Gravel


Gravel
Gravel (largest fragment in this photo is about 4 cm)
A gravel road in Terre Haute, Indiana
Gravel being unloaded from a barge

Gravel play /ˈɡrævəl/ is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule (>2 to 4 mm or 0.079 to 0.16 in) and cobble (>64 to 256 mm or 2.5 to 10.1 in). One cubic yard of gravel typically weighs about 3000 pounds (or a cubic metre is about 1,800 kilograms).

Gravel is an important commercial product, with a number of applications. Many roadways are surfaced with gravel, especially in rural areas where there is little traffic. Globally, far more roads are surfaced with gravel than with concrete or tarmac; Russia alone has over 400,000 km (250,000 mi) of gravel-surfaced roads. Both sand and small gravel are also important for the manufacture of concrete.

Contents

Geological formation

Large gravel deposits are a common geological feature, being formed as a result of the weathering and erosion of rocks. The action of rivers and waves tends to pile up gravel in large accumulations. This can sometimes result in gravel becoming compacted and concreted into the sedimentary rock called conglomerate. Where natural gravel deposits are insufficient for human purposes, gravel is often produced by quarrying and crushing hard-wearing rocks, such as sandstone, limestone, or basalt. Quarries where gravel is extracted are known as gravel pits. Southern England possesses particularly large concentrations of them due to the widespread deposition of gravel in the region during the Ice Ages.

Modern production

As of 2006, the United States is the world's leading producer and consumer of gravel.[1][2]

Etymology

The word comes from the French gravelle, meaning 'coarse sand'.

Types

Gravel with stones sized roughly between 5 and 15 millimeter.
Disused gravel pit in Lower Saxony, Germany

Multiple types of gravel have been recognized, including:

  • Bank gravel: gravel intermixed with sand or clay.
  • Bench gravel: a bed of gravel located on the side of a valley above the present stream bottom, indicating the former location of the stream bed when it was at a higher level.
  • Creek rock: this is generally rounded, semi-polished stones, potentially of a wide range of types, that are dredged or scooped from river beds and creek beds. It is also often used as concrete aggregate and less often as a paving surface.
  • Crushed rock: rock that is mechanically broken into small pieces then sorted by filtering through different size mesh.
  • Crushed stone: this is generally limestone or dolomite that has been crushed and graded by screens to certain size classes. It is widely used in concrete and as a surfacing for roads and driveways, sometimes with tar applied over it. Crushed stone may also be made from granite and other rocks. A special type of limestone crushed stone is dense grade aggregate, or DGA, also known as crusher run, or colloquially as "crush and run". This is a mixed grade of mostly small crushed stone in a matrix of crushed limestone powder.
  • Fine gravel: gravel consisting of particles with a diameter of 2 to 4 mm.
  • Lag gravel: a surface accumulation of coarse gravel produced by the removal of finer particles.
  • Pay gravel: also known as "pay dirt"; a nickname for gravel with a high concentration of gold and other precious metals. The metals are recovered through gold panning.
  • Pea gravel: gravel that consists of small, rounded stones used in concrete surfaces. Also used for walkways, driveways and as a substrate in home aquariums.
  • Piedmont gravel: a coarse gravel carried down from high places by mountain streams and deposited on relatively flat ground, where the water runs more slowly.
  • Plateau gravel: a layer of gravel on a plateau or other region above the height at which stream-terrace gravel is usually found.
  • River run gravel: naturally deposited gravel found in and next to rivers and streams.

Relationship to plantlife

In locales where gravelly soil is predominant, plant life is generally more sparse.[3] This outcome derives from the inferior ability of gravels to retain moisture, as well as the corresponding paucity of mineral nutrients, since finer soils that contain such minerals are present in smaller amounts.

See also

References


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Synonyms:

Look at other dictionaries:

  • Gravel — Grav el, v. t. [imp. & p. p. {Graveled}or {Gravelled}; p. pr. & vb. n. {Graveling} or {Gravelling}.] [1913 Webster] 1. To cover with gravel; as, to gravel a walk. [1913 Webster] 2. To run (as a ship) upon the gravel or beach; to run aground; to… …   The Collaborative International Dictionary of English

  • Gravel — ist der Familienname von: Camille Gravel (1915–2005), US amerikanischer Politiker Mike Gravel, US amerikanischer Politiker Raymond Gravel, kanadischer Politiker und katholischer Priester Robert de Gravel (1616–1684), französischer Diplomat unter… …   Deutsch Wikipedia

  • Gravel — Grav el, n. [OF. gravele, akin to F. gr?ve a sandy shore, strand; of Celtic origin; cf. Armor. grouan gravel, W. gro coarse gravel, pebbles, and Skr. gr[=a]van stone.] 1. Small stones, or fragments of stone; very small pebbles, often intermixed… …   The Collaborative International Dictionary of English

  • gravel — (n.) early 13c., from O.Fr. gravele sand, gravel, dim. of grave sand, seashore (Mod.Fr. grève), possibly from Celtic *gravo (Cf. Welsh gro coarse gravel, Bret. grouan, Cornish grow gravel ), perhaps ultimately from PIE *ghreu to rub, grind …   Etymology dictionary

  • gravel — ► NOUN ▪ a loose mixture of small stones and coarse sand, used for paths and roads. ► VERB (gravelled, gravelling; US graveled, graveling) ▪ cover with gravel. ORIGIN Old French, from grave shore …   English terms dictionary

  • gravel — [grav′əl] n. [ME < OFr gravelle, dim. of grave, coarse sand, seashore < or akin to Gaul * grava, stone < IE base * ghreu , to rub hard, pulverize > GRIT] 1. a loose mixture of pebbles and rock fragments coarser than sand, often mixed… …   English World dictionary

  • Gravel — Toponyme désignant un lieu gravillonneux ou caillouteux, le nom est notamment porté dans l Orne et dans l Oise. Avec le même sens : Graveau, Graveaud (17), Gravelle (59, 25) …   Noms de famille

  • Gravel —  Pour l’article homophone, voir Gravelle.  Cette page d’homonymie répertorie des personnes (réelles ou fictives) partageant un même patronyme. Gravel est un patronyme fréquent au Québec. La plupart de ceux qui le portent descendent de… …   Wikipédia en Français

  • gravel — gravelish, adj. /grav euhl/, n., v., graveled, graveling or (esp. Brit.) gravelled, gravelling, adj. n. 1. small stones and pebbles, or a mixture of these with sand. 2. Pathol. a. multiple small calculi formed in the kidneys. b. the disease… …   Universalium

  • gravel — I. noun Etymology: Middle English, from Anglo French gravele, diminutive of grave, greve river bank, stony ground Date: 13th century 1. obsolete sand 2. a. loose rounded fragments of rock b. a stratum or deposit of gravel; also a surface covered… …   New Collegiate Dictionary


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