of Physical Geography
A dictionary on physical geography, published in Moscow in 1983, states that, depending on the particle size distribution and the number of plasticity, loams are divided into light sandy, light dusty, heavy sandy, heavy dusty [7] .
Also, this reference dictionary subdivides loam into three varieties: boulder, loess-like and integumentary.
- Boulder loam - contains boulders in its thickness - rounded fragments of rock from 10 centimeters to 10 meters across. Small boulders are more common in loam.
- Loesslike loam - loose rocks of various origins, similar to loess (non-layered fine-grained and loose *
- Covering loam covers the relief in the area of ancient continental glaciation and in the glacial strip [7] .
GOST classification
GOST describes loam as a sedimentary dispersed rock , consisting of clay, sand and dust particles, with a plasticity number I P = 7-17.
In accordance with GOST 25100-2011 [8] , depending on the yield index, loams are divided into hard I L <0, semi-solid 0 ≤ I L ≤ 0.25, soft plastic 0.25 <I L ≤ 0.5, soft plastic 0.5 <I L ≤ 0.75, fluid plastic 0.75 <I L ≤ 1 and fluid 1 <I L. Depending on the particle size distribution, loams are divided into light sandy, light dusty, heavy sandy, heavy dusty.
See also
- Sandy loam
- Clay
Notes
- ↑ Loam // Ushakov Dictionary
- ↑ 1 2 Loam // Explanatory Dictionary of the Living Great Russian Language : in 4 volumes / auth. V.I. Dahl . - 2nd ed. - SPb. : Printing house of M.O. Wolf , 1880-1882.
- ↑ Dahl's Explanatory Dictionary online . slovardalja.net. - “LOAM m. Or loamy soil, with a considerable admixture of clay. Loam will not be plowed up, it’s mucilous, “but loam cannot be raised, it sticks together. Loamy soil, with a small admixture of clay. Loamy soil, generally related to loam.”. Date of treatment April 30, 2018.
- ↑ 1 2 3 Loam // Geological Explanatory Dictionary
- ↑ Geological Explanatory Dictionary // Explanatory Dictionaries and Encyclopedias.
- ↑ Technical Railway Dictionary. - M .: State Transport Railway Publishing House. N. N. Vasiliev, O. N. Isaakyan, N. O. Roginsky, Ya. B. Smolyansky, V. A. Sokovich, T. S. Khachaturov. 1941 year.
- ↑ 1 2 Dictionary of Physical Geography. - M .: Education , 1983.
- ↑ GOST 25100-2011. Soils. Classification
Literature
- Konishchev V.N. Some features of cover loams of the southeastern part of the Bolshezemelskaya tundra in connection with their genesis. In Sat: “Geographical Issues. permafrost and periglacial morphology. " Moscow State University Publishing House, 1961.
- Mazurov G.P. On the genesis of integumentary deposits. "Scientific. bull. Leningra. University ", 1948, No. 20.
- Mazurov G.P. To the question of the formation of integumentary deposits. Materials on general permafrost. In Sat :: "VII Interdepartmental meeting on permafrost." Publishing House of the Academy of Sciences of the USSR, M., 1959.
- Okhotin V.V., Mazurov G.P. Cover deposits on moraines of the European part of the Soviet Union. "Vestn. Leningra. University ", 1951, No. 4.
- A. Popov. On the Origin of Covering Loams of the Russian Plain. "Izv. USSR Academy of Sciences ”, ser. geography., 1953, No. 5.
- Popov A. I. Ground veins in the north of Western Siberia. “Q. physical geography of the polar countries ”, vol. 2. Publishing house of Moscow State University, 1959.
- Popov A.I. Covering loams and polygonal relief of the Bolshezemelskaya tundra. In Sat: “Q. geographic permafrost and periglacial morphology. " Moscow State University Publishing House, 1961.