Carbonate Rock: rock composed primarily of calcium carbonate; e.g, limestone

Crust: outermost shell or layer of planet Earth

Erosion: the transport (removal) of weathered particles

Faulting: the breaking and displacement (movement) of rock layers

Igneous Rock: rock formed by the crystallization (cooling and hardening) of molten material either when magma cools slowly within the earth's crust (forming coarse-grained granitic rock) or when lava cools rapidly on the earth's surface in contact with either the atmosphere or the sea (forming fine-grained volcanic rock such as basalt or rhyolite)

Karst: a landscape formed form the solution of carbonate rocks. Depressions or pits (sinkholes) and disappearing streams are characteristic of karst areas in temperate regions; below the surface, caves and caverns are common. Karst is well developed in the Valley and Ridge physiographic province of Virginia.

Lithology: type of bedrock; the kinds of rock comprising the substrate

Lithospheric or Tectonic Plate: segment of the earth's crust that moves as a unit.

Metamorphic Rock: rock, initailly either sedimentary or igneous, in which minerals and texture have been significantly altered by heat or pressure (e.g., slate, marble, gneiss, schist, greenstone)

Monadnock: a mountain that is the result of removal of surrounding rocks; an erosional remnant. Buffalo Mountain in Floyd County is nearby example of this type of mountain.

Orogeny: a major mountain-building episode in geologic history

Physiography: the natural configuration of the land surface

Physiographic Province: a contiguous area (i.e., region) characterized by similar elevations, relief, lithology, geologic structure and geologic history.

Relief: the difference in elevation between the highest and lowest points on a given land surface

Rifting: the splitting apart of the earth's crust when it is stretched by tectonic activity. Results in the downfaulting of blocks of crust and creation of flat-floored valleys or troughs known as rift valleys (e.g., Virginia's Triassic lowlands)

Sedimentary Rock: rock formed from particles generally weathered and eroded from pre-existing rock material but also from the deposition of shells and other organic detritus (e.g., carbonate rocks) or the precipitation of salts from solution.

Structure (geologic): the arrangement of bedrock; e.g., horizontal, tilted, folded or faulted

Syncline: a rock fold which is open at the top; a downwarp.

Tectonic: pertaining to crustal movements of the Earth

Topography: all surface features, both physical and cultural

Weathering: the in situ decomposition of bedrock through mechanical (such as freeze-thaw) and/or chemical (such as solution or hydrolysis) processes. Breaking solid rock into small particles.