Gravel (largest fragment in this photo is about 4 cm)

A gravel road in Terre Haute, Indiana. Terre Haute ( is a city in Vigo County, Indiana near the state's western border with Illinois.

Gravel being unloaded from a barge

Gravel is rock that is of a certain particle size range. BARGE, the Big August RecGambling Excursion is a yearly convention held in Las Vegas during the first weekend of August In geology, gravel[1] is any loose rock that is larger than two millimeters (2mm) in its largest dimension (about 1/12 of an inch) and no more than 63 millimeters (about 2. Geology (from Greek γη gê, "earth" and λόγος Logos, "speech" lit In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere 5 inches). Sometimes gravel is restricted to rock in the 2-4 millimeter range, with pebble being reserved for rock >4-63 millimeters. A pebble is a clast of rock with a Particle size of 4 to 64 Millimeters based on the Krumbein phi scale of Sedimentology The next smaller size class in geology is sand, which is >0. Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles 063 mm to 2 mm in size. The next larger size is cobble, which is >63 millimeters to 256 millimeters (about 2. 5 to ten inches). One cubic foot (28. 32 dm³) of gravel typically weighs about 100 pounds (45 kg) [2].

Gravel is an important commercial product, used in many applications.

Many roadways are surfaced with gravel, especially in rural areas where there is little traffic. A road is an identifiable route, way or path between two or more places. Rural areas can be large and isolated (also referred to as "the country" and/or "the countryside over the course of time Traffic on Roads may consist of Pedestrians ridden or herded Animals Vehicles Streetcars and other Conveyances either singly Globally, far more roads are surfaced with gravel than with concrete or tarmac; Russia alone has over 400,000 km of gravel-surfaced roads. Tarmac (short for tarmacadam, a Portmanteau for Tar -penetration Macadam) is a type of highway surface, pioneered by John Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending

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. A conglomerate (kɒnˈglɒmərət is a rock consisting of individual stones that have become cemented together 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. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland An ice age is a period of long-term reduction in the Temperature of the Earth 's surface and atmosphere resulting in an expansion of continental Ice sheets

Etymology

The word comes from the French gravelle, meaning 'coarse sand'. French ( français,) is a Romance language spoken around the world by 118 million people as a native language and by about 180 to 260 million people

Types of gravel

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. Lower Saxony ( German: Niedersachsen ch is pronounced before an s --> lies in north-western Germany and is second Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe.

• 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. "Riverine" redirects here For the use of that term in Maritime geography, see there 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. In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere A mesh is a flat semi-permeable barrier made of connected strands of Metal, Fiber, or other flexible/ductile material

• Crushed stone: This is generally limestone or dolomite that has been crushed and graded by screens to certain size classes. Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 Dolomite (ˈdɒləmaɪt is the name of a Sedimentary Carbonate rock and a Mineral, both composed It is widely used in concrete and as a surfacing for roads and driveways, sometimes with tar applied over it. Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag Tar is a viscous black Liquid derived from the Destructive distillation of organic matter Crushed stone may also be made from granite and other rocks. Granite (ˈɡrænɪt is a common and widely occurring type of intrusive, Felsic, igneous rock. A special type of limestone crushed stone is dense grade aggregate, or DGA, also known as crusher 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 1 to 2 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. Placer mining (pronounced "plass-er" refers to the mining of alluvial deposits for Minerals This may be done by open-pit (also called open-cast

• 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. River gravel are small pieces of rounded stone usually no larger than a large coin of a various colors

See also

• Aggregate
• Clay
• Silt
• Sand
• Pebble
• Cobble
• Boulder

External links

• Gravel Watch: Responsible Management of Aggregates