gravel

Gravel originates from the cyclical deposition of iron oxide in the mottled layer of the soil.

When the soil is wet, the ferrous iron in the soil moves up the profile by diffusion, as atmospheric oxygen simultaneously diffuses down through the water. A chemical reaction occurs where these meet, producing insoluble ferric iron. As this process proceeds over several cycles, deposition of the ferric iron continues around a particle. This forms concentric layers and causes it to be extremely rounded. When the mottled zone weathers these particles remain as gravel.

Due to the extreme roundness of the gravel pieces, walking on the stuff is actually fairly slippery and it easy to loose your footing, especially walking up or down a slope.

In Australia, gravel is used as surface for unsealed roads, particularly found in country areas.

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&amac;van stone.]

1.

Small stones, or fragments of stone; very small pebbles, often intermixed with particles of sand.

2. Med.

A deposit of small calculous concretions in the kidneys and the urinary or gall bladder; also, the disease of which they are a symptom.

Gravel powder, a coarse gunpowder; pebble powder.

© Webster 1913.

Grav"el, v. t. [imp. & p. p. Graveled (?) or Gravelled; p. pr. & vb. n. Graveling or Gravelling.]

1.

To cover with gravel; as, to gravel a walk.

2.

To run (as a ship) upon the gravel or beach; to run aground; to cause to stick fast in gravel or sand.

When we were fallen into a place between two seas, they graveled the ship. Acts xxvii. 41 (Rhemish version).

Willam the Conqueror . . . chanced as his arrival to be graveled; and one of his feet stuck so fast in the sand that he fell to the ground. Camden.

3.

To check or stop; to embarrass; to perplex.

When you were graveled for lack of matter. Shak.

The physician was so graveled and amazed withal, that he had not a word more to say. Sir T. North.

4.

To hurt or lame (a horse) by gravel lodged between the shoe and foot.

© Webster 1913.