All terms in this list:

arroyo: A water course; a rivulet.

atoll: A type of island consisting of a ribbon reef that nearly or entirely surrounds a lagoon and supports, in most cases, one to many islets on the reef platform.

basalt: A hard rock of varied mineral content; volcanic in origin, it makes up much of the Earth's crust.

bauxite: The principal ore of aluminium; a clay-like mineral, being a mixture of hydrated oxides and hydroxides.

butte: an isolated hill with steep sides and a flat top

cinder cone: A conical deposit of rock fragments around a volcano.

cirque: A curved depression in a mountainside with steep walls, forming the end of a valley; cwm

datum plane: A plane from which angular or linear measurements are reckoned.

dune: A ridge or hill of sand piled up by the wind.

eon: (also temporal æon) Eternity.

epoch: A particular period of history, especially one considered remarkable or noteworthy.

era: A time period of indeterminate length, generally more than one year.

erosion: The result of having been being worn away or eroded, as by a glacier on rock or the sea on a cliff face

eutrophication: The process of becoming eutrophic

fiord: A long, narrow, deep inlet between cliffs.

fissure: a crack or opening, as in a rock

geyser: A boiling natural spring which throws forth at frequent intervals jets of water, mud etc., driven up by the expansive power of steam.

glacier: A large body of ice which flows under its own mass, usually downhill.

gneiss: A common and widely-distributed metamorphic rock having bands or veins.

isograd: a line, either on a map or the surface of the Earth, joining points at which metamorphism reached similar pressures and temperatures; actually the intersection of a surface and that of the Earth

kerogen: any organic matter present in a sedimentary rock that is insoluble in organic solvents; the precursor of oil and natural gas

kimberlite: A variety of peridotite containing a high proportion of carbon dioxide; often contains diamonds.

laccolith: a mass of igneous or volcanic rock found within strata which forces the overlaying strata upwards and forms domes.

lahar: A volcanic mudflow.

leach: A quantity of wood ashes, through which water passes, and thus imbibes the alkali.

lineation: A linear feature in rock, often structural

lithification: The compaction and cementation of sediment into rock.

lithology: The study of rocks, with particular emphasis on their description and classification.

lithosphere: The rigid, mechanically strong, outer layer of the Earth; divided into twelve major plates

lode: A way or path; a road.

luster: Shine, polish or sparkle.

magma chamber: A large underground pool of molten rock lying under the surface of the earth's crust.

mantle: a piece of clothing somewhat like an open robe or cloak, especially that worn by Orthodox bishops

Mesozoic: Of a geologic era within the Phanerozoic eon and comprises the Triassic, Jurassic and Cretaceous periods from about 230 to 65 million years ago when life on earth was dominated by reptiles.

metamorphic: Having been structurally altered as a result of, or resulting from, exposure to intense heat and/or pressure (at the contact zone between colliding plates, for example).

migmatite: any rock of mixed appearance, being an intimate mixture of granite and older rock, specifically from intense metamorphism which partially melts the rock, causing it to recrystallize in a state intermediate between igneous and metamorphic.

moraine: An accumulation of rocks and debris carried and deposited by a glacier.

mudflow: A type of landslide characterized by large flows of mud and water.

mylonite: any rock that has undergone modifications due to dynamic recrystallization following plastic flow

neap tide: The tide which occurs when the Moon is in its first and third quarter; the effects of the Sun and Moon being partially cancelled out this type of tide is of minimum range.

obsidian: a type of black glass produced by volcanos

oolite: A rock consisting of spherical grains within a mineral cortex accreted around a nucleus, often of quartz grains.

ore: Rock that contains utilitarian materials;

pahoehoe: A form of lava flow of basaltic rock, usually dark-colored with a smooth or ropey surface. It is one of two chief forms of lava flow emitted from volcanoes of the Hawaiian type, the other form being aa.

paleoclimate: The climate of the Earth at a specified point in geologic time

Paleozoic: Of a geologic era within the Phanerozoic eon and comprises the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods from about 542 to 250 million years ago, from the age of trilobites to that of reptiles.

Pangaea: A supercontinent that included all the landmasses of the earth before the Triassic period and that broke up into Laurasia and Gondwana.

peat: Soil formed of dead but not fully decayed flora found in bog areas

pediment: A classical architectural element consisting of a triangular section or gable found above the horizontal superstructure (entablature) which lies immediately upon the columns; fronton

pegmatite: A coarsely crystalline igneous or plutonic rock composed primarily of feldspar and quartz, normally with muscovite and/or biotite mica. Often contains other minerals, which may be of economic importance. Common colors are gray, white, and pink.

peridotite: A rock consisting of small crystals of olivine, pyroxene and hornblende; the major constituent of the Earth's mantle.

Precambrian: (geology) Relating to the eons before the Phanerozoic

pumice: A light, porous type of pyroclastic igneous rock, formed during explosive volcanic eruptions when liquid lava is ejected into the air as a froth containing masses of gas bubbles. As the lava solidifies, the bubbles are frozen into the rock.

pyroclastic: Mostly composed of rock fragments of volcanic origin

schist: Any crystalline rock having a foliated structure and hence admitting of ready division into slabs or slates.

scoria: The slag or dross that remains after the smelting of metal from an ore

stratosphere: layer of the earth's atmosphere located above the troposphere and below the mesosphere.

stratovolcano: A tall conical volcano, composed of layers (or strata) of hardened lava, tephra and ash.

talus: (anatomy) The bone of the ankle.

thalweg: The line that connects the lowest points in a valley or river channel, and thus the line of fastest flow along a river’s course.

tuff: A rock composed of compacted volcanic ash varying in size from fine sand to coarse gravel.

wadi: A valley, gully, or stream-bed in northern Africa and southwest Asia that remains dry except during the rainy season.

xenolith: any piece of rock having a different origin to that of the igneous rock in which it is found

zeolite: Any of several minerals, aluminosilicates of sodium, potassium, calcium or magnesium, that have a porous structure; they are used in water softeners and in ion exchange chromatography.