Gravel - Types

Types

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.

Read more about this topic:  Gravel

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