Glossary of Rock and Mineral Terms - W

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watershed

See drainage basin.

water table

The surface that lies between the zone of aeration and the underlying zone

wave-cut bench

A relatively level surface formed when waves erode the base of a cliff, causing the overlying rock to fall into the surf. A wave-cut bench stands above the water and extends seaward from what remains of the cliff.

waxy (luster)

Luster of a mineral in which it appears to be coated by a layer of wax

wave refraction

The process by which a wave approaching the shore changes direction due to slowing of those parts of the wave that enter shallow water first, causing a sharp decrease in the angle at which the wave approaches until the wave is almost parallel to the coast.

weathering

The process by which exposure to atmospheric agents, such as air or moisture, causes rocks and minerals to break down. This process takes place at or near the Earth's surface. Weathering entails little or no movement of the material that it loosens from the rocks and minerals. Rocks that have

welded tuff

A volcanic igneous rock that forms when still-warm tephra accumulates at the Earth's surface. Because the particles are still warm and soft, they can weld together under the weight of overlying deposits, forming a hard rock. wetland A lake, marsh, or swamp that supports wildlife and replenishes the groundwater  system.

wheat sheaf

Aggregate of compact bundles of crystals, slightly radiating and thicker at the top and the bottom than in the center. Appears in the shape of an hourglass.

widmanstaetten lines

Etched crystal faces that are seen on some polished meteorites.

wind abrasion

The process by which wind erodes bedrock through contact between the bedrock and rock particles carried by the wind.

wiry aggregate

Composed of long, slender, curvy, interwoven wires, the individual members are called wires.

wolframates

Group of minerals that are compounds of one or more metallic elements and the tungstate radical (WO4). These minerals are very heavy, soft, and brittle. Usually categorized with the chemically related molybdates, in which they can be partially replaced by. The wolframates are also known as the tungstates.