{"id":827,"date":"2017-08-27T19:44:28","date_gmt":"2017-08-27T23:44:28","guid":{"rendered":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/back-matter\/glossary\/"},"modified":"2023-02-03T18:44:55","modified_gmt":"2023-02-03T23:44:55","slug":"glossary","status":"publish","type":"back-matter","link":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/back-matter\/glossary\/","title":{"raw":"Glossary","rendered":"Glossary"},"content":{"raw":"

A<\/a> B<\/a> C<\/a> D<\/a> E<\/a> F<\/a> G<\/a> H<\/a> I<\/a> J<\/a> K<\/a> L<\/a> M<\/a> N<\/a> O<\/a> P<\/a> Q<\/a> R<\/a> S<\/a> T<\/a> U<\/a> V<\/a> W<\/a> X<\/a> Y<\/a> Z<\/a><\/h1>\r\n

<\/a>A<\/h2>\r\naa<\/strong>\u00a0 a lava flow that solidifies with a blocky high-relief surface\r\n\r\nablation<\/strong>\u00a0 melting of ice in the context of glaciation\r\n\r\nablation till<\/strong>\u00a0 till that is formed when englacial and supraglacial sediments are deposited because the ice that was supporting them melts\r\n\r\nabyssal plain<\/strong>\u00a0 the flat surface of the deep ocean, typically beyond the limits of the continental slopes\r\n\r\nabyssal pelagic zone<\/strong>\u00a0 the deeper parts of the ocean, between 4000 and 6000 m.\r\n\r\naccretion<\/strong> (plate tectonics) the process by which continental blocks (terranes) are added to existing continental areas\r\n\r\naccretion<\/strong> (planetary) the process by which solid celestial bodies are added to existing bodies during collisions\r\n\r\nacid rock drainage<\/strong> (acid mine drainage) the production of acid from oxidation of sulphide minerals (especially pyrite) in either naturally or anthropogenically exposed rock\r\n\r\naeolian<\/strong>\u00a0 processes related to transportation and deposition of sediments by wind\r\n\r\naerobic<\/strong> processes that take place in the presence of abundant oxygen\r\n\r\naerosol<\/strong>\u00a0 an aggregate of fine solid particles or a small droplet of liquid suspended in the air\r\n\r\naftershock<\/strong> an earthquake that can be shown to have been caused by another earthquake\r\n\r\naggregate<\/strong> unconsolidated materials (typically sediments) that are used in the construction industry\r\n\r\nalbedo<\/strong>\u00a0 the reflectivity of a surface of a planet (expressed as the percentage of light that reflects)\r\n\r\nalbite<\/strong>\u00a0 sodium-rich plagioclase feldspar\r\n\r\nalpine glacier<\/strong> a glacier formed in a mountainous region and confined to a valley (same as valley glacier)\r\n\r\namphibole<\/strong>\u00a0 a double-chain ferromagnesian silicate mineral (e.g., hornblende)\r\n\r\namphibolite<\/strong> a foliated metamorphic rock in which the mineral amphibole as an important component\r\n\r\namplification<\/strong>\u00a0 in the context of seismic shaking the process by which the amplitude of the seismic waves are enhanced\r\n\r\namplitude<\/strong> for any type of wave, the difference in height between a crest and the adjacent trough\r\n\r\nanaerobic<\/strong>\u00a0 processes that take place without oxygen\r\n\r\nandesite<\/strong>\u00a0 a volcanic rock of intermediate composition\r\n\r\nanion<\/strong>\u00a0 a negatively charged ion\r\n\r\nangular unconformity<\/strong>\u00a0 a geological boundary at the base of a sedimentary layer where the sedimentary rock beneath has been tilted or folded and then eroded\r\n\r\nanorthite<\/strong>\u00a0 calcium-rich plagioclase feldspar\r\n\r\nAntarctic Bottom Water<\/strong>\u00a0 water at abyssal depths in the ocean that forms from the sinking of dense cold water adjacent to Antarctica\r\n\r\nanticline<\/strong>\u00a0 an upward fold where the beds are known not to be overturned\r\n\r\nanthracite<\/strong>\u00a0 a high grade of coal (92 to 98% carbon) that is formed from deep burial and weak metamorphism\r\n\r\nanthropogenic<\/strong>\u00a0 resulting from the influence of humans\r\n\r\nantiform<\/strong> an upward fold where it is not known if the beds have been overturned\r\n\r\napparent polar wandering path<\/strong>\u00a0 a path of seeming varying magnetic pole positions defined by paleomagnetic data, which is in fact an artefact of the motion of contients\r\n\r\naphanitic<\/strong>\u00a0 an igneous texture characterized by crystals that are too small to see with the naked eye\r\n\r\naquifer<\/strong> a body of rock or sediment that has sufficient permeability to allow it to be used as a source of groundwater\r\n\r\naquitard<\/strong>\u00a0 a body of rock or sediment that has insufficient permeability to allow it to be used as a source of groundwater\r\n\r\narch<\/strong>\u00a0 a rock weathering remnant in the form of an arch (typically along a coast and resulting from wave erosion)\r\n\r\narenite<\/strong>\u00a0 a sandstone with less than 15% silt and clay\r\n\r\nar\u00eate<\/strong> \u00a0 a sharp ridge that separates adjacent glacially carved valleys\r\n\r\narkose<\/strong>\u00a0 a sandstone with more than 10% feldspar and more feldspar than lithic fragments\r\n\r\narkosic arenite<\/strong>\u00a0 an arkose with less than 15% clay\/silt matrix\r\n\r\nartesian well<\/strong>\u00a0 a well that is completed in a confined aquifer and in which the water level in the well rises above the top of the aquifer\r\n\r\nasteroid<\/strong>\u00a0 a rocky body orbiting the Sun\r\n\r\nasteroid belt<\/strong>\u00a0 the region between the orbits of Mars and Jupiter that is populated with many asteroids\r\n\r\nasthenosphere<\/strong>\u00a0 the part of the mantle, from about 100 to 200 km below surface, within which the mantle material is close to its melting point, and therefore relatively weak\r\n\r\nasymmetrical<\/strong> (folds) where the two sides of the fold make significantly different angles with respect to the axial plane\r\n\r\natoll<\/strong>\u00a0 a ring-shaped carbonate (or coral) reef or series of islands\r\n\r\natomic mass<\/strong>\u00a0 the total number of neutrons plus protons in an atom\r\n\r\natomic number<\/strong>\u00a0 the total number of protons in an atom\r\n\r\nattitude<\/strong>\u00a0 the orientation of a sloping geological feature, such as a bedding plane or fracture\r\n\r\naureole<\/strong>\u00a0 a zone of metamorphism around a source of heat such as a magma body\r\n\r\naxial plane<\/strong>\u00a0 a plane that can be traced through all of the hinge lines of a fold\r\n

<\/a>B<\/h2>\r\nback reef<\/strong>\u00a0 the zone of shallow water on the shore-side of a reef\r\n\r\nbackground<\/strong> (geochemistry)\u00a0 the typical level of an element in average rocks or sediments\r\n\r\nbackwash<\/strong>\u00a0 the wash of wave water down the slope of a beach\r\n\r\nbanded iron formation<\/strong>\u00a0 an iron-bearing sedimentary rock that is rich in minerals such as hematite and magnetite, and interbedded with chert stained red by hematite\r\n\r\nbank-full stage<\/strong>\u00a0 the water level of stream when it is in flood and just about to flow over its banks\r\n\r\nbarrier reef<\/strong>\u00a0 a carbonate (or coral) reef that forms a barrier to waves along a coast\r\n\r\nbasal sliding<\/strong>\u00a0 the motion of glacial ice along the base of a glacier that is warm enough to have liquid water\r\n\r\nbasalt<\/strong>\u00a0 a volcanic rock of mafic composition\r\n\r\nbase level<\/strong> (stream) the base level is the lowest level that a stream can erode down to, as defined by the ocean, a lake or another stream that it flows into\r\n\r\nbatholith<\/strong> an irregular body of intrusive igneous rock that has an exposed surface of at least 100 km2<\/sup>bathypelagic zone<\/strong>\u00a0 the moderately deep parts of the ocean, between 1000 and 4000 m.\r\n\r\nbaymouth bar<\/strong> a spit that extends across the mouth of a bay\r\n\r\nbeach face<\/strong> the part of the beach that is relatively steep and lies between the high and low tide levels\r\n\r\nbed<\/strong>\u00a0 a sedimentary layer\r\n\r\nbed load<\/strong>\u00a0 the fraction of a stream\u2019s sediment load that typically rests on the bottom and is moved by saltation and traction\r\n\r\nbedding<\/strong> repeated layering in a sedimentary rock\r\n\r\nbentonite<\/strong>\u00a0 a smectite clay that has strong swelling properties and is effective at absorbing dissolved ions\r\n\r\nberm<\/strong>\u00a0 a flat area of a beach in the backshore area (above the high tide level)\r\n\r\nbig-bang theory<\/strong> the theory that the universe started by expanding suddenly from a single point approximately 13.77 billion years ago\r\n\r\nbiochemical sedimentary rock<\/strong>\u00a0 a rock formed when biological processes cause ions to precipitate (e.g., when organisms make shells of calcite or silica)\r\n\r\nbiotite<\/strong>\u00a0 a sheet-silicate mineral (mica) that includes iron and or magnesium, and is therefore a ferromagnesian silicate\r\n\r\nbiozone<\/strong>\u00a0 a stratigraphic interval that can be defined on the basis of a specific fossil\r\n\r\nbituminous coal<\/strong>\u00a0 a medium-grade type of coal with 70 to 92% carbon\r\n\r\nblueschist<\/strong>\u00a0 1. (metamorphic rock) a schist with blue colouring due to the presence of the mineral glaucophane. Formed in subduction zones. 2. (metamorphic facies) a facies characterized by relatively low temperatures and high pressures, such as can exist within a subduction zone\r\n\r\nbody wave<\/strong>\u00a0 a seismic wave that travels through rock (e.g., a P-wave or an S-wave)\r\n\r\nboulder<\/strong>\u00a0 a sediment clast with a diameter of at least 256 mm\r\n\r\nBowen's reaction series<\/strong>\u00a0 the scheme that defines the typical order of crystallization of minerals from magma as the magma cools\r\n\r\nbraided<\/strong>\u00a0 a stream pattern which is characterized by abundant sediment and numerous intertwining channels around bars\r\n\r\nbreakwater<\/strong> a structure built offshore in order to deflect the energy of waves\r\n\r\nbreccia<\/strong>\u00a0 a sedimentary or volcanic rock texture characterized by angular clasts\r\n\r\nbrunisol<\/strong>\u00a0 a relatively immature forest soil, lacking in well-defined horizons\r\n\r\nburial<\/strong>\u00a0 when a layer of sediment is covered by subsequent sediment accumulation\r\n

<\/a>C<\/h2>\r\ncaldera<\/strong>\u00a0 a volcanic depression that forms when part of the volcano collapses into an empty magma chamber\r\n\r\ncaliche<\/strong>\u00a0 a white calcium-carbonate rich layer within soils in arid regions\r\n\r\ncalving<\/strong>\u00a0 the loss of ice from the front of a glacier by collapse into water\r\n\r\nCanadian Shield<\/strong>\u00a0 the exposed part of the continent Laurentia\r\n\r\ncarbonate<\/strong> a mineral for which the anion is CO3<\/sub>-2<\/sup>carbonate compensation depth<\/strong>\u00a0 the depth in the ocean below which carbonate minerals are soluble\r\n\r\ncation<\/strong>\u00a0 a positively charged ion\r\n\r\ncementation<\/strong>\u00a0 the process by which minerals are precipitated between grains in sediments, locking the grains together\r\n\r\nCenozoic<\/strong>\u00a0 the most recent of the eras, representing the past 65.5 Ma of geological time\r\n\r\nchemical<\/strong> sedimentary rock<\/strong>\u00a0 a sedimentary rock comprised of material that was transported as ions in solution, then precipitated by inorganic means (e.g., precipitation triggered by evaporation)\r\n\r\nchemical weathering<\/strong>\u00a0 chemical reactions at Earth's surface which break down rocks and minerals\r\n\r\nchernozem<\/strong>\u00a0 black soil typical of grasslands in cold climates such as the Canadian Prairies\r\n\r\nchert<\/strong>\u00a0 very fine-grained sedimentary rock formed almost entirely of silica\r\n\r\nchilled margin<\/strong>\u00a0 edges of a pluton which cool rapidly through contact with country rock, resulting in finer grain sizes than in the interior of the pluton\r\n\r\nchlorite<\/strong>\u00a0 ferromagnesian sheet silicate mineral, typically present as fine crystals and forming from the low-temperature metamorphism of mafic rock\r\n\r\ncinder cone<\/strong>\u00a0 steep-sided volcano comprised almost entirely of loose rock fragments, and typically formed during a single eruptive event\r\n\r\ncirque<\/strong>\u00a0 a steep-sided semi-circular basin eroded by an alpine glacier at the head of its valley\r\n\r\nclast<\/strong>\u00a0 a sedimentary fragment of mineral or rock\r\n\r\nclastic sedimentary rock<\/strong>\u00a0 a sedimentary rock comprised of material that was transported as clasts or fragments\r\n\r\nclay<\/strong>\u00a0 sediment particle that is less than 1\/256 mm in diameter\r\n\r\nclay mineral<\/strong>\u00a0 a hydrous sheet-silicate mineral that typically exists as clay-sized grains\r\n\r\nclaystone<\/strong>\u00a0 a sedimentary rock comprised mostly of clay-sized grains\r\n\r\ncleavage<\/strong>\u00a0 tendency for a mineral to break along smooth planes that are predetermined by its lattice structure\r\n\r\nclimate feedback<\/strong>\u00a0 a case in which the effects of a climate forcing trigger other changes which either amplify or mute the effects of the initial forcing\r\n\r\nclimate forcing<\/strong>\u00a0 a mechanism, such as a change in greenhouse gas levels, that causes the climate to change\r\n\r\ncoal\u00a0 <\/strong>an organic sedimentary rock formed by the compression and heating of vegetative organic matter. Types of coal include lignite, bituminous coal, and anthracite.\r\n\r\ncoal-bed methane<\/strong>\u00a0 methane that is trapped within the pores of coal within a coal seam\r\n\r\ncoastal straightening<\/strong>\u00a0 the tendency for an irregular coast to be straightened over time by coastal erosion processes\r\n\r\ncobble<\/strong>\u00a0 sediment particle that is between 64 and 256 mm in diameter\r\n\r\ncol<\/strong>\u00a0 the low point or pass along a ridge between two glacial valleys\r\n\r\ncolumnar jointing<\/strong>\u00a0 the fractures in volcanic rock forming columns that are typically 6-sided, resulting from cooling and contraction of the rock\r\n\r\ncomposite volcano (or stratovolcano)<\/strong>\u00a0 a volcano that is constructed of alternating layers of pyroclastic debris and lava flows\r\n\r\nconcentrate<\/strong> (mining)\u00a0 a product of ore processing that includes a specific ore mineral, separated from the rest of the rock\r\n\r\nconcordant<\/strong>\u00a0 parallel to pre-existing layering or foliation within a rock\r\n\r\ncone of depression<\/strong>\u00a0 the depression of the water table around a well that is heavily pumped\r\n\r\nconfined aquifer<\/strong>\u00a0 an aquifer that lies below a confining layer\r\n\r\nconfining layer<\/strong>\u00a0 an aquitard that overlies an aquifer and restricts the flow of water down from the surface\r\n\r\nconfining pressure<\/strong>\u00a0 pressure resulting from the weight of overlying rocks\r\n\r\nconglomerate<\/strong>\u00a0 a sedimentary rock that is comprised predominantly of rounded grains that are larger than 2 mm\r\n\r\ncontact metamorphism<\/strong>\u00a0 metamorphism that takes place adjacent to a source of heat, such as a body of magma\r\n\r\ncontinental drift<\/strong>\u00a0 the concept that tectonic plates can move across the surface of the Earth\r\n\r\ncontinental glacier<\/strong>\u00a0 a glacier that covers a significant part of a continent and has an area of at least 50,000 km2<\/sup>continental shelf<\/strong>\u00a0 the shallow (typically less than 200 m) and flat sub-marine extension of a continent\r\n\r\ncontinental slope<\/strong>\u00a0 the steeper part of a continental margin, that slopes down from a continental shelf towards the abyssal plain\r\n\r\ncontractionism<\/strong>\u00a0 the now discredited theory that mountain ranges formed as a result of the contraction of the Earth\r\n\r\nconvergent boundary<\/strong>\u00a0 a plate boundary at which the two plates are moving towards each other\r\n\r\nCordilleran Ice Sheet<\/strong>\u00a0 the continental glacier that covered part of western North America, including almost all of British Columbia, part of the Yukon, and part of northern Washington, during the Pleistocene glaciations\r\n\r\ncore<\/strong>\u00a0 the metallic interior part of the Earth, extending from a depth of 2900 km to Earth's centre\r\n\r\ncore-mantle boundary (CMB)<\/strong>\u00a0 the boundary, at 2900 km depth, between the mantle and the core\r\n\r\nCoriolis effect<\/strong>\u00a0 the tendency for moving bodies (e.g., ocean currents) to rotate on the surface of the Earth, clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere\r\n\r\ncosmic microwave background (CMB)<\/strong>\u00a0 a radiation \"fog\" left over from the an early stage in the development of the universe, when the universe was too dense to allow photons to travel far without being scattered\r\n\r\ncountry rock<\/strong>\u00a0 the original rock of a region, into which younger rock (typically igneous) rock has been intruded\r\n\r\ncovalent bond<\/strong>\u00a0 a bond between two atoms in which electrons are shared\r\n\r\ncrater<\/strong>\u00a0 a volcanic depression that is related to a specific volcanic vent\r\n\r\ncraton<\/strong>\u00a0 a region of ancient (typically Precambrian) crystalline rock (equivalent to a shield)\r\n\r\ncreep<\/strong>\u00a0 the very slow (mm to cm per year) flow of unconsolidated material on a gentle slope\r\n\r\ncrest<\/strong>\u00a0 the highest point on a wave\r\n\r\ncrevasse<\/strong>\u00a0 an open fissure on the surface of a glacier\r\n\r\ncross bedding<\/strong>\u00a0 small-scale inclined bedding within larger horizontal beds\r\n\r\ncrust<\/strong>\u00a0 the uppermost layer of the Earth, ranging in thickness from about 5 km (in the oceans) to over 50 km (on the continents)\r\n\r\ncryptocrystalline<\/strong>\u00a0 refers to the texture of a rock or mineraloid in which crystals are so small that they are almost undetectable even with magnification\r\n\r\ncyanobacteria<\/strong>\u00a0 photosynthetic bacteria that evolved in the early Archean\r\n

<\/a>D<\/h2>\r\nD\" layer<\/strong> (d-double-prime layer)\u00a0 a low seismic velocity zone within the basal 200 km of the mantle\r\n\r\ndebris flow<\/strong>\u00a0 a gravity-driven flow of water and sediment that includes a significant proportion of coarse (cobble to boulder) material\r\n\r\ndecline<\/strong> (mining)\u00a0 a sloped tunnel used to access lower parts of a mine with wheeled equipment\r\n\r\ndecompression melting<\/strong>\u00a0 melting (or partial melting) of rock resulting from a reduction in pressure without a significant reduction in temperature\r\n\r\nDeep time (geologic time).<\/strong> The long timescales (millions to billions of years) over which geologic processes happen.<\/span>\r\n\r\ndendritic<\/strong>\u00a0 a pattern of drainage channels that resembles the branches in a tree\r\n\r\ndensity<\/strong>\u00a0 weight per volume of a substance (e.g., g\/cm3<\/sup>)\r\n\r\ndeposition<\/strong>\u00a0 when sediments are dropped out of the medium carrying them, and begin to accumulate in layers\r\n\r\nderanged<\/strong> (drainage)\u00a0 a pattern of drainage channels that is chaotic\r\n\r\ndetrital<\/strong>\u00a0 referring to fragments of rocks or minerals\r\n\r\ndiatom<\/strong>\u00a0 photosynthetic algae that make their tests (shells) from silica\r\n\r\ndifferentiation<\/strong>\u00a0 the un-mixing of a molten planetary body, resulting in the formation of a metallic core and a silicate mantle\r\n\r\ndike<\/strong>\u00a0 a tabular intrusive igneous body that is discordant to any existing layering in the country rock\r\n\r\ndiorite<\/strong>\u00a0 an intermediate intrusive igneous rock\r\n\r\ndip<\/strong>\u00a0 the angle below horizontal at which a sedimentary bed or other feature slopes\r\n\r\ndirected pressure <\/strong>(also, differential stress, directional pressure) pressure which is greater in one direction than in others (e.g., compression, tension)\r\n\r\ndischarge<\/strong>\u00a0 the volume of water flow in a stream expressed in terms of volume per unit time (e.g., m3<\/sup>\/s)\r\n\r\ndischarge area<\/strong>\u00a0 the part of an aquifer where groundwater discharge takes place\r\n\r\ndisconformity<\/strong>\u00a0 a boundary between parallel sedimentary layers where some erosion of the lower layer has taken place\r\n\r\ndiscordant<\/strong>\u00a0 when a geological feature is not parallel to any existing layering in the country rock\r\n\r\ndissolution<\/strong>\u00a0 when water molecules take a substance apart by capturing its ions and keeping them separated (a type of chemical weathering)\r\n\r\ndivalent<\/strong>\u00a0 an ion with a charge or +2 or -2\r\n\r\ndivergent<\/strong>\u00a0 a plate boundary at which the two plates are moving away from each other\r\n\r\ndodecahedron<\/strong> an object with twelve surfaces, such as a garnet crystal\r\n\r\ndolomite<\/strong> a calcium-magnesium carbonate mineral (Ca,Mg)CO3<\/sub>. Also, a rock made out of that mineral (see also dolostone)\r\n\r\ndolomitization<\/strong>\u00a0 the addition of magnesium to limestone during which some or all of the calcium carbonate is converted to dolomite\r\n\r\ndolostone<\/strong>\u00a0 a carbonate rock made up primarily of the mineral dolomite\r\n\r\ndrainage basin<\/strong>\u00a0 the catchment area of a stream, including the area where all surface water drains into the stream\r\n\r\ndrop stone<\/strong>\u00a0 a fragment of rock within otherwise fine-grained sediment that has been dropped from floating ice on a body of water\r\n\r\ndrumlin<\/strong>\u00a0 a streamlined glacial erosional feature comprised of sediments and\/or bedrock\r\n\r\ndyke <\/strong>see dike<\/em>\r\n<\/strong>\r\n

<\/a>E<\/h2>\r\neccentricity<\/strong>\u00a0 (Milankovitch cycles) the degree to which the sun is offset from the geometric centre of the Earth\u2019s orbit\r\n\r\neclogite<\/strong>\u00a0 a garnet-pyroxene-glaucophane bearing rock that is the product of high-pressure metamorphism of oceanic crustal rock, typically within a subduction zone\r\n\r\neffusive<\/strong>\u00a0 a volcanic eruption dominated by the relatively gentle flow of lava\r\n\r\nEl Ni\u00f1o<\/strong>\u00a0 a periodic climatic situation in which warm water extends all or most of the way to the eastern edge of the equatorial Pacific\r\n\r\nelastic deformation<\/strong> deformation from which a material can fully recover if the stress is removed\r\n\r\nelectron<\/strong>\u00a0 sub-atomic particle with a single negative charge\r\n\r\nend moraine<\/strong> sediment deposit that accumulates at the front of a glacier\r\n\r\nenglacial<\/strong>\u00a0 within a glacier, referring especially to sediment carried within the glacial ice\r\n\r\nepicentre<\/strong>\u00a0 the location on the surface vertically above the location (i.e., \u201chypocentre\u201d or \u201cfocus\u201d) where an earthquake takes place\r\n\r\nepipelagic zone<\/strong>\u00a0 the upper layer of water (0 to 200 m) in areas of the open ocean\r\n\r\nepithermal deposit<\/strong>\u00a0 a mineral deposit formed near to surface in an area of hydrothermal activity, typically associated with a body of magma\r\n\r\nequilibrium line<\/strong> (glacier)\u00a0 the line between the zone of accumulation and the zone of ablation (in late summer the equilibrium line is the boundary between snow-covered ice and bare ice)\r\n\r\nequipotential lines<\/strong> (groundwater) \u00a0 lines connecting locations with equal hydraulic head or water pressure\r\n\r\nerosion<\/strong>\u00a0 the process of transporting sediments away from their source\r\n\r\nesker<\/strong>\u00a0 a ridge of sediment deposited by a sub-glacial stream\r\n\r\neustatic sea level change<\/strong>\u00a0 sea level change related to a change in the volume of the oceans, typically because of an increase or decrease in the amount of glacial ice on land\r\n\r\nevaporite<\/strong>\u00a0 a chemical sedimentary rock that forms when evaporation concentrates the ions in a solution to the point where they begin to precipitate out\r\n\r\nexfoliation<\/strong>\u00a0 (weathering) the fracturing of rock that results from a reduction in the pressure when overlying rock is eroded away\r\n\r\nexoplanet<\/strong>\u00a0 a planet that orbits a star other than the sun\r\n\r\nextrusive<\/strong>\u00a0 igneous rock that cooled at Earth's surface\r\n

<\/a>F<\/h2>\r\nfall<\/strong>\u00a0 (mass wasting) the vertical or near-vertical downward movement of rock\r\n\r\nfault<\/strong>\u00a0 boundary in rock or sediment along which displacement has taken place\r\n\r\nfeedback<\/strong>\u00a0 when one process triggers others which either amplify or mute the original process\r\n\r\nfeldspar<\/strong>\u00a0 a very common framework silicate mineral\r\n\r\nfeldspathic arenite<\/strong>\u00a0 a sandstone consisting predominantly of sand-sized grains and cement (less than 15% fine-grained matrix), and with more than 10% feldspar grains\r\n\r\nfelsic<\/strong>\u00a0 silica rich (>65% SiO2<\/sub>) in the context of magma or igneous rock\r\n\r\nferric<\/strong>\u00a0 the oxidized form of an ion of iron (Fe3+<\/sup>)\r\n\r\nferromagnesian<\/strong> referring to a silicate mineral that contains iron and or magnesium\r\n\r\nferrous<\/strong>\u00a0 the reduced (non-oxidized) form of an ion of iron (Fe2+<\/sup>)\r\n\r\nfetch<\/strong>\u00a0 the distance over which wind blows to form waves\r\n\r\nfinger lake<\/strong>\u00a0 a lake that occupies a glacial valley\r\n\r\nfirn<\/strong>\u00a0 the granular transitional state between snow and ice within a glacier\r\n\r\nflood plain<\/strong>\u00a0 the area that is occupied by water when a stream floods and overtops its banks\r\n\r\nflow<\/strong>\u00a0 a mass-wasting event where material moves which is saturated with water\r\n\r\nflow path<\/strong>\u00a0 the path that groundwater flows along between a recharge area and a discharge area\r\n\r\nflowing artesian well<\/strong>\u00a0 an artesian well in which the water level naturally rises above the surface of the ground\r\n\r\nflux melting<\/strong>\u00a0 melting of rock that is facilitated by the addition of a flux (typically water) which lowers the rock's melting point\r\n\r\nfocus<\/strong> (earthquake)\u00a0 the actual point below surface at which an earthquake takes place (equivalent to hypocentre)\r\n\r\nfoliation<\/strong>\u00a0 the alignment of mineralogical or structural features of a rock \u2013 especially a metamorphic rock\r\n\r\nfootwall<\/strong>\u00a0 the lower surface of a non-vertical fault\r\n\r\nforaminifera<\/strong>\u00a0 single-celled protist with a shell that is typically made of CaCO3<\/sub>fore-reef<\/strong>\u00a0 the zone on the ocean side of a reef\r\n\r\nformation<\/strong>\u00a0 a unit of sedimentary rock that is lithologically consistent and sufficiently thick and extensive to be shown on a geological map at the scale that is typically used in the area in question\r\n\r\nfracking<\/strong>\u00a0 fracturing rock by injecting water and chemicals down a well at very high pressure (equivalent to hydraulic fracturing)\r\n\r\nfractional crystallization<\/strong>\u00a0 the sequential crystallization of minerals from magma, and the physical separation of early-forming crystals from the magma in the area where they crystallized\r\n\r\nfracture<\/strong>\u00a0 a break within a body of rock in which the rock on either side is not displaced\r\n\r\nfringing reef<\/strong>\u00a0 a reef adjacent to a shoreline where there is either a very narrow back reef area or none at all (in which case the reef is effectively attached to the shore)\r\n\r\nfrost line<\/strong> (also, snow line)\u00a0 in the context of newly forming planetary systems, the distance beyond a star at which volatile components (e.g., water, carbon dioxide, methane, ammonia etc.) are frozen\r\n\r\nfrost wedging<\/strong> physical weathering caused when the expansion of freezing water pries rock apart\r\n

<\/a>G<\/h2>\r\nGa<\/strong>\u00a0 (giga annum) billions of years before the present\r\n\r\ngabbro<\/strong>\u00a0 a mafic intrusive igneous rock\r\n\r\nGaia hypothesis<\/strong>\u00a0 the hypothesis advanced by James Lovelock that the organisms have affected the atmosphere and oceans such that conditions on Earth have been kept habitable, in spite of significantly changing energy received from the Sun\r\n\r\ngalaxy<\/strong>\u00a0 gravitationally-bound system of stars and interstellar matter\r\n\r\ngas giant<\/strong>\u00a0 a large planet composed mostly of hydrogen and helium (e.g. Jupiter)\r\n\r\nGeological time (deep time).<\/strong> The long timescales (millions to billions of years) over which geologic processes happen.<\/span>\r\n\r\nGeology. <\/strong>The study of Earth, its materials, and the natural processes acting on and within it.<\/span>\r\n\r\ngeosyncline<\/strong>\u00a0 kilometres thick deposit of sediments that has accumulated along the edge of a continent and is sufficient mass to depress the crust beneath it\r\n\r\ngeothermal gradient<\/strong>\u00a0 the rate of increase of temperature with depth in the Earth (typically around 30\u02daC\/km within the crust)\r\n\r\ngiant impact hypothesis<\/strong>\u00a0 the theory that the Moon formed when a Mars-sized planet (Theia) collided with the Earth at 4.5 Ga\r\n\r\nglacial period<\/strong>\u00a0 a period of Earth\u2019s history during which glacial ice was present over a sufficient extent to have left recognizable evidence\r\n\r\nglacial groove<\/strong>\u00a0 a straight line created on a rock surface by erosion by a rock fragment embedded in the base of glacial ice (larger and deeper than a glacial striation)\r\n\r\nglacial striation<\/strong>\u00a0 a straight line created on a rock surface by erosion by a rock fragment embedded in the base of glacial ice (finer than a glacial groove \u2013 typically less than 1 cm wide)\r\n\r\nglacier<\/strong>\u00a0 a long lasting (centuries or more) body of ice on land that moves under its own weight\r\n\r\nglaciofluvial<\/strong>\u00a0 referring to sediments deposited from a stream that is derived from a glacier\r\n\r\nglaciolacustrine<\/strong>\u00a0 referring to sediments deposited within a lake in a glacial environment\r\n\r\nglaciomarine<\/strong> \u00a0 referring to sediments deposited within the ocean in a glacial environment\r\n\r\nglaucophane<\/strong>\u00a0 a blue sodium-magnesium-bearing amphibole mineral that forms during metamorphism at high pressures and relatively low pressures, typically within a subduction zone\r\n\r\ngneiss<\/strong>\u00a0 high-grade foliated metamorphic rock in which the mineral components are separated into bands of different composition\r\n\r\ngraben<\/strong> a down-dropped fault block, bounded on either side by normal faults\r\n\r\ngrade<\/strong>\u00a0 1. (mineral deposit) the amount of a specific metal or mineral expressed as a proportion of the whole rock. 2. (coal) the extent to which carbon has been concentrated within the coal, and the possible energy output on combustion has increased\r\n\r\ngraded bedding<\/strong>\u00a0 an individual sedimentary layer that shows a distinctive gradation in grain size (normal graded bedding is finer towards the top, reverse graded bedding is coarser towards the top)\r\n\r\ngradient<\/strong>\u00a0 the slope of a stream bed over a specific distance, typically expressed in m per km\r\n\r\ngrain size<\/strong>\u00a0 the diameter of a fragment (clast) of sediment\r\n\r\ngranite<\/strong>\u00a0 a felsic intrusive igneous rock\r\n\r\ngranule<\/strong>\u00a0 a sedimentary particle ranging in size from 2 to 4 mm in diameter\r\n\r\ngreenhouse gas\u00a0<\/strong> a gaseous molecule with 3 or more atoms that is able to absorb infrared radiation\r\n\r\ngreenhouse effect<\/strong> (climate) the ability of an atmosphere to absorb infrared radiation due to the presence of greenhouse gases\r\n\r\ngreenschist<\/strong>\u00a0 1. (metamorphic rock) a foliated metamorphosed rock (typically derived from basalt) in which the green colouration is derived from either chlorite, epidote, or green amphibole. 2. (metamorphic facies) low-grade metamorphic facies characteristic of regional metamorphism\r\n\r\ngreenstone<\/strong>\u00a0 a non-foliated metamorphosed rock (typically derived from basalt) in which the green colouration is derived from either chlorite, epidote or green amphibole. Can be formed by hydrothermal metamorphism on the ocean floor.\r\n\r\ngreywacke<\/strong>\u00a0 a sandstone with more than 15% silt and clay, and with a significant proportion of sand-sized rock fragments\r\n\r\ngroundwater<\/strong>\u00a0 water that lies beneath the surface of the ground\r\n\r\ngroup<\/strong>\u00a0 a stratigraphically continuous series of related formations\r\n\r\ngroyne<\/strong>\u00a0 a man-made structure extending from the shore built to deflect the energy of waves\r\n\r\ngyre<\/strong>\u00a0 a closed circular ocean current\r\n

<\/a>H<\/h2>\r\nhabit<\/strong>\u00a0 a characteristic crystal form or combination of forms of a mineral\r\n\r\nhabitable zone<\/strong>\u00a0 the region around a star that is considered to be suitable for a life-bearing planet\r\n\r\nHadean<\/strong>\u00a0 the first eon of Earth history, extending from 4.57 to 3.80 Ga\r\n\r\nhalide<\/strong>\u00a0 a mineral in which the anion is one of the halide elements (e.g., halite \u2013 NaCl or fluorite - CaF2<\/sub>)\r\n\r\nhalite<\/strong>\u00a0 NaCl, a halide mineral which consititutes table salt\r\n\r\nhalogen<\/strong> an element in the second-last column of the periodic table that forms anions with a negative-1 charge\r\n\r\nhanging valley<\/strong>\u00a0 a glacial valley created by a tributary glacier which does not erode as deeply as the main-valley glacier that it joins\r\n\r\nhanging wall<\/strong>\u00a0 the upper surface of a non-vertical fault\r\n\r\nheadland<\/strong>\u00a0 a point extending out to sea\r\n\r\nhorn<\/strong>\u00a0 a peak that has been eroded on at least three sides by glaciers\r\n\r\nhornfels<\/strong>\u00a0 a fine-grained metamorphic rock that is not foliated. It can have a variety of parent rocks.\r\n\r\nhorst<\/strong>\u00a0 an uplifted fault block, bounded on either side by normal faults\r\n\r\nhot spot<\/strong>\u00a0 the surface area of volcanism and high heat flow above a mantle plume\r\n\r\nhydrated mineral<\/strong>\u00a0 a mineral that includes either hydroxyl (OH) or water (H2<\/sub>O) in its chemical formula (e.g., gypsum CaSO4<\/sub>.2H2<\/sub>O)\r\n\r\nhydraulic conductivity<\/strong>\u00a0 an expression of the rate at which a liquid will flow through a porous medium, as determined by the permeability of the medium and the viscosity of the liquid\r\n\r\nhydraulic fracturing<\/strong>\u00a0 fracturing rock by injecting water and chemicals down a well at very high pressure (equivalent to fracking)\r\n\r\nhydrolysis<\/strong>\u00a0 a reaction between a mineral and water in which H+ ions are added to the mineral and a chemically equivalent amount of cations are released into solution\r\n\r\nhydrothermal\u00a0 <\/strong>refers to hot water solutions and processes involving hot water solutions\r\n\r\nhydrothermal alteration<\/strong>\u00a0 chemical alteration of minerals by hot water solutions\r\n\r\nhydroxide<\/strong>\u00a0 the anion OH-<\/sup> or an mineral that includes that anion\r\n\r\nhypocentre<\/strong>\u00a0 the actual point below surface at which an earthquake takes place (equivalent to focus)\r\n\r\nHypothesis.<\/strong> An informed speculation about how the world works. Scientific hypotheses must be testable.<\/span>\r\n

<\/a>I<\/h2>\r\nice giant<\/strong>\u00a0 a planet that is comprised mainly of gases heavier than hydrogen and helium, including oxygen,\u00a0carbon,\u00a0nitrogen, and\u00a0sulfur (e.g., Uranus and Neptune)\r\n\r\nigneous<\/strong>\u00a0 a rock formed from the cooling of magma\r\n\r\nillite<\/strong>\u00a0 a clay mineral with a composition similar to that of muscovite mica\r\n\r\nimbricate<\/strong>\u00a0 aligned and overlapping, like the tiles on a roof\r\n\r\nindex fossil<\/strong>\u00a0 a fossil with a distinctive appearance and a wide geographic range but from a relatively restricted time range, thus making it useful for dating a correlating rocks from different regions (the most useful index fossils are from organisms that lived for less than a million years)\r\n\r\nindex mineral\u00a0 <\/strong>(metamorphic rocks) a mineral with a stability range of pressures and temperatures sufficiently narrow so as to be useful in indicating the pressures and temperatures at which a metamorphic rock formed.\r\n\r\ninert<\/strong>\u00a0 in chemistry, an element that does not readily react with other elements (e.g., neon)\r\n\r\ninfiltration<\/strong>\u00a0 the recharge of groundwater from the downward percolation of surface water\r\n\r\ninsolation<\/strong>\u00a0 a measure of the intensity of solar energy at a specific location or time (expressed in W\/m2)\r\n\r\nintensity<\/strong>\u00a0 in seismology, a qualitative measure of the amount of shaking at specific location, based on what was felt by observers, or the amount of damage done\r\n\r\nIntergovernmental Panel on Climate Change<\/strong>\u00a0 (IPCC) an international body established in 1988 by the UN\u2019s World Meteorological Organization and the UN Environment Program to prepare periodic reports on the status of global climate change and its mitigation\r\n\r\nintrusive<\/strong>\u00a0 an igneous rock (pluton) that has cooled slowly beneath the surface\r\n\r\nionic bond<\/strong>\u00a0 a bond in which electrons are transferred from one atom to another, thus forming ions\r\n\r\nion<\/strong>\u00a0 an atom that has either gained or lost electrons and has thus become charged (or a group of atoms that also has a charge \u2013 e.g., HCO3<\/sub>-<\/sup>)\r\n\r\nisoclinal fold<\/strong>\u00a0 a tight fold in which the limbs are parallel to each other\r\n\r\nisostasy<\/strong>\u00a0 the equilibrium between a block of crust floating on the underlying plastic mantle\r\n\r\nisostatic sea-level change<\/strong>\u00a0 the effect on relative sea level of a vertical adjustment of the crust resulting from a change in the mass of the crust (e.g., from losing or gaining ice)\r\n\r\nisotherm<\/strong>\u00a0 a surface or line drawn to represent points at the same temperature. (iso<\/em> = same)\r\n\r\nisotope<\/strong> a form of an element that differs from other forms because it has a different number of neutrons (e.g., 16<\/sup>O has 8 protons and 8 neutrons while 18<\/sup>O has 8 protons and 10 neutrons)\r\n

<\/a>J<\/h2>\r\njoint<\/strong>\u00a0 a fracture in rock where the rock on one side has not moved relative to the other side\r\n\r\njointing<\/strong>\u00a0 the formation of joints\r\n\r\nJovian planet<\/strong>\u00a0 a gas giant planet\r\n

<\/a>K<\/h2>\r\nka<\/strong> (kilo annum) thousands of years before the present\r\n\r\nkaolinite<\/strong>\u00a0 a clay mineral that does not have cations other than Al and Si\r\n\r\nkarst<\/strong>\u00a0 the solutional erosion of an area with soluble rock (typically limestone) to form depressions and caves\r\n\r\nkettle<\/strong>\u00a0 a depression formed at the front of a large glacier when a stranded ice block that was surrounded by sediment eventually melts\r\n\r\nkettle lake<\/strong>\u00a0 a lake that forms within a kettle\r\n\r\nkimberlite<\/strong>\u00a0 an ultramafic volcanic rock that originates at significant depth (> 200 m) in the mantle (some kimberlites include diamonds)\r\n\r\nKuiper belt<\/strong>\u00a0 a region of the Solar System beyond the orbit of Neptune that is populated by small objects and dwarf planets (including Pluto)\r\n

<\/a>L<\/h2>\r\nlaccolith<\/strong>\u00a0 concordant intrusion in which the central part has bulged upward\r\n\r\nlahar<\/strong>\u00a0 a mudflow or debris flow that is either caused by a volcanic eruption, or forms on the flank of a volcano as a result of flooding not related to an eruption\r\n\r\nlandfill gas<\/strong>\u00a0 gases produced within a landfill during the microbial breakdown of landfill components (most are dominated by carbon dioxide and methane)\r\n\r\nlarge igneous province (LIP)<\/strong>\u00a0 a very large area of mafic volcanic rock produced by a massive eruption typically related to a mantle plume\r\n\r\nlateral moraine<\/strong>\u00a0 a deposit of rocky material that forms along the margin of a valley or alpine glacier, mostly from the freeze-thaw release of material from the steep slopes above\r\n\r\nlattice<\/strong>\u00a0 the regular and repeating three-dimensional structure of a mineral\r\n\r\nLaurentide Ice Sheet<\/strong>\u00a0 the continental glacier that extended across central eastern North America during the Pleistocene, covering most of Canada and a significant part of the United States\r\n\r\nlava<\/strong>\u00a0 molten rock on Earth's surface (cf. magma)\r\n\r\nlava lev\u00e9e<\/strong>\u00a0 a ridge that forms along the edge of a lava flow because the magma at the edge cools faster than that in the middle\r\n\r\nlava tube<\/strong>\u00a0 a tube that forms as mafic lava flows along a channel and lava leve\u00e9s build up on either side, eventually forming a roof (once a lava tube forms it insulates the flowing magma, allowing it to stay hot a liquid for longer and therefore flow much further)\r\n\r\nLaw.<\/strong> A description that always applies to a scientific phenomenon, given specific conditions.<\/span>\r\n\r\nleachate<\/strong>\u00a0 in the context of landfills, the liquid (rainwater) that passes through the waste and becomes contaminated with soluble components from the waste\r\n\r\nlev\u00e9e<\/strong>\u00a0 on a stream, the ridge that naturally forms along the edge of the channel during flood events\r\n\r\nlevel<\/strong>\u00a0 in mining, a horizontal mine opening\r\n\r\nlight year<\/strong>\u00a0 the distance that light can travel in one year (9.4607 x 1012<\/sup> km)\r\n\r\nlignite<\/strong>\u00a0 a low-grade type of coal with less than 70% carbon\r\n\r\nlimbs<\/strong>\u00a0 the layers of rock on either side of a fold\r\n\r\nlimestone<\/strong>\u00a0 a biochemical sedimentary rock that is comprised mostly of calcite\r\n\r\nliquefaction<\/strong>\u00a0 the tendency for unconsolidated and water saturated sediments to lose strength during seismic shaking\r\n\r\nlithic arenite<\/strong>\u00a0 an arenite in which there is more than 10% lithic clasts and in which there are more lithic clasts than feldspar clasts (see also arenite<\/em>)\r\n\r\nlithic clasts<\/strong>\u00a0 fragments of another rock which are included in the sand-sized grains in sandstone, or in the larger grains in conglomerate\r\n\r\nlithification<\/strong>\u00a0 the conversion of unconsolidated sediments into rock by compaction and cementation\r\n\r\nlithosphere<\/strong>\u00a0 the rigid outer part of the Earth, including the crust and the mantle down to a depth of about 100 km\r\n\r\nlithostatic pressure<\/strong>\u00a0 pressure due to the weight of overlying rocks\r\n\r\nlodgement till<\/strong>\u00a0 sediment that accumulates at the base of a glacier and typically has a wide range of grain sizes (including clay) and is well compacted\r\n\r\nlong axis<\/strong>\u00a0 in a crystal, clast, or grain, the direction in which the length would be the greatest\r\n\r\nlongshore current<\/strong>\u00a0 the movement of water along a shoreline produced by the approach of waves at an angle to the shore\r\n\r\nlongshore drift<\/strong>\u00a0 the movement of sediment along a shoreline resulting from a longshore current and also from the swash and backwash on a beach face\r\n\r\nLove wave<\/strong>\u00a0 a surface seismic wave, with horizontal motion, that develops in relatively weak (e.g., unconsolidated) materials at surface\r\n\r\nluvisol<\/strong>\u00a0 a cold climate forest soil formed in which clay has been removed from the A horizon and relocated into the B horizon\r\n

<\/a>M<\/h2>\r\nMa<\/strong> (Mega annum) millions of years before the present\r\n\r\nmafic<\/strong>\u00a0 silica poor (<45% SiO2) in the context of magma or igneous rock, and containing ferromagnesian minerals such as olivine and pyroxene)\r\n\r\nmagma<\/strong>\u00a0 molten rock within Earth's interior (cf. lava<\/em>)\r\n\r\nmagnetic chronology<\/strong>\u00a0 the study of the timing of reversals of the Earth\u2019s magnetic field, and the application of that understanding to dating geological materials\r\n\r\nmagnitude<\/strong>\u00a0 a measure of the amount of energy released by an earthquake\r\n\r\nmantle<\/strong>\u00a0 the middle layer of the Earth, dominated by iron and magnesium rich silicate minerals and extending for about 2900 km from the base of the crust to the top of the core\r\n\r\nmantle plume<\/strong>\u00a0 a plume of hot rock (not magma) that rises through the mantle (either from the base or from part way up) and reaches the surface where it spreads out and also leads to hot-spot volcanism\r\n\r\nmarble<\/strong>\u00a0 a non-foliated metamorphic rock derived from a limestone or dolostone protolith, in which the calcite or dolomite has been recrystallized into larger crystals\r\n\r\nmass wasting<\/strong>\u00a0 the mass failure, by gravity, of rock or unconsolidated material on a slope\r\n\r\nmatrix<\/strong>\u00a0 finer-grained material between larger clasts within a sedimentary rock\r\n\r\nmaturity<\/strong>\u00a0 the degree to which a sediment or sedimentary rock exhibits characteristics of prolonged physical and chemical weathering and transpor,t\r\n\r\nmeander cutoff<\/strong>\u00a0 the formation of a shorter stream channel across the narrow boundary between two meanders on a stream\r\n\r\nmeandering<\/strong>\u00a0 the sinuous path taken by a stream within a wide flat flood plain\r\n\r\nmechanical weathering<\/strong> (also, physical weathering)\u00a0 weathering that occurs when physical processes cause a rock to break into smaller pieces without changing the chemical composition\r\n\r\nmedial moraine<\/strong>\u00a0 a lateral moraine that has been shifted towards the centre of a valley glacier at a point where two glaciers meet\r\n\r\nmember<\/strong>\u00a0 a subdivision of a formation\r\n\r\nmesopelagic zone<\/strong>\u00a0 the upper middle zone of the open ocean extending from 200 to 1000 m depth\r\n\r\nmetallic lustre<\/strong>\u00a0 the lustre of a mineral into which light does not penetrate but reflects off of the surface without being scattered (i.e., shines reflects light like a shiny metal)\r\n\r\nmetallic bond<\/strong>\u00a0 a type of bond in which abundant electrons are easily shared amongst cations\r\n\r\nmetamorphic facies<\/strong>\u00a0 a group of metamorphic rocks formed under the same range of pressures and temperature conditions, but from different parent rocks\r\n\r\nmetamorphic grade<\/strong>\u00a0 refers to the intensity of metamorphism, and increases as pressure and temperature increase\r\n\r\nmetamorphism<\/strong>\u00a0 the transformation of a parent rock into a new rock as a result of heat and pressure that leads to the formation of new minerals, or recrystallization of existing minerals, without melting\r\n\r\nmetasomatism<\/strong>\u00a0 metamorphism facilitated by ion transfer through water, and which results in a substantial change in the chemical composition (not just the mineral content) of a rock\r\n\r\nmeteoroid<\/strong>\u00a0 a small fragment of stony or metallic debris in space\r\n\r\nmethane hydrate<\/strong>\u00a0 a combination of water ice and methane in which the methane is trapped inside \u201ccages\u201d in the ice\r\n\r\nmica<\/strong>\u00a0 a sheet-silicate mineral (e.g., biotite, muscovite)\r\n\r\nmigmatite<\/strong>\u00a0\u00a0 rock that is part metamorphic and part igneous, formed at\u00a0 very high grades of metamorphism when a part of the parent rock starts to melt\r\n\r\nMilankovitch cycles<\/strong>\u00a0 millennial-scale variations in the orbital and rotational parameters of the Earth that have subtle effects on the Earth\u2019s climate\r\n\r\nMohorovi\u010di\u0107 discontinuity<\/strong> (Moho) the boundary between the crust and the mantle\r\n\r\nmoment magnitude<\/strong>\u00a0 a way of estimating earthquake magnitude based on the area of the rupture surface and the amount of displacement\r\n\r\nmonogenetic<\/strong>\u00a0 a volcano that forms in a single eruptive event\r\n\r\nmoraine lake<\/strong>\u00a0 a finger lake that forms within a glacial valley and is dammed by an end moraine\r\n\r\nmud crack<\/strong>\u00a0 a dessication crack formed when mud shrinks as it dries\r\n\r\nmudflow<\/strong>\u00a0 a mass-wasting event involving the flow of mud (sand, silt and clay) within a channel\r\n\r\nmudrock<\/strong>\u00a0 an inclusive term for mudstone, shale and claystone\r\n\r\nmudstone<\/strong>\u00a0 a fine-grained clastic sedimentary rock with a mixture of silt-sized and clay-sized particles\r\n\r\nmuscovite<\/strong>\u00a0 a potassium-bearing non-ferromagnesian mica\r\n

<\/a>N<\/h2>\r\nnative element<\/strong> (also, native element mineral) a mineral that consists of only one element (e.g., native gold)\r\n\r\nnebula<\/strong>\u00a0 a large cloud of dust and gas in space, frequently hosting the formation of stars\r\n\r\nnegative feedback<\/strong>\u00a0 a process that results in a decrease in that process (in the context of climate change it is a process that reduces the change in climate, such as the enhanced growth of vegetation in response to an increase in atmospheric carbon dioxide)\r\n\r\nneutron<\/strong>\u00a0 a sub-atomic particle with a mass of 1 and a charge of 0\r\n\r\nnonconformity<\/strong>\u00a0 a geological boundary where non-sedimentary rock is overlain by sedimentary rock\r\n\r\nnon-ferromagnesian mineral<\/strong>\u00a0 a silicate mineral that does not contain iron or magnesium (e.g., feldsspar)\r\n\r\nnon-metallic lustre\u00a0 <\/strong>the lustre of a mineral into which light does penetrate, or which does not produce a bright reflection\r\n\r\nnormal fault<\/strong>\u00a0 a non-vertical fault along which the hanging wall (upper surface) has moved down relative to the footwall\r\n\r\nnormal force<\/strong>\u00a0 the component of the gravitational force that acts directly into the slope\r\n\r\nNorth Atlantic Deep Water<\/strong>\u00a0 deep Atlantic Ocean water that has descended in the far north of the basin in the area between Scandinavia and Greenland\r\n\r\nnunatuk<\/strong>\u00a0 a rocky peak that extends above the ice level of a continental glacier\r\n

<\/a>O<\/h2>\r\nobliquity<\/strong>\u00a0 (Milankovitch cycles) the angle of the tilt of the Earth\u2019s rotational axis with respect to the plane of its orbit around the sun\r\n\r\nocean plain<\/strong>\u00a0 the extremely flat surface of the deep ocean floor in areas unaffected by plate tectonic processes and volcanism\r\n\r\noil window<\/strong>\u00a0 the depth range, which is approximately 2000 to 4000 m, within which the temperature is appropriate for the formation of oil from organic matter in sedimentary rock\r\n\r\nooid<\/strong>\u00a0 a small (approximately 1 mm) sphere of calcite formed in areas of tropical shallow marine water with strong currents\r\n\r\nolivine<\/strong> a silicate mineral made up of isolated silica tetrahedra and with either iron or magnesium (or both) as the cations\r\n\r\nOort cloud<\/strong>\u00a0 a spherical cloud of icy objects extending from between about 5,000 and 500,000 astronomical units (Sun-Earth distances) from the Sun (thought to be a source area of comets)\r\n\r\nopen-pit mine<\/strong>\u00a0 a mine that is open to the surface\r\n\r\norganic sedimentary rock\u00a0 <\/strong>a sedimentary rock consisting of materials made of carbon-hydrogen bonds (e.g., animal and plant material)\r\n\r\noutcrop<\/strong>\u00a0 a surface exposure of rock that is part of the crust (bedrock)\r\n\r\noutwash plain<\/strong>\u00a0 an extensive region of sand and gravel deposited by streams flowing out of a glacier (same as sandur)\r\n\r\noverturned\u00a0<\/strong> a geological feature that has been tilted to the point where it is upside down\r\n\r\noxbow<\/strong>\u00a0 a part of a stream meander that has become isolated from the rest of the stream as the result of a meander cutoff\r\n\r\noxidation<\/strong>\u00a0 the reaction between a mineral and oxygen\r\n\r\noxide<\/strong>\u00a0 a mineral in which the anion is oxygen (e.g., hematite Fe2<\/sub>O3<\/sub>)\r\n

<\/a>P<\/h2>\r\npahoehoe<\/strong>\u00a0 a lava flow with a ropy surface texture formed when the surface cools and hardens while the lava beneath is still flowing\r\n\r\npaleomagnetic<\/strong>\u00a0 characterized by past variations in the intensity and polarity of the Earth\u2019s magnetic field\r\n\r\nPangea<\/strong>\u00a0 che supercontinent that existed between approximately 300 and 180 Ma\r\n\r\nparaconformity<\/strong>\u00a0 an interruption representing a period of non-deposition, without tilting or erosion, in a sequence of sedimentary rocks\r\n\r\nparasitic fold<\/strong>\u00a0 a fold within a fold\r\n\r\nparent rock<\/strong> (also, parent material, protolith)\u00a0 the rock that was already in existence when a process of metamorphism started, or the rock from which sediments were derived\r\n\r\npartial melting<\/strong>\u00a0 the process during which a only specific mineral components of a rock melt\r\n\r\nparting<\/strong>\u00a0 a narrow gap between individual sedimentary layers\r\n\r\npassive margin\u00a0<\/strong> a boundary between a continent and an ocean at which there is no tectonic activity (e.g., the eastern edge of North America)\r\n\r\npaternoster lake<\/strong>\u00a0 one of a series of rock basin lakes\r\n\r\npeat<\/strong>\u00a0 a product of the first stage of coal formation, where vegetative material undergoes limited decomposition in a low-oxygen, acidic environment\r\n\r\npebble<\/strong>\u00a0 a sedimentary particle ranging in size from 2 to 64 mm (includes granule)\r\n\r\npelagic<\/strong>\u00a0 the part of a lake or the ocean that is not close to shore\r\n\r\npermafrost<\/strong>\u00a0 ground that remains frozen for two or more years\r\n\r\npermanentism<\/strong>\u00a0 the now discredited theory that the features on the Earth have not changed significantly over geological time\r\n\r\npermeability<\/strong>\u00a0 an expression of the ease with which liquid will flow through a porous medium\r\n\r\nphaneritic<\/strong>\u00a0 a rock texture in which the individual crystals or grains are visible to the naked eye\r\n\r\nPhanerozoic<\/strong>\u00a0 the most resent eon of geological time, encompassing the Paleozoic, Mesozoic and Cenozoic eras\r\n\r\nphenocryst<\/strong>\u00a0 a relatively large crystal within an igneous rock\r\n\r\nphyllosilicate<\/strong>\u00a0 a silicate mineral in which the silica tetrahedra are made up of sheets\r\n\r\nphosphate<\/strong>\u00a0 a mineral in which the anion is PO4<\/sub>3-<\/sup>photic zone<\/strong>\u00a0 the upper 200 m of the ocean or a lake, where, depending on the turbidity of the water, light can penetrate\r\n\r\nphreatic eruption<\/strong>\u00a0 a steam-drive volcanic eruption that takes place when surface or near-surface water is heated by volcanic activity\r\n\r\nphyllite<\/strong>\u00a0 a metamorphic rock with slaty cleavage and a sheen on the surface produced by aligned micas\r\n\r\nphysical weathering\u00a0 <\/strong>(also, mechanical weathering)\u00a0 <\/em>weathering that occurs when physical processes cause a rock to break into smaller pieces without changing the chemical composition\r\n\r\npillow<\/strong>\u00a0 a pillow-shaped mass of volcanic rock (typically basalt) formed when magma erupts beneath the surface\r\n\r\npillow lava<\/strong>\u00a0 a volcanic rock (typically basalt) that is made up primarily of pillows\r\n\r\npipe<\/strong>\u00a0 a cylindrical body of igneous rock. May feed a volcano or connect plutons\r\n\r\nPlate.<\/strong> A fragment of Earth\u2019s surface consisting of lithosphere (crust and uppermost mantle).<\/span>\r\n\r\nPlate tectonics.<\/strong>\u00a0 The concept that the Earth\u2019s crust and upper-most mantle (lithosphere) is divided into a number of plates that move independently on the surface and interact with each other at their boundaries<\/span>\r\n\r\nPlinian eruption<\/strong>\u00a0 a large volcanic eruption in which a column of hot tephra and gases rises many kilometres into the atmosphere\r\n\r\npluton<\/strong>\u00a0 a body of igneous rock formed by cooling within the Earth (i.e., a body of intrusive igneous rock)\r\n\r\npodzol<\/strong>\u00a0 a soil with well-developed horizons formed in temperate forested regions\r\n\r\npodzolization<\/strong>\u00a0 the process of the formation of podsol\r\n\r\npolar wandering path<\/strong>\u00a0 see: apparent polar wandering path\r\n\r\npolymerize<\/strong>\u00a0 the formation of molecular chains within a fluid (e.g., a magma) that lead to an increase in the fluid\u2019s viscosity\r\n\r\npolymorphs<\/strong>\u00a0 two or more minerals with the same chemical formula but different crystal structures\r\n\r\nporosity<\/strong>\u00a0 the percentage of open pore space within a body of rock or sediment\r\n\r\nporphyritic<\/strong>\u00a0 an igneous texture in which some of the crystals are distinctively larger than the rest\r\n\r\nporphyry deposit<\/strong>\u00a0 a mineral deposit (of copper or molybdenum especially) in which part of the host rock is a porphyritic stock\r\n\r\npositive feedback<\/strong>\u00a0 a process that results in an increase in that process (in the context of climate change it is a process that enhances the change in climate, such as the reduced reflectivity of the Earth\u2019s surface when ice melts)\r\n\r\npotassium feldspar<\/strong>\u00a0 feldspar with the formula KAlSi3<\/sub>O8<\/sub>, and which is a common constituent of felsic igneous rocks\r\n\r\npotentiometric surface<\/strong>\u00a0 the imaginary surface defined by the levels to which water would rise in a series of wells drilled into a confined aquifer\r\n\r\nprecession<\/strong> (Milankovitch cycles) the variation in the direction at which the Earth\u2019s rotational axis is pointing\r\n\r\npressure-release cracking<\/strong>\u00a0 cracking of a rock which occurs when overlying rocks are removed by erosion and the outer layer of the rock expands\r\n\r\nprinciple of cross-cutting relationships<\/strong>\u00a0 the principle that a body of rock that cuts across or through another body of rock is younger than that other body\r\n\r\nprinciple of faunal succession<\/strong>\u00a0 the principle that life on Earth has evolved in an orderly way, and that we can expect to always find fossils of a specific type in rocks of a specific age\r\n\r\nprinciple of inclusions<\/strong>\u00a0 the principle that inclusions within a body of rock must be older than the rock\r\n\r\nprinciple of original horizontality<\/strong>\u00a0 the principle that sedimentary beds are originally deposited in horizontal layers\r\n\r\nprinciple of superposition<\/strong>\u00a0 the principle that in a sequence of layered rocks that is not overturned or interrupted by faulting, the oldest will be at the bottom and the youngest at the top\r\n\r\nproglacial<\/strong>\u00a0 referring to the area in front of a glacier\r\n\r\nprotolith\u00a0 <\/strong>(also, parent rock) the rock which was altered to produce a metamorphic rock\r\n\r\nproton<\/strong>\u00a0 a sub-atomic particle with a mass of 1 and a charge of 1\r\n\r\nprotoplanetary disk<\/strong>\u00a0 a rotating cloud of gas and dust surrounding a young star\r\n\r\npumice<\/strong>\u00a0 a highly vesicular (filled with holes left by gas bubbles) felsic volcanic rock (typically composed mostly of glass)\r\n\r\np-wave<\/strong>\u00a0 a seismic body wave that is characterized by deformation of the rock in the same direction that the wave is propagating (compressional vibration)\r\n\r\npyroclastic<\/strong>\u00a0 volcanic material formed during an explosive eruption\r\n\r\npyroclastic density current<\/strong>\u00a0 a body of hot pyroclastic rock and gases that is flowing rapidly down the flank of a volcano\r\n\r\npyroxene<\/strong>\u00a0 a single chain silicate mineral\r\n

<\/a>Q<\/h2>\r\nquartz<\/strong>\u00a0 a silicate mineral with the formula SiO2<\/sub>quartz sandstone<\/strong> (also, quartz arenite) a sandstone in which more than 90% of the grains are quartz\r\n\r\nquartzite<\/strong>\u00a0 a non-foliated metamorphic rock formed from the contact or regional metamorphism of sandstone\r\n

<\/a>R<\/h2>\r\nradial<\/strong> (drainage) a pattern of streams radiating out from a central point, typically an isolated mountain\r\n\r\nradioactivity\u00a0<\/strong> the natural transformation of unstable isotopes into new elements\r\n\r\nradiolaria<\/strong>\u00a0 microscopic (0.1 to 0.2 mm) marine protozoa that produce silica shells\r\n\r\nRayleigh wave<\/strong>\u00a0 a surface seismic wave, with vertical motion\r\n\r\nrecharge<\/strong>\u00a0 the transfer of surface water into the ground to become groundwater\r\n\r\nrecharge area<\/strong>\u00a0 an area of an aquifer where recharge is predominant over discharge\r\n\r\nrecrystallization\u00a0 <\/strong>during metamorphism, mineral crystals dissolving and reforming as larger crystals\r\n\r\nrectangular drainage<\/strong> a pattern in which tributaries typically flow at right angles to each other and meet at right angles\r\n\r\nrecumbent fold<\/strong>\u00a0 a fold that is overturned such that its limbs are close to horizontal\r\n\r\nredshift<\/strong>\u00a0 the increase in wavelength of light resulting from the fact that the source of the light is moving away from the observer\r\n\r\nreef<\/strong>\u00a0 a mound of carbonate formed in shallow tropical marine environments by corals, algae and a wide range of other organisms\r\n\r\nregional<\/strong> metamorphism<\/strong>\u00a0 metamorphism caused by burial of the parent rock to depths greater than 5 km (typically takes place beneath mountain ranges, and extends over areas of hundreds of km2<\/sup>)\r\n\r\nremnant magnetism<\/strong>\u00a0 magnetism of a body of rock that formed at the time the rock formed and is consistent with the magnetic field orientation that existed at that time and place (see also paleomagnetism<\/em>)\r\n\r\nreservoir rock<\/strong>\u00a0 rock into which petroleum has migrated and is now trapped\r\n\r\nresidual soil<\/strong>\u00a0 soil formed by weathering of the underlying rock or sediment\r\n\r\nretrograde metamorphism<\/strong>\u00a0 metamorphism that transforms a higher grade metamorphic rock into a lower grade metamorphic rock\r\n\r\nreverse fault<\/strong>\u00a0 a non-vertical fault along which the hanging wall (upper surface) has moved up relative to the footwall\r\n\r\nrhyolite<\/strong>\u00a0 a felsic volcanic rock\r\n\r\nridge push<\/strong>\u00a0 the concept that at least part of the mechanism of plate motion is the push of oceanic lithosphere down from a ridge area\r\n\r\nrip current<\/strong>\u00a0 a strong flow of water outward from a beach\r\n\r\nripple<\/strong>\u00a0 a series of small parallel ridges formed within sediment that has accumulated in moving water or wind\r\n\r\nrip-rap<\/strong>\u00a0 angular rock fragments, typically boulder sized, used to armour slopes and shorelines against erosion\r\n\r\nroche mouton\u00e9e<\/strong>\u00a0 a product of glaciation in which a bedrock protrusion is eroded into a streamlined shape that has a broken or jagged leading (down-ice) edge\r\n\r\nrock avalanche<\/strong>\u00a0 a rapid turbulent flow of broken bedrock fragments down a steep slope\r\n\r\nrock basin lake<\/strong>\u00a0 a lake situated in a rock basin carved at the upper end of an alpine glacier\r\n\r\nrock cleavage\u00a0 <\/strong>the tendency of a rock to break along planes defined by foliation\r\n\r\nrock cycle<\/strong>\u00a0 the series of processes through which rocks are transformed from one type to another\r\n\r\nrock fall \u00a0<\/strong> the near-vertical fall or bouncing of rock released from a steep slope\r\n\r\nrock slide<\/strong>\u00a0 the translational motion of an essentially intact body of rock down a slope (rock slides are typically slow, because once they start to move fast the rock body becomes fragmented and then flows as a rock avalanche)\r\n\r\nroot wedging<\/strong>\u00a0 a physical weathering process in which roots grow into cracks in rocks and force them open\r\n\r\nrounding<\/strong>\u00a0 describes the extent to which clasts have had their edges and corners smoothed off\r\n\r\nrunoff<\/strong>\u00a0 flow of water down a slope, either across the ground surface, or within a series of channels\r\n\r\nrupture<\/strong>\u00a0 breaking of rock subject to stress, typically resulting in an earthquake\r\n\r\nrupture surface<\/strong>\u00a0 the area over which rock rupture takes place during an earthquake\r\n

<\/a>S<\/h2>\r\nsackung<\/strong>\u00a0 an escarpment or trough at the top of a slow-moving rock slide (sackungen)\r\n\r\nsaltation<\/strong>\u00a0 the bouncing of particles along a stream bottom or desert floor\r\n\r\nsalt wedging<\/strong>\u00a0 a physical weathering process in which water with dissolved salt flows into a crack, and as the water evaporates, salt crystals grow and push the crack open\r\n\r\nsand<\/strong>\u00a0 a mineral or rock fragment ranging in size from 1\/16th to 2 mm\r\n\r\nsandstone<\/strong>\u00a0 a rock that is primarily comprised of sand-sized particles\r\n\r\nsandur<\/strong>\u00a0 an extensive region of sand and gravel deposited by streams flowing out of a glacier (same as outwash plain)\r\n\r\nsaturated zone<\/strong>\u00a0 the part of an aquifer, or any body of rock, that is saturated with water\r\n\r\nschist<\/strong>\u00a0 a foliated metamorphic rock with crystals large enough to be visible to the unaided eye\r\n\r\nScientific method.<\/strong> A way to collect scientific facts in as reliable a way as possible. A hypothesis is formulated and tested. Whether the hypothesis passes or fails the test will determine whether it is kept or discarded.<\/span>\r\n\r\nsea cave<\/strong>\u00a0 a shallow cave formed on a rocky shore by wave erosion\r\n\r\nsea cliff<\/strong>\u00a0 a coastal escarpment that is typically eroding inland as a result of wave action\r\n\r\nsea-floor spreading<\/strong>\u00a0 the formation of new oceanic crust by volcanism at a divergent plate boundary\r\n\r\nsector collapse<\/strong>\u00a0 the sudden collapse of a significant part of the flank of a volcano\r\n\r\nsedimentary rock<\/strong>\u00a0 rock that has formed by the lithification of sediments or by the precipitation of ions from water\r\n\r\nsediments<\/strong>\u00a0 unconsolidated (loose) particles of mineral or rock\r\n\r\nseismic<\/strong>\u00a0 pertaining to earthquakes\r\n\r\nseismic moment<\/strong>\u00a0 a measurement of an earthquake\u2019s energy based on longwave vibrations, or on the product of the fault area and displacement\r\n\r\nseismic reflection sounding<\/strong>\u00a0 measurement of the properties of sediments based on detection of sounds generated at surface and reflected from layers beneath the surface\r\n\r\nseptae<\/strong>\u00a0 calcareous partitions between the successive living chambers in a cephalopod\r\n\r\nseptic system<\/strong>\u00a0 a system constructed to facilitate the dispersion and detoxification of sewage (typically includes a septic tank and a drainage field)\r\n\r\nshaft<\/strong>\u00a0 a vertical opening at a mine\r\n\r\nshale<\/strong>\u00a0 a silt- and clay-rich rock that has evidence of layering\r\n\r\nshatter cone<\/strong>\u00a0 conical nested fractures that result from extraterrestrial impacts. Cones point toward the impact.\r\n\r\nshear force<\/strong>\u00a0 the component of the gravitational force in the direction parallel to a slope\r\n\r\nshear strength<\/strong>\u00a0 the strength of a body of rock or sediment that counteracts the shear force\r\n\r\nshear stress<\/strong>\u00a0 the stress placed on a body of rock or sediment adjacent to a fault\r\n\r\nsheeted dikes<\/strong>\u00a0 a series of near-vertical dykes formed in the vicinity of a spreading ridge when magma from depth flows into fractures formed by extensional forces\r\n\r\nsheet silicate<\/strong>\u00a0 a silicate mineral in which the silica tetrahedra are combined within sheets\r\n\r\nsheetwash<\/strong>\u00a0 overland flow of water, typically related to a heavy precipitation event\r\n\r\nshield\u00a0 <\/strong>a region of ancient (typically Precambrian) crystalline rock (equivalent to a craton)\r\n\r\nshield volcano<\/strong>\u00a0 a low-profile volcano formed primarily from eruptions of low-viscosity mafic magma\r\n\r\nshocked quartz<\/strong>\u00a0 quartz crystals in which the structure has been deformed by sudden, intense pressure. Deformation is visible as parallel lines within the crystal. with damage along parallel plains\r\n\r\nSial (sialic)<\/strong>\u00a0 an outdated term referring to rock or magma in which silica and aluminum are the predominant components (generally equivalent to felsic)\r\n\r\nsilica<\/strong>\u00a0 a form of the mineral quartz (SiO2<\/sub>)\r\n\r\nsilica tetrahedron<\/strong>\u00a0 an ion which is a combination of 1 silicon atom and 4 oxygen atoms that form a tetrahedron shape (SiO4<\/sub>4-<\/sup>)\r\n\r\nsilicate<\/strong>\u00a0 a mineral that includes silica tetrahedra\r\n\r\nsilicon<\/strong>\u00a0 the 14th element\r\n\r\nsilicone<\/strong>\u00a0 resin or caulking made from silicon<\/strong>-oxygen chains and various organic molecules\r\n\r\nsill<\/strong>\u00a0 a tabular igneous intrusion (pluton) that is parallel to existing layering in the country rock\r\n\r\nsilt<\/strong>\u00a0 sedimentary particles ranging is size from 1\/256th to 1\/16th of a mm\r\n\r\nsiltstone<\/strong>\u00a0 a clastic sedimentary rocks consisting predominately of silt-sized particles\r\n\r\nSima (simatic)<\/strong>\u00a0 an outdated term referring to rock or magma in which silica, magnesium and iron are the predominant components (generally equivalent to mafic)\r\n\r\nskarn<\/strong>\u00a0 the contact metamorphism (and metasomatism) of limestone\r\n\r\nslab pull<\/strong>\u00a0 the concept that at least part of the mechanism of plate motion is the pull of oceanic lithosphere down into the mantle\r\n\r\nslate<\/strong>\u00a0 a fine-grained metamorphic rock that splits easily into sheets\r\n\r\nslaty cleavage<\/strong>\u00a0 the tendency for slate or phyllite to split into sheets (note that this is the only situation in this textbook where the term \u201ccleavage\u201d is applied to a rock as opposed to a mineral)\r\n\r\nslide<\/strong>\u00a0 the downward movement of rock or sediment on a slope as an intact mass\r\n\r\nslump<\/strong>\u00a0 a slide in which the nature of the motion is rotational (typically only develops in unconsolidated sediments)\r\n\r\nsmectite<\/strong>\u00a0 a fine-grained sheet silicate mineral that can accept water molecules into interlayer spaces, resulting is swelling\r\n\r\nsmelter<\/strong>\u00a0 a refinery at which minerals are processed to produce pure metals\r\n\r\nsnow line<\/strong> (frost line)\u00a0 in the context of newly forming planetary systems, the distance beyond a star at which volatile components (e.g., water, carbon dioxide, methane, ammonia etc.) are frozen\r\n\r\nsoil horizon<\/strong>\u00a0 a layer, within a well-developed soil, that is physically or chemically different from layers above or below\r\n\r\nsolar system<\/strong>\u00a0 a star and the planets surrounding it. Sometimes used specifically for the sun and its planets, and planetary system used for other stars\r\n\r\nsolar wind<\/strong>\u00a0 a stream of ionized (charged) particles away from the sun\r\n\r\nsolid solution<\/strong>\u00a0 the substitution of one element for another in a mineral (e.g., in Bowen's reaction series there exists a continuum of plagioclase feldspar where calcium becomes progressively less common, and sodium more so)\r\n\r\nsolifluction<\/strong>\u00a0 the flow of water saturated sediment or soil over a stronger and less permeable substrate\r\n\r\nsorting<\/strong>\u00a0 the extent to which the grain size within a sample of sediment is similar.\u00a0 Well-sorted sediments have very similar grain sizes, and poorly-sorted sediments have a variety of grain sizes.\r\n\r\nsource rock<\/strong>\u00a0 the sedimentary rock from which petroleum originates prior to its migration into a reservoir rock\r\n\r\nspeleothem<\/strong>\u00a0 a cave structure formed when calcium carbonate precipitates (see also stalactite, stalagmite)\r\n\r\nsphericity<\/strong>\u00a0 the extent to which a grain is the same diameter in all dimensions (e.g., more like a sphere, but without implying roundness or smoothness)\r\n\r\nspit<\/strong>\u00a0 a sand or coarser deposit extending from shore out into open water\r\n\r\nspring<\/strong>\u00a0 a flow of groundwater onto the surface\r\n\r\nstack<\/strong>\u00a0 a prominent rocky island that is a remnant of the erosion of a headland\r\n\r\nstage<\/strong>\u00a0 the level of water in a stream\r\n\r\nstalactite<\/strong>\u00a0 a cone-shaped speleothem that is suspended from the roof of a cave\r\n\r\nstalagmite<\/strong>\u00a0 a cone-shaped speleothem that forms on the floor of a cave\r\n\r\nstep-pool<\/strong>\u00a0 a characteristic of stream flow in which water flows from one pool to another, typically on a stream with a steep gradient\r\n\r\nstock<\/strong>\u00a0 an irregular pluton with n exposed area less than 100 km2<\/sup>stoping<\/strong>\u00a0 the fracturing and incorporation of fragments of country rock as a magma body moves upward through the crust\r\n\r\nstrain<\/strong>\u00a0 the deformation of rock that is subjected to stress\r\n\r\nstreak<\/strong>\u00a0 the mark left on a porcelain plate when a mineral sample is ground to a powder by being rubbed across the plate (typically provides a more reliable depiction of the colour than the whole sample)\r\n\r\nstream<\/strong>\u00a0 any body of flowing water\r\n\r\nstress<\/strong> a force applied to a rock (specifically, the force per unit area)\r\n\r\nstress transfer<\/strong> the change in the pattern of stress on a region of rock as a result of an earthquake (typically stress is reduced in the area of a rupture zone, but is increased elsewhere in the vicinity)\r\n\r\nstrike<\/strong>\u00a0 the compass direction of a horizontal line on a sloped surface (e.g., bedding plane, fracture etc.)\r\n\r\nstrike-slip fault<\/strong>\u00a0 a fault that is characterized by motion that is close to horizontal and parallel to the strike direction of the fault\r\n\r\nsubaerial eruption<\/strong>\u00a0 a volcanic eruption that takes place on land\r\n\r\nsubaqueous eruption<\/strong>\u00a0 a volcanic eruption that takes place under water\r\n\r\nsubducted<\/strong>\u00a0 when part of a plate is forced beneath another plate along a subduction zone\r\n\r\nsubduction zone<\/strong>\u00a0 the sloping region along which a tectonic plate descends into the mantle beneath another plate\r\n\r\nsubglacial<\/strong>\u00a0 beneath a glacier\r\n\r\nsulphate<\/strong>\u00a0 a mineral in which the anion is SO4<\/sub>2-<\/sup>sulphide<\/strong>\u00a0 a mineral in which the anion is S2-<\/sup>supergroup<\/strong>\u00a0\u00a0 a stratigraphically continuous series of related groups\r\n\r\nsuperterrane<\/strong>\u00a0 a number of terranes that are contiguous\r\n\r\nsupraglacial<\/strong>\u00a0 on the surface of a glacier\r\n\r\nsurf zone\u00a0<\/strong> the near-shore zone where waves are breaking into surf\r\n\r\nsuture<\/strong>\u00a0 the line on the surface of a cephalopod that marks the boundary between a septum and the outer shell\r\n\r\nswash<\/strong>\u00a0 the upward motion of a wave on a beach (typically takes place at the same angle that the waves are approaching the shore)\r\n\r\ns-wave<\/strong>\u00a0 a seismic body wave that is characterized by deformation of the rock transverse to the direction that the wave is propagating\r\n\r\nsymmetrical<\/strong> a fold in which the limbs are at the same angle to the hinge\r\n\r\nsyncline<\/strong> a downward fold where the beds are known not to be overturned\r\n\r\nsynform<\/strong>\u00a0 a downward fold where it is not known if the beds are overturned\r\n

<\/a>T<\/h2>\r\ntabular<\/strong>\u00a0 referring to a structure that is sheet-like (or like a table top). See also dike, sill\r\n\r\ntailings<\/strong>\u00a0 the fine-grained waste rock from a plant used to concentrate ore minerals\r\n\r\ntalus slope\u00a0 <\/strong>a sloped deposit of angular rock fragments at the base of a rocky escarpment\r\n\r\ntarn<\/strong>\u00a0 a lake within a rock basin\r\n\r\ntectonic plate<\/strong>\u00a0 a fragment of the lithosphere that moves across the surface of the Earth as a single unit\r\n\r\ntectonic sea level change<\/strong>\u00a0 relative sea level change related to the vertical motion of a crustal block caused by tectonic processes\r\n\r\ntephra<\/strong>\u00a0 fragments of volcanic rock (including volcanic ash) ejected during an explosive eruption\r\n\r\nterminal moraine<\/strong>\u00a0 and end moraine that marks the farthest forward advance of a glacier\r\n\r\nterrane<\/strong>\u00a0 a block of crust that has geological features which are distinctive from neighbouring regions, and is assumed to have been moved from elsewhere by tectonic processes\r\n\r\nterrestrial planet\u00a0 <\/strong>a planet with a rocky mantle and crust, and metallic core (e.g., Earth)\r\n\r\nterrigenous\u00a0<\/strong> referring to sedimentary particles that originated on a continent\r\n\r\ntest\u00a0 <\/strong>the shell-like hard parts (either silica or carbonate) of small organisms such as radiolarian and foraminifera\r\n\r\nTheory.<\/strong> A hypothesis that has passed repeated and rigorous testing.<\/span>\r\n\r\nthrust fault\u00a0<\/strong> a low angle reverse fault\r\n\r\ntill<\/strong>\u00a0 unsorted sediment transported and deposited by glacial ice\r\n\r\ntiltmete<\/strong>r\u00a0 a sensitive instrument used to monitor subtle changes in the tilt of the land, particularly in studies of active volcanoes\r\n\r\ntombolo<\/strong>\u00a0 a sand or coarser deposit connecting an island or rocky prominence to a larger body of land\r\n\r\ntraction<\/strong>\u00a0 a force that contributes to the movement of particles situated on a stream bed or desert floor\r\n\r\ntransform fault<\/strong>\u00a0 a boundary between two plates that are moving horizontally with respect to each other\r\n\r\ntransportation\u00a0 r<\/strong>efers to moving sediments from one location to another\r\n\r\ntransported soils<\/strong>\u00a0 soils which form on sediments that have been moved from their original location.\u00a0 The soils themselves have not been transported.\r\n\r\ntravertine<\/strong>\u00a0 a deposit of calcium carbonate that forms at springs, hot springs or within limestone caves\r\n\r\ntrellis<\/strong>\u00a0 a drainage pattern in which tributaries typically flow parallel to one other but meet at right angles\r\n\r\ntrigger<\/strong>\u00a0 an event, such as an earthquake or a heavy rainfall, that starts a mass wasting event\r\n\r\ntrough<\/strong>\u00a0 the lowest point of a wave\r\n\r\ntruncated spur<\/strong>\u00a0 the steep end of a ridge or ar\u00eate that has been eroded by a main-valley glacier\r\n\r\ntsunami<\/strong>\u00a0 a long-wavelength wave produced by the vertical motion of the floor of the ocean or a large lake, typically related either to an earthquake or a sub-marine mass wasting event\r\n\r\ntufa<\/strong>\u00a0 a form of travertine that is especially porous as it forms around existing vegetative material.\r\n\r\ntuya<\/strong>\u00a0 a flat-topped volcanic hill or mountain that formed when an eruption took place beneath a glacier and the melting led to the formation of a lake that then resulted in the wave-erosion of the top of the volcano\r\n

<\/a>U<\/h2>\r\nunconfined aquifer<\/strong>\u00a0 an aquifer that is not overlain by a confining layer\r\n\r\nunconformity<\/strong>\u00a0 a geological boundary at the base of a sedimentary layer\r\n\r\nunconformity-type uranium deposit<\/strong>\u00a0 a uranium deposit that has formed at a nonconformity between sandstone and older rock\r\n\r\nuncompressed density<\/strong>\u00a0 the density of planetary material that it would have it was not compressed by the planets gravitational force\r\n\r\nunderground storage tank<\/strong> (UST) an underground tank for storing liquids, most commonly for liquid fuel\r\n\r\nUniformitarianism.<\/strong> The idea that geological processes today can be used to understand geological processes in the past.<\/span>\r\n\r\nunsaturated zone<\/strong>\u00a0 the rock or sediment above the water table\r\n\r\nU-shaped valley<\/strong>\u00a0 a relatively straight valley with a flat bottom and steep sides that has been carved by a valley glacier\r\n

<\/a>V<\/h2>\r\nvalley glacier<\/strong>\u00a0 a glacier formed in a mountainous region and confined to a valley (same as alpine glacier)\r\n\r\nvarve<\/strong>\u00a0 a recognizable layer within sediments that represents a single year of deposition\r\n\r\nvesicular<\/strong>\u00a0 an igneous texture characterized by holes left by gas bubbles\r\n\r\nvolcanic glass<\/strong>\u00a0 lava that has cooled within minutes, not allowing time for the formation of crystals\r\n\r\nvolcanic-hosted massive sulphide<\/strong>\u00a0 a mineral deposit hosted by volcanic rocks and including zones where most of the rock is made up of sulphide minerals (including ore minerals and pyrite)\r\n

<\/a>W<\/h2>\r\nwacke<\/strong>\u00a0 a sandstone with more than 15% clay and silt\r\n\r\nwater table<\/strong>\u00a0 the upper surface of the saturated zone in an unconfined aquifer\r\n\r\nwave base<\/strong>\u00a0 the depth of water that is affected by the sub-surface orbital motion of wave action (approximately one-half of the wavelength)\r\n\r\nwave-cut platform<\/strong>\u00a0 a nearly-horizontal bench of rock eroded by waves within the surf zone (equivalent to wave-cut terrace)\r\n\r\nwavelength<\/strong>\u00a0 the distance between the crests of two waves\r\n\r\nweathering<\/strong>\u00a0 a range of processes taking place in the surface environment, through which solid rock is transformed into sediment and ions in solution\r\n\r\nwedging<\/strong>\u00a0 physical (mechanical) weathering processes which involve forcing open cracks in a rock (see also frost wedging, root wedging, salt wedging)\r\n\r\nWestern Canada Sedimentary Basin<\/strong>\u00a0 a large basin in the western interior of Canada, east of the Rocky Mountains, extending from the northern United States to the Northwest Territories\r\n\r\nWisconsin Glaciation<\/strong>\u00a0 the most recent advance of the Pleistocene glaciations, extending from 85 to 11 ka\r\n

<\/a>X<\/h2>\r\nxenolith<\/strong> (zee-know-lith) A fragment of country rock incorporated into igneous rock, commonly as a result of stoping\r\n

<\/a>Y<\/h2>\r\nyouthful stream<\/strong>\u00a0 a stream that is actively down-cutting its valley in an area that has recently been uplifted\r\n

<\/a>Z<\/h2>\r\nzone of ablation<\/strong>\u00a0 the part of a glacier, below the equilibrium line, where there is net loss of ice mass due to melting and calving\r\n\r\nzone of accumulation<\/strong>\u00a0 the part of a glacier, above the equilibrium line, where there is net gain of ice mass because not all of the snow that falls each winter is able to melt during the following summer","rendered":"

A<\/a> B<\/a> C<\/a> D<\/a> E<\/a> F<\/a> G<\/a> H<\/a> I<\/a> J<\/a> K<\/a> L<\/a> M<\/a> N<\/a> O<\/a> P<\/a> Q<\/a> R<\/a> S<\/a> T<\/a> U<\/a> V<\/a> W<\/a> X<\/a> Y<\/a> Z<\/a><\/h1>\n

<\/a>A<\/h2>\n

aa<\/strong>\u00a0 a lava flow that solidifies with a blocky high-relief surface<\/p>\n

ablation<\/strong>\u00a0 melting of ice in the context of glaciation<\/p>\n

ablation till<\/strong>\u00a0 till that is formed when englacial and supraglacial sediments are deposited because the ice that was supporting them melts<\/p>\n

abyssal plain<\/strong>\u00a0 the flat surface of the deep ocean, typically beyond the limits of the continental slopes<\/p>\n

abyssal pelagic zone<\/strong>\u00a0 the deeper parts of the ocean, between 4000 and 6000 m.<\/p>\n

accretion<\/strong> (plate tectonics) the process by which continental blocks (terranes) are added to existing continental areas<\/p>\n

accretion<\/strong> (planetary) the process by which solid celestial bodies are added to existing bodies during collisions<\/p>\n

acid rock drainage<\/strong> (acid mine drainage) the production of acid from oxidation of sulphide minerals (especially pyrite) in either naturally or anthropogenically exposed rock<\/p>\n

aeolian<\/strong>\u00a0 processes related to transportation and deposition of sediments by wind<\/p>\n

aerobic<\/strong> processes that take place in the presence of abundant oxygen<\/p>\n

aerosol<\/strong>\u00a0 an aggregate of fine solid particles or a small droplet of liquid suspended in the air<\/p>\n

aftershock<\/strong> an earthquake that can be shown to have been caused by another earthquake<\/p>\n

aggregate<\/strong> unconsolidated materials (typically sediments) that are used in the construction industry<\/p>\n

albedo<\/strong>\u00a0 the reflectivity of a surface of a planet (expressed as the percentage of light that reflects)<\/p>\n

albite<\/strong>\u00a0 sodium-rich plagioclase feldspar<\/p>\n

alpine glacier<\/strong> a glacier formed in a mountainous region and confined to a valley (same as valley glacier)<\/p>\n

amphibole<\/strong>\u00a0 a double-chain ferromagnesian silicate mineral (e.g., hornblende)<\/p>\n

amphibolite<\/strong> a foliated metamorphic rock in which the mineral amphibole as an important component<\/p>\n

amplification<\/strong>\u00a0 in the context of seismic shaking the process by which the amplitude of the seismic waves are enhanced<\/p>\n

amplitude<\/strong> for any type of wave, the difference in height between a crest and the adjacent trough<\/p>\n

anaerobic<\/strong>\u00a0 processes that take place without oxygen<\/p>\n

andesite<\/strong>\u00a0 a volcanic rock of intermediate composition<\/p>\n

anion<\/strong>\u00a0 a negatively charged ion<\/p>\n

angular unconformity<\/strong>\u00a0 a geological boundary at the base of a sedimentary layer where the sedimentary rock beneath has been tilted or folded and then eroded<\/p>\n

anorthite<\/strong>\u00a0 calcium-rich plagioclase feldspar<\/p>\n

Antarctic Bottom Water<\/strong>\u00a0 water at abyssal depths in the ocean that forms from the sinking of dense cold water adjacent to Antarctica<\/p>\n

anticline<\/strong>\u00a0 an upward fold where the beds are known not to be overturned<\/p>\n

anthracite<\/strong>\u00a0 a high grade of coal (92 to 98% carbon) that is formed from deep burial and weak metamorphism<\/p>\n

anthropogenic<\/strong>\u00a0 resulting from the influence of humans<\/p>\n

antiform<\/strong> an upward fold where it is not known if the beds have been overturned<\/p>\n

apparent polar wandering path<\/strong>\u00a0 a path of seeming varying magnetic pole positions defined by paleomagnetic data, which is in fact an artefact of the motion of contients<\/p>\n

aphanitic<\/strong>\u00a0 an igneous texture characterized by crystals that are too small to see with the naked eye<\/p>\n

aquifer<\/strong> a body of rock or sediment that has sufficient permeability to allow it to be used as a source of groundwater<\/p>\n

aquitard<\/strong>\u00a0 a body of rock or sediment that has insufficient permeability to allow it to be used as a source of groundwater<\/p>\n

arch<\/strong>\u00a0 a rock weathering remnant in the form of an arch (typically along a coast and resulting from wave erosion)<\/p>\n

arenite<\/strong>\u00a0 a sandstone with less than 15% silt and clay<\/p>\n

ar\u00eate<\/strong> \u00a0 a sharp ridge that separates adjacent glacially carved valleys<\/p>\n

arkose<\/strong>\u00a0 a sandstone with more than 10% feldspar and more feldspar than lithic fragments<\/p>\n

arkosic arenite<\/strong>\u00a0 an arkose with less than 15% clay\/silt matrix<\/p>\n

artesian well<\/strong>\u00a0 a well that is completed in a confined aquifer and in which the water level in the well rises above the top of the aquifer<\/p>\n

asteroid<\/strong>\u00a0 a rocky body orbiting the Sun<\/p>\n

asteroid belt<\/strong>\u00a0 the region between the orbits of Mars and Jupiter that is populated with many asteroids<\/p>\n

asthenosphere<\/strong>\u00a0 the part of the mantle, from about 100 to 200 km below surface, within which the mantle material is close to its melting point, and therefore relatively weak<\/p>\n

asymmetrical<\/strong> (folds) where the two sides of the fold make significantly different angles with respect to the axial plane<\/p>\n

atoll<\/strong>\u00a0 a ring-shaped carbonate (or coral) reef or series of islands<\/p>\n

atomic mass<\/strong>\u00a0 the total number of neutrons plus protons in an atom<\/p>\n

atomic number<\/strong>\u00a0 the total number of protons in an atom<\/p>\n

attitude<\/strong>\u00a0 the orientation of a sloping geological feature, such as a bedding plane or fracture<\/p>\n

aureole<\/strong>\u00a0 a zone of metamorphism around a source of heat such as a magma body<\/p>\n

axial plane<\/strong>\u00a0 a plane that can be traced through all of the hinge lines of a fold<\/p>\n

<\/a>B<\/h2>\n

back reef<\/strong>\u00a0 the zone of shallow water on the shore-side of a reef<\/p>\n

background<\/strong> (geochemistry)\u00a0 the typical level of an element in average rocks or sediments<\/p>\n

backwash<\/strong>\u00a0 the wash of wave water down the slope of a beach<\/p>\n

banded iron formation<\/strong>\u00a0 an iron-bearing sedimentary rock that is rich in minerals such as hematite and magnetite, and interbedded with chert stained red by hematite<\/p>\n

bank-full stage<\/strong>\u00a0 the water level of stream when it is in flood and just about to flow over its banks<\/p>\n

barrier reef<\/strong>\u00a0 a carbonate (or coral) reef that forms a barrier to waves along a coast<\/p>\n

basal sliding<\/strong>\u00a0 the motion of glacial ice along the base of a glacier that is warm enough to have liquid water<\/p>\n

basalt<\/strong>\u00a0 a volcanic rock of mafic composition<\/p>\n

base level<\/strong> (stream) the base level is the lowest level that a stream can erode down to, as defined by the ocean, a lake or another stream that it flows into<\/p>\n

batholith<\/strong> an irregular body of intrusive igneous rock that has an exposed surface of at least 100 km2<\/sup>bathypelagic zone<\/strong>\u00a0 the moderately deep parts of the ocean, between 1000 and 4000 m.<\/p>\n

baymouth bar<\/strong> a spit that extends across the mouth of a bay<\/p>\n

beach face<\/strong> the part of the beach that is relatively steep and lies between the high and low tide levels<\/p>\n

bed<\/strong>\u00a0 a sedimentary layer<\/p>\n

bed load<\/strong>\u00a0 the fraction of a stream\u2019s sediment load that typically rests on the bottom and is moved by saltation and traction<\/p>\n

bedding<\/strong> repeated layering in a sedimentary rock<\/p>\n

bentonite<\/strong>\u00a0 a smectite clay that has strong swelling properties and is effective at absorbing dissolved ions<\/p>\n

berm<\/strong>\u00a0 a flat area of a beach in the backshore area (above the high tide level)<\/p>\n

big-bang theory<\/strong> the theory that the universe started by expanding suddenly from a single point approximately 13.77 billion years ago<\/p>\n

biochemical sedimentary rock<\/strong>\u00a0 a rock formed when biological processes cause ions to precipitate (e.g., when organisms make shells of calcite or silica)<\/p>\n

biotite<\/strong>\u00a0 a sheet-silicate mineral (mica) that includes iron and or magnesium, and is therefore a ferromagnesian silicate<\/p>\n

biozone<\/strong>\u00a0 a stratigraphic interval that can be defined on the basis of a specific fossil<\/p>\n

bituminous coal<\/strong>\u00a0 a medium-grade type of coal with 70 to 92% carbon<\/p>\n

blueschist<\/strong>\u00a0 1. (metamorphic rock) a schist with blue colouring due to the presence of the mineral glaucophane. Formed in subduction zones. 2. (metamorphic facies) a facies characterized by relatively low temperatures and high pressures, such as can exist within a subduction zone<\/p>\n

body wave<\/strong>\u00a0 a seismic wave that travels through rock (e.g., a P-wave or an S-wave)<\/p>\n

boulder<\/strong>\u00a0 a sediment clast with a diameter of at least 256 mm<\/p>\n

Bowen’s reaction series<\/strong>\u00a0 the scheme that defines the typical order of crystallization of minerals from magma as the magma cools<\/p>\n

braided<\/strong>\u00a0 a stream pattern which is characterized by abundant sediment and numerous intertwining channels around bars<\/p>\n

breakwater<\/strong> a structure built offshore in order to deflect the energy of waves<\/p>\n

breccia<\/strong>\u00a0 a sedimentary or volcanic rock texture characterized by angular clasts<\/p>\n

brunisol<\/strong>\u00a0 a relatively immature forest soil, lacking in well-defined horizons<\/p>\n

burial<\/strong>\u00a0 when a layer of sediment is covered by subsequent sediment accumulation<\/p>\n

<\/a>C<\/h2>\n

caldera<\/strong>\u00a0 a volcanic depression that forms when part of the volcano collapses into an empty magma chamber<\/p>\n

caliche<\/strong>\u00a0 a white calcium-carbonate rich layer within soils in arid regions<\/p>\n

calving<\/strong>\u00a0 the loss of ice from the front of a glacier by collapse into water<\/p>\n

Canadian Shield<\/strong>\u00a0 the exposed part of the continent Laurentia<\/p>\n

carbonate<\/strong> a mineral for which the anion is CO3<\/sub>-2<\/sup>carbonate compensation depth<\/strong>\u00a0 the depth in the ocean below which carbonate minerals are soluble<\/p>\n

cation<\/strong>\u00a0 a positively charged ion<\/p>\n

cementation<\/strong>\u00a0 the process by which minerals are precipitated between grains in sediments, locking the grains together<\/p>\n

Cenozoic<\/strong>\u00a0 the most recent of the eras, representing the past 65.5 Ma of geological time<\/p>\n

chemical<\/strong> sedimentary rock<\/strong>\u00a0 a sedimentary rock comprised of material that was transported as ions in solution, then precipitated by inorganic means (e.g., precipitation triggered by evaporation)<\/p>\n

chemical weathering<\/strong>\u00a0 chemical reactions at Earth’s surface which break down rocks and minerals<\/p>\n

chernozem<\/strong>\u00a0 black soil typical of grasslands in cold climates such as the Canadian Prairies<\/p>\n

chert<\/strong>\u00a0 very fine-grained sedimentary rock formed almost entirely of silica<\/p>\n

chilled margin<\/strong>\u00a0 edges of a pluton which cool rapidly through contact with country rock, resulting in finer grain sizes than in the interior of the pluton<\/p>\n

chlorite<\/strong>\u00a0 ferromagnesian sheet silicate mineral, typically present as fine crystals and forming from the low-temperature metamorphism of mafic rock<\/p>\n

cinder cone<\/strong>\u00a0 steep-sided volcano comprised almost entirely of loose rock fragments, and typically formed during a single eruptive event<\/p>\n

cirque<\/strong>\u00a0 a steep-sided semi-circular basin eroded by an alpine glacier at the head of its valley<\/p>\n

clast<\/strong>\u00a0 a sedimentary fragment of mineral or rock<\/p>\n

clastic sedimentary rock<\/strong>\u00a0 a sedimentary rock comprised of material that was transported as clasts or fragments<\/p>\n

clay<\/strong>\u00a0 sediment particle that is less than 1\/256 mm in diameter<\/p>\n

clay mineral<\/strong>\u00a0 a hydrous sheet-silicate mineral that typically exists as clay-sized grains<\/p>\n

claystone<\/strong>\u00a0 a sedimentary rock comprised mostly of clay-sized grains<\/p>\n

cleavage<\/strong>\u00a0 tendency for a mineral to break along smooth planes that are predetermined by its lattice structure<\/p>\n

climate feedback<\/strong>\u00a0 a case in which the effects of a climate forcing trigger other changes which either amplify or mute the effects of the initial forcing<\/p>\n

climate forcing<\/strong>\u00a0 a mechanism, such as a change in greenhouse gas levels, that causes the climate to change<\/p>\n

coal\u00a0 <\/strong>an organic sedimentary rock formed by the compression and heating of vegetative organic matter. Types of coal include lignite, bituminous coal, and anthracite.<\/p>\n

coal-bed methane<\/strong>\u00a0 methane that is trapped within the pores of coal within a coal seam<\/p>\n

coastal straightening<\/strong>\u00a0 the tendency for an irregular coast to be straightened over time by coastal erosion processes<\/p>\n

cobble<\/strong>\u00a0 sediment particle that is between 64 and 256 mm in diameter<\/p>\n

col<\/strong>\u00a0 the low point or pass along a ridge between two glacial valleys<\/p>\n

columnar jointing<\/strong>\u00a0 the fractures in volcanic rock forming columns that are typically 6-sided, resulting from cooling and contraction of the rock<\/p>\n

composite volcano (or stratovolcano)<\/strong>\u00a0 a volcano that is constructed of alternating layers of pyroclastic debris and lava flows<\/p>\n

concentrate<\/strong> (mining)\u00a0 a product of ore processing that includes a specific ore mineral, separated from the rest of the rock<\/p>\n

concordant<\/strong>\u00a0 parallel to pre-existing layering or foliation within a rock<\/p>\n

cone of depression<\/strong>\u00a0 the depression of the water table around a well that is heavily pumped<\/p>\n

confined aquifer<\/strong>\u00a0 an aquifer that lies below a confining layer<\/p>\n

confining layer<\/strong>\u00a0 an aquitard that overlies an aquifer and restricts the flow of water down from the surface<\/p>\n

confining pressure<\/strong>\u00a0 pressure resulting from the weight of overlying rocks<\/p>\n

conglomerate<\/strong>\u00a0 a sedimentary rock that is comprised predominantly of rounded grains that are larger than 2 mm<\/p>\n

contact metamorphism<\/strong>\u00a0 metamorphism that takes place adjacent to a source of heat, such as a body of magma<\/p>\n

continental drift<\/strong>\u00a0 the concept that tectonic plates can move across the surface of the Earth<\/p>\n

continental glacier<\/strong>\u00a0 a glacier that covers a significant part of a continent and has an area of at least 50,000 km2<\/sup>continental shelf<\/strong>\u00a0 the shallow (typically less than 200 m) and flat sub-marine extension of a continent<\/p>\n

continental slope<\/strong>\u00a0 the steeper part of a continental margin, that slopes down from a continental shelf towards the abyssal plain<\/p>\n

contractionism<\/strong>\u00a0 the now discredited theory that mountain ranges formed as a result of the contraction of the Earth<\/p>\n

convergent boundary<\/strong>\u00a0 a plate boundary at which the two plates are moving towards each other<\/p>\n

Cordilleran Ice Sheet<\/strong>\u00a0 the continental glacier that covered part of western North America, including almost all of British Columbia, part of the Yukon, and part of northern Washington, during the Pleistocene glaciations<\/p>\n

core<\/strong>\u00a0 the metallic interior part of the Earth, extending from a depth of 2900 km to Earth’s centre<\/p>\n

core-mantle boundary (CMB)<\/strong>\u00a0 the boundary, at 2900 km depth, between the mantle and the core<\/p>\n

Coriolis effect<\/strong>\u00a0 the tendency for moving bodies (e.g., ocean currents) to rotate on the surface of the Earth, clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere<\/p>\n

cosmic microwave background (CMB)<\/strong>\u00a0 a radiation “fog” left over from the an early stage in the development of the universe, when the universe was too dense to allow photons to travel far without being scattered<\/p>\n

country rock<\/strong>\u00a0 the original rock of a region, into which younger rock (typically igneous) rock has been intruded<\/p>\n

covalent bond<\/strong>\u00a0 a bond between two atoms in which electrons are shared<\/p>\n

crater<\/strong>\u00a0 a volcanic depression that is related to a specific volcanic vent<\/p>\n

craton<\/strong>\u00a0 a region of ancient (typically Precambrian) crystalline rock (equivalent to a shield)<\/p>\n

creep<\/strong>\u00a0 the very slow (mm to cm per year) flow of unconsolidated material on a gentle slope<\/p>\n

crest<\/strong>\u00a0 the highest point on a wave<\/p>\n

crevasse<\/strong>\u00a0 an open fissure on the surface of a glacier<\/p>\n

cross bedding<\/strong>\u00a0 small-scale inclined bedding within larger horizontal beds<\/p>\n

crust<\/strong>\u00a0 the uppermost layer of the Earth, ranging in thickness from about 5 km (in the oceans) to over 50 km (on the continents)<\/p>\n

cryptocrystalline<\/strong>\u00a0 refers to the texture of a rock or mineraloid in which crystals are so small that they are almost undetectable even with magnification<\/p>\n

cyanobacteria<\/strong>\u00a0 photosynthetic bacteria that evolved in the early Archean<\/p>\n

<\/a>D<\/h2>\n

D” layer<\/strong> (d-double-prime layer)\u00a0 a low seismic velocity zone within the basal 200 km of the mantle<\/p>\n

debris flow<\/strong>\u00a0 a gravity-driven flow of water and sediment that includes a significant proportion of coarse (cobble to boulder) material<\/p>\n

decline<\/strong> (mining)\u00a0 a sloped tunnel used to access lower parts of a mine with wheeled equipment<\/p>\n

decompression melting<\/strong>\u00a0 melting (or partial melting) of rock resulting from a reduction in pressure without a significant reduction in temperature<\/p>\n

Deep time (geologic time).<\/strong> The long timescales (millions to billions of years) over which geologic processes happen.<\/span><\/p>\n

dendritic<\/strong>\u00a0 a pattern of drainage channels that resembles the branches in a tree<\/p>\n

density<\/strong>\u00a0 weight per volume of a substance (e.g., g\/cm3<\/sup>)<\/p>\n

deposition<\/strong>\u00a0 when sediments are dropped out of the medium carrying them, and begin to accumulate in layers<\/p>\n

deranged<\/strong> (drainage)\u00a0 a pattern of drainage channels that is chaotic<\/p>\n

detrital<\/strong>\u00a0 referring to fragments of rocks or minerals<\/p>\n

diatom<\/strong>\u00a0 photosynthetic algae that make their tests (shells) from silica<\/p>\n

differentiation<\/strong>\u00a0 the un-mixing of a molten planetary body, resulting in the formation of a metallic core and a silicate mantle<\/p>\n

dike<\/strong>\u00a0 a tabular intrusive igneous body that is discordant to any existing layering in the country rock<\/p>\n

diorite<\/strong>\u00a0 an intermediate intrusive igneous rock<\/p>\n

dip<\/strong>\u00a0 the angle below horizontal at which a sedimentary bed or other feature slopes<\/p>\n

directed pressure <\/strong>(also, differential stress, directional pressure) pressure which is greater in one direction than in others (e.g., compression, tension)<\/p>\n

discharge<\/strong>\u00a0 the volume of water flow in a stream expressed in terms of volume per unit time (e.g., m3<\/sup>\/s)<\/p>\n

discharge area<\/strong>\u00a0 the part of an aquifer where groundwater discharge takes place<\/p>\n

disconformity<\/strong>\u00a0 a boundary between parallel sedimentary layers where some erosion of the lower layer has taken place<\/p>\n

discordant<\/strong>\u00a0 when a geological feature is not parallel to any existing layering in the country rock<\/p>\n

dissolution<\/strong>\u00a0 when water molecules take a substance apart by capturing its ions and keeping them separated (a type of chemical weathering)<\/p>\n

divalent<\/strong>\u00a0 an ion with a charge or +2 or -2<\/p>\n

divergent<\/strong>\u00a0 a plate boundary at which the two plates are moving away from each other<\/p>\n

dodecahedron<\/strong> an object with twelve surfaces, such as a garnet crystal<\/p>\n

dolomite<\/strong> a calcium-magnesium carbonate mineral (Ca,Mg)CO3<\/sub>. Also, a rock made out of that mineral (see also dolostone)<\/p>\n

dolomitization<\/strong>\u00a0 the addition of magnesium to limestone during which some or all of the calcium carbonate is converted to dolomite<\/p>\n

dolostone<\/strong>\u00a0 a carbonate rock made up primarily of the mineral dolomite<\/p>\n

drainage basin<\/strong>\u00a0 the catchment area of a stream, including the area where all surface water drains into the stream<\/p>\n

drop stone<\/strong>\u00a0 a fragment of rock within otherwise fine-grained sediment that has been dropped from floating ice on a body of water<\/p>\n

drumlin<\/strong>\u00a0 a streamlined glacial erosional feature comprised of sediments and\/or bedrock<\/p>\n

dyke <\/strong>see dike<\/em>
\n<\/strong><\/p>\n

<\/a>E<\/h2>\n

eccentricity<\/strong>\u00a0 (Milankovitch cycles) the degree to which the sun is offset from the geometric centre of the Earth\u2019s orbit<\/p>\n

eclogite<\/strong>\u00a0 a garnet-pyroxene-glaucophane bearing rock that is the product of high-pressure metamorphism of oceanic crustal rock, typically within a subduction zone<\/p>\n

effusive<\/strong>\u00a0 a volcanic eruption dominated by the relatively gentle flow of lava<\/p>\n

El Ni\u00f1o<\/strong>\u00a0 a periodic climatic situation in which warm water extends all or most of the way to the eastern edge of the equatorial Pacific<\/p>\n

elastic deformation<\/strong> deformation from which a material can fully recover if the stress is removed<\/p>\n

electron<\/strong>\u00a0 sub-atomic particle with a single negative charge<\/p>\n

end moraine<\/strong> sediment deposit that accumulates at the front of a glacier<\/p>\n

englacial<\/strong>\u00a0 within a glacier, referring especially to sediment carried within the glacial ice<\/p>\n

epicentre<\/strong>\u00a0 the location on the surface vertically above the location (i.e., \u201chypocentre\u201d or \u201cfocus\u201d) where an earthquake takes place<\/p>\n

epipelagic zone<\/strong>\u00a0 the upper layer of water (0 to 200 m) in areas of the open ocean<\/p>\n

epithermal deposit<\/strong>\u00a0 a mineral deposit formed near to surface in an area of hydrothermal activity, typically associated with a body of magma<\/p>\n

equilibrium line<\/strong> (glacier)\u00a0 the line between the zone of accumulation and the zone of ablation (in late summer the equilibrium line is the boundary between snow-covered ice and bare ice)<\/p>\n

equipotential lines<\/strong> (groundwater) \u00a0 lines connecting locations with equal hydraulic head or water pressure<\/p>\n

erosion<\/strong>\u00a0 the process of transporting sediments away from their source<\/p>\n

esker<\/strong>\u00a0 a ridge of sediment deposited by a sub-glacial stream<\/p>\n

eustatic sea level change<\/strong>\u00a0 sea level change related to a change in the volume of the oceans, typically because of an increase or decrease in the amount of glacial ice on land<\/p>\n

evaporite<\/strong>\u00a0 a chemical sedimentary rock that forms when evaporation concentrates the ions in a solution to the point where they begin to precipitate out<\/p>\n

exfoliation<\/strong>\u00a0 (weathering) the fracturing of rock that results from a reduction in the pressure when overlying rock is eroded away<\/p>\n

exoplanet<\/strong>\u00a0 a planet that orbits a star other than the sun<\/p>\n

extrusive<\/strong>\u00a0 igneous rock that cooled at Earth’s surface<\/p>\n

<\/a>F<\/h2>\n

fall<\/strong>\u00a0 (mass wasting) the vertical or near-vertical downward movement of rock<\/p>\n

fault<\/strong>\u00a0 boundary in rock or sediment along which displacement has taken place<\/p>\n

feedback<\/strong>\u00a0 when one process triggers others which either amplify or mute the original process<\/p>\n

feldspar<\/strong>\u00a0 a very common framework silicate mineral<\/p>\n

feldspathic arenite<\/strong>\u00a0 a sandstone consisting predominantly of sand-sized grains and cement (less than 15% fine-grained matrix), and with more than 10% feldspar grains<\/p>\n

felsic<\/strong>\u00a0 silica rich (>65% SiO2<\/sub>) in the context of magma or igneous rock<\/p>\n

ferric<\/strong>\u00a0 the oxidized form of an ion of iron (Fe3+<\/sup>)<\/p>\n

ferromagnesian<\/strong> referring to a silicate mineral that contains iron and or magnesium<\/p>\n

ferrous<\/strong>\u00a0 the reduced (non-oxidized) form of an ion of iron (Fe2+<\/sup>)<\/p>\n

fetch<\/strong>\u00a0 the distance over which wind blows to form waves<\/p>\n

finger lake<\/strong>\u00a0 a lake that occupies a glacial valley<\/p>\n

firn<\/strong>\u00a0 the granular transitional state between snow and ice within a glacier<\/p>\n

flood plain<\/strong>\u00a0 the area that is occupied by water when a stream floods and overtops its banks<\/p>\n

flow<\/strong>\u00a0 a mass-wasting event where material moves which is saturated with water<\/p>\n

flow path<\/strong>\u00a0 the path that groundwater flows along between a recharge area and a discharge area<\/p>\n

flowing artesian well<\/strong>\u00a0 an artesian well in which the water level naturally rises above the surface of the ground<\/p>\n

flux melting<\/strong>\u00a0 melting of rock that is facilitated by the addition of a flux (typically water) which lowers the rock’s melting point<\/p>\n

focus<\/strong> (earthquake)\u00a0 the actual point below surface at which an earthquake takes place (equivalent to hypocentre)<\/p>\n

foliation<\/strong>\u00a0 the alignment of mineralogical or structural features of a rock \u2013 especially a metamorphic rock<\/p>\n

footwall<\/strong>\u00a0 the lower surface of a non-vertical fault<\/p>\n

foraminifera<\/strong>\u00a0 single-celled protist with a shell that is typically made of CaCO3<\/sub>fore-reef<\/strong>\u00a0 the zone on the ocean side of a reef<\/p>\n

formation<\/strong>\u00a0 a unit of sedimentary rock that is lithologically consistent and sufficiently thick and extensive to be shown on a geological map at the scale that is typically used in the area in question<\/p>\n

fracking<\/strong>\u00a0 fracturing rock by injecting water and chemicals down a well at very high pressure (equivalent to hydraulic fracturing)<\/p>\n

fractional crystallization<\/strong>\u00a0 the sequential crystallization of minerals from magma, and the physical separation of early-forming crystals from the magma in the area where they crystallized<\/p>\n

fracture<\/strong>\u00a0 a break within a body of rock in which the rock on either side is not displaced<\/p>\n

fringing reef<\/strong>\u00a0 a reef adjacent to a shoreline where there is either a very narrow back reef area or none at all (in which case the reef is effectively attached to the shore)<\/p>\n

frost line<\/strong> (also, snow line)\u00a0 in the context of newly forming planetary systems, the distance beyond a star at which volatile components (e.g., water, carbon dioxide, methane, ammonia etc.) are frozen<\/p>\n

frost wedging<\/strong> physical weathering caused when the expansion of freezing water pries rock apart<\/p>\n

<\/a>G<\/h2>\n

Ga<\/strong>\u00a0 (giga annum) billions of years before the present<\/p>\n

gabbro<\/strong>\u00a0 a mafic intrusive igneous rock<\/p>\n

Gaia hypothesis<\/strong>\u00a0 the hypothesis advanced by James Lovelock that the organisms have affected the atmosphere and oceans such that conditions on Earth have been kept habitable, in spite of significantly changing energy received from the Sun<\/p>\n

galaxy<\/strong>\u00a0 gravitationally-bound system of stars and interstellar matter<\/p>\n

gas giant<\/strong>\u00a0 a large planet composed mostly of hydrogen and helium (e.g. Jupiter)<\/p>\n

Geological time (deep time).<\/strong> The long timescales (millions to billions of years) over which geologic processes happen.<\/span><\/p>\n

Geology. <\/strong>The study of Earth, its materials, and the natural processes acting on and within it.<\/span><\/p>\n

geosyncline<\/strong>\u00a0 kilometres thick deposit of sediments that has accumulated along the edge of a continent and is sufficient mass to depress the crust beneath it<\/p>\n

geothermal gradient<\/strong>\u00a0 the rate of increase of temperature with depth in the Earth (typically around 30\u02daC\/km within the crust)<\/p>\n

giant impact hypothesis<\/strong>\u00a0 the theory that the Moon formed when a Mars-sized planet (Theia) collided with the Earth at 4.5 Ga<\/p>\n

glacial period<\/strong>\u00a0 a period of Earth\u2019s history during which glacial ice was present over a sufficient extent to have left recognizable evidence<\/p>\n

glacial groove<\/strong>\u00a0 a straight line created on a rock surface by erosion by a rock fragment embedded in the base of glacial ice (larger and deeper than a glacial striation)<\/p>\n

glacial striation<\/strong>\u00a0 a straight line created on a rock surface by erosion by a rock fragment embedded in the base of glacial ice (finer than a glacial groove \u2013 typically less than 1 cm wide)<\/p>\n

glacier<\/strong>\u00a0 a long lasting (centuries or more) body of ice on land that moves under its own weight<\/p>\n

glaciofluvial<\/strong>\u00a0 referring to sediments deposited from a stream that is derived from a glacier<\/p>\n

glaciolacustrine<\/strong>\u00a0 referring to sediments deposited within a lake in a glacial environment<\/p>\n

glaciomarine<\/strong> \u00a0 referring to sediments deposited within the ocean in a glacial environment<\/p>\n

glaucophane<\/strong>\u00a0 a blue sodium-magnesium-bearing amphibole mineral that forms during metamorphism at high pressures and relatively low pressures, typically within a subduction zone<\/p>\n

gneiss<\/strong>\u00a0 high-grade foliated metamorphic rock in which the mineral components are separated into bands of different composition<\/p>\n

graben<\/strong> a down-dropped fault block, bounded on either side by normal faults<\/p>\n

grade<\/strong>\u00a0 1. (mineral deposit) the amount of a specific metal or mineral expressed as a proportion of the whole rock. 2. (coal) the extent to which carbon has been concentrated within the coal, and the possible energy output on combustion has increased<\/p>\n

graded bedding<\/strong>\u00a0 an individual sedimentary layer that shows a distinctive gradation in grain size (normal graded bedding is finer towards the top, reverse graded bedding is coarser towards the top)<\/p>\n

gradient<\/strong>\u00a0 the slope of a stream bed over a specific distance, typically expressed in m per km<\/p>\n

grain size<\/strong>\u00a0 the diameter of a fragment (clast) of sediment<\/p>\n

granite<\/strong>\u00a0 a felsic intrusive igneous rock<\/p>\n

granule<\/strong>\u00a0 a sedimentary particle ranging in size from 2 to 4 mm in diameter<\/p>\n

greenhouse gas\u00a0<\/strong> a gaseous molecule with 3 or more atoms that is able to absorb infrared radiation<\/p>\n

greenhouse effect<\/strong> (climate) the ability of an atmosphere to absorb infrared radiation due to the presence of greenhouse gases<\/p>\n

greenschist<\/strong>\u00a0 1. (metamorphic rock) a foliated metamorphosed rock (typically derived from basalt) in which the green colouration is derived from either chlorite, epidote, or green amphibole. 2. (metamorphic facies) low-grade metamorphic facies characteristic of regional metamorphism<\/p>\n

greenstone<\/strong>\u00a0 a non-foliated metamorphosed rock (typically derived from basalt) in which the green colouration is derived from either chlorite, epidote or green amphibole. Can be formed by hydrothermal metamorphism on the ocean floor.<\/p>\n

greywacke<\/strong>\u00a0 a sandstone with more than 15% silt and clay, and with a significant proportion of sand-sized rock fragments<\/p>\n

groundwater<\/strong>\u00a0 water that lies beneath the surface of the ground<\/p>\n

group<\/strong>\u00a0 a stratigraphically continuous series of related formations<\/p>\n

groyne<\/strong>\u00a0 a man-made structure extending from the shore built to deflect the energy of waves<\/p>\n

gyre<\/strong>\u00a0 a closed circular ocean current<\/p>\n

<\/a>H<\/h2>\n

habit<\/strong>\u00a0 a characteristic crystal form or combination of forms of a mineral<\/p>\n

habitable zone<\/strong>\u00a0 the region around a star that is considered to be suitable for a life-bearing planet<\/p>\n

Hadean<\/strong>\u00a0 the first eon of Earth history, extending from 4.57 to 3.80 Ga<\/p>\n

halide<\/strong>\u00a0 a mineral in which the anion is one of the halide elements (e.g., halite \u2013 NaCl or fluorite – CaF2<\/sub>)<\/p>\n

halite<\/strong>\u00a0 NaCl, a halide mineral which consititutes table salt<\/p>\n

halogen<\/strong> an element in the second-last column of the periodic table that forms anions with a negative-1 charge<\/p>\n

hanging valley<\/strong>\u00a0 a glacial valley created by a tributary glacier which does not erode as deeply as the main-valley glacier that it joins<\/p>\n

hanging wall<\/strong>\u00a0 the upper surface of a non-vertical fault<\/p>\n

headland<\/strong>\u00a0 a point extending out to sea<\/p>\n

horn<\/strong>\u00a0 a peak that has been eroded on at least three sides by glaciers<\/p>\n

hornfels<\/strong>\u00a0 a fine-grained metamorphic rock that is not foliated. It can have a variety of parent rocks.<\/p>\n

horst<\/strong>\u00a0 an uplifted fault block, bounded on either side by normal faults<\/p>\n

hot spot<\/strong>\u00a0 the surface area of volcanism and high heat flow above a mantle plume<\/p>\n

hydrated mineral<\/strong>\u00a0 a mineral that includes either hydroxyl (OH) or water (H2<\/sub>O) in its chemical formula (e.g., gypsum CaSO4<\/sub>.2H2<\/sub>O)<\/p>\n

hydraulic conductivity<\/strong>\u00a0 an expression of the rate at which a liquid will flow through a porous medium, as determined by the permeability of the medium and the viscosity of the liquid<\/p>\n

hydraulic fracturing<\/strong>\u00a0 fracturing rock by injecting water and chemicals down a well at very high pressure (equivalent to fracking)<\/p>\n

hydrolysis<\/strong>\u00a0 a reaction between a mineral and water in which H+ ions are added to the mineral and a chemically equivalent amount of cations are released into solution<\/p>\n

hydrothermal\u00a0 <\/strong>refers to hot water solutions and processes involving hot water solutions<\/p>\n

hydrothermal alteration<\/strong>\u00a0 chemical alteration of minerals by hot water solutions<\/p>\n

hydroxide<\/strong>\u00a0 the anion OH–<\/sup> or an mineral that includes that anion<\/p>\n

hypocentre<\/strong>\u00a0 the actual point below surface at which an earthquake takes place (equivalent to focus)<\/p>\n

Hypothesis.<\/strong> An informed speculation about how the world works. Scientific hypotheses must be testable.<\/span><\/p>\n

<\/a>I<\/h2>\n

ice giant<\/strong>\u00a0 a planet that is comprised mainly of gases heavier than hydrogen and helium, including oxygen,\u00a0carbon,\u00a0nitrogen, and\u00a0sulfur (e.g., Uranus and Neptune)<\/p>\n

igneous<\/strong>\u00a0 a rock formed from the cooling of magma<\/p>\n

illite<\/strong>\u00a0 a clay mineral with a composition similar to that of muscovite mica<\/p>\n

imbricate<\/strong>\u00a0 aligned and overlapping, like the tiles on a roof<\/p>\n

index fossil<\/strong>\u00a0 a fossil with a distinctive appearance and a wide geographic range but from a relatively restricted time range, thus making it useful for dating a correlating rocks from different regions (the most useful index fossils are from organisms that lived for less than a million years)<\/p>\n

index mineral\u00a0 <\/strong>(metamorphic rocks) a mineral with a stability range of pressures and temperatures sufficiently narrow so as to be useful in indicating the pressures and temperatures at which a metamorphic rock formed.<\/p>\n

inert<\/strong>\u00a0 in chemistry, an element that does not readily react with other elements (e.g., neon)<\/p>\n

infiltration<\/strong>\u00a0 the recharge of groundwater from the downward percolation of surface water<\/p>\n

insolation<\/strong>\u00a0 a measure of the intensity of solar energy at a specific location or time (expressed in W\/m2)<\/p>\n

intensity<\/strong>\u00a0 in seismology, a qualitative measure of the amount of shaking at specific location, based on what was felt by observers, or the amount of damage done<\/p>\n

Intergovernmental Panel on Climate Change<\/strong>\u00a0 (IPCC) an international body established in 1988 by the UN\u2019s World Meteorological Organization and the UN Environment Program to prepare periodic reports on the status of global climate change and its mitigation<\/p>\n

intrusive<\/strong>\u00a0 an igneous rock (pluton) that has cooled slowly beneath the surface<\/p>\n

ionic bond<\/strong>\u00a0 a bond in which electrons are transferred from one atom to another, thus forming ions<\/p>\n

ion<\/strong>\u00a0 an atom that has either gained or lost electrons and has thus become charged (or a group of atoms that also has a charge \u2013 e.g., HCO3<\/sub>–<\/sup>)<\/p>\n

isoclinal fold<\/strong>\u00a0 a tight fold in which the limbs are parallel to each other<\/p>\n

isostasy<\/strong>\u00a0 the equilibrium between a block of crust floating on the underlying plastic mantle<\/p>\n

isostatic sea-level change<\/strong>\u00a0 the effect on relative sea level of a vertical adjustment of the crust resulting from a change in the mass of the crust (e.g., from losing or gaining ice)<\/p>\n

isotherm<\/strong>\u00a0 a surface or line drawn to represent points at the same temperature. (iso<\/em> = same)<\/p>\n

isotope<\/strong> a form of an element that differs from other forms because it has a different number of neutrons (e.g., 16<\/sup>O has 8 protons and 8 neutrons while 18<\/sup>O has 8 protons and 10 neutrons)<\/p>\n

<\/a>J<\/h2>\n

joint<\/strong>\u00a0 a fracture in rock where the rock on one side has not moved relative to the other side<\/p>\n

jointing<\/strong>\u00a0 the formation of joints<\/p>\n

Jovian planet<\/strong>\u00a0 a gas giant planet<\/p>\n

<\/a>K<\/h2>\n

ka<\/strong> (kilo annum) thousands of years before the present<\/p>\n

kaolinite<\/strong>\u00a0 a clay mineral that does not have cations other than Al and Si<\/p>\n

karst<\/strong>\u00a0 the solutional erosion of an area with soluble rock (typically limestone) to form depressions and caves<\/p>\n

kettle<\/strong>\u00a0 a depression formed at the front of a large glacier when a stranded ice block that was surrounded by sediment eventually melts<\/p>\n

kettle lake<\/strong>\u00a0 a lake that forms within a kettle<\/p>\n

kimberlite<\/strong>\u00a0 an ultramafic volcanic rock that originates at significant depth (> 200 m) in the mantle (some kimberlites include diamonds)<\/p>\n

Kuiper belt<\/strong>\u00a0 a region of the Solar System beyond the orbit of Neptune that is populated by small objects and dwarf planets (including Pluto)<\/p>\n

<\/a>L<\/h2>\n

laccolith<\/strong>\u00a0 concordant intrusion in which the central part has bulged upward<\/p>\n

lahar<\/strong>\u00a0 a mudflow or debris flow that is either caused by a volcanic eruption, or forms on the flank of a volcano as a result of flooding not related to an eruption<\/p>\n

landfill gas<\/strong>\u00a0 gases produced within a landfill during the microbial breakdown of landfill components (most are dominated by carbon dioxide and methane)<\/p>\n

large igneous province (LIP)<\/strong>\u00a0 a very large area of mafic volcanic rock produced by a massive eruption typically related to a mantle plume<\/p>\n

lateral moraine<\/strong>\u00a0 a deposit of rocky material that forms along the margin of a valley or alpine glacier, mostly from the freeze-thaw release of material from the steep slopes above<\/p>\n

lattice<\/strong>\u00a0 the regular and repeating three-dimensional structure of a mineral<\/p>\n

Laurentide Ice Sheet<\/strong>\u00a0 the continental glacier that extended across central eastern North America during the Pleistocene, covering most of Canada and a significant part of the United States<\/p>\n

lava<\/strong>\u00a0 molten rock on Earth’s surface (cf. magma)<\/p>\n

lava lev\u00e9e<\/strong>\u00a0 a ridge that forms along the edge of a lava flow because the magma at the edge cools faster than that in the middle<\/p>\n

lava tube<\/strong>\u00a0 a tube that forms as mafic lava flows along a channel and lava leve\u00e9s build up on either side, eventually forming a roof (once a lava tube forms it insulates the flowing magma, allowing it to stay hot a liquid for longer and therefore flow much further)<\/p>\n

Law.<\/strong> A description that always applies to a scientific phenomenon, given specific conditions.<\/span><\/p>\n

leachate<\/strong>\u00a0 in the context of landfills, the liquid (rainwater) that passes through the waste and becomes contaminated with soluble components from the waste<\/p>\n

lev\u00e9e<\/strong>\u00a0 on a stream, the ridge that naturally forms along the edge of the channel during flood events<\/p>\n

level<\/strong>\u00a0 in mining, a horizontal mine opening<\/p>\n

light year<\/strong>\u00a0 the distance that light can travel in one year (9.4607 x 1012<\/sup> km)<\/p>\n

lignite<\/strong>\u00a0 a low-grade type of coal with less than 70% carbon<\/p>\n

limbs<\/strong>\u00a0 the layers of rock on either side of a fold<\/p>\n

limestone<\/strong>\u00a0 a biochemical sedimentary rock that is comprised mostly of calcite<\/p>\n

liquefaction<\/strong>\u00a0 the tendency for unconsolidated and water saturated sediments to lose strength during seismic shaking<\/p>\n

lithic arenite<\/strong>\u00a0 an arenite in which there is more than 10% lithic clasts and in which there are more lithic clasts than feldspar clasts (see also arenite<\/em>)<\/p>\n

lithic clasts<\/strong>\u00a0 fragments of another rock which are included in the sand-sized grains in sandstone, or in the larger grains in conglomerate<\/p>\n

lithification<\/strong>\u00a0 the conversion of unconsolidated sediments into rock by compaction and cementation<\/p>\n

lithosphere<\/strong>\u00a0 the rigid outer part of the Earth, including the crust and the mantle down to a depth of about 100 km<\/p>\n

lithostatic pressure<\/strong>\u00a0 pressure due to the weight of overlying rocks<\/p>\n

lodgement till<\/strong>\u00a0 sediment that accumulates at the base of a glacier and typically has a wide range of grain sizes (including clay) and is well compacted<\/p>\n

long axis<\/strong>\u00a0 in a crystal, clast, or grain, the direction in which the length would be the greatest<\/p>\n

longshore current<\/strong>\u00a0 the movement of water along a shoreline produced by the approach of waves at an angle to the shore<\/p>\n

longshore drift<\/strong>\u00a0 the movement of sediment along a shoreline resulting from a longshore current and also from the swash and backwash on a beach face<\/p>\n

Love wave<\/strong>\u00a0 a surface seismic wave, with horizontal motion, that develops in relatively weak (e.g., unconsolidated) materials at surface<\/p>\n

luvisol<\/strong>\u00a0 a cold climate forest soil formed in which clay has been removed from the A horizon and relocated into the B horizon<\/p>\n

<\/a>M<\/h2>\n

Ma<\/strong> (Mega annum) millions of years before the present<\/p>\n

mafic<\/strong>\u00a0 silica poor (<45% SiO2) in the context of magma or igneous rock, and containing ferromagnesian minerals such as olivine and pyroxene)<\/p>\n

magma<\/strong>\u00a0 molten rock within Earth’s interior (cf. lava<\/em>)<\/p>\n

magnetic chronology<\/strong>\u00a0 the study of the timing of reversals of the Earth\u2019s magnetic field, and the application of that understanding to dating geological materials<\/p>\n

magnitude<\/strong>\u00a0 a measure of the amount of energy released by an earthquake<\/p>\n

mantle<\/strong>\u00a0 the middle layer of the Earth, dominated by iron and magnesium rich silicate minerals and extending for about 2900 km from the base of the crust to the top of the core<\/p>\n

mantle plume<\/strong>\u00a0 a plume of hot rock (not magma) that rises through the mantle (either from the base or from part way up) and reaches the surface where it spreads out and also leads to hot-spot volcanism<\/p>\n

marble<\/strong>\u00a0 a non-foliated metamorphic rock derived from a limestone or dolostone protolith, in which the calcite or dolomite has been recrystallized into larger crystals<\/p>\n

mass wasting<\/strong>\u00a0 the mass failure, by gravity, of rock or unconsolidated material on a slope<\/p>\n

matrix<\/strong>\u00a0 finer-grained material between larger clasts within a sedimentary rock<\/p>\n

maturity<\/strong>\u00a0 the degree to which a sediment or sedimentary rock exhibits characteristics of prolonged physical and chemical weathering and transpor,t<\/p>\n

meander cutoff<\/strong>\u00a0 the formation of a shorter stream channel across the narrow boundary between two meanders on a stream<\/p>\n

meandering<\/strong>\u00a0 the sinuous path taken by a stream within a wide flat flood plain<\/p>\n

mechanical weathering<\/strong> (also, physical weathering)\u00a0 weathering that occurs when physical processes cause a rock to break into smaller pieces without changing the chemical composition<\/p>\n

medial moraine<\/strong>\u00a0 a lateral moraine that has been shifted towards the centre of a valley glacier at a point where two glaciers meet<\/p>\n

member<\/strong>\u00a0 a subdivision of a formation<\/p>\n

mesopelagic zone<\/strong>\u00a0 the upper middle zone of the open ocean extending from 200 to 1000 m depth<\/p>\n

metallic lustre<\/strong>\u00a0 the lustre of a mineral into which light does not penetrate but reflects off of the surface without being scattered (i.e., shines reflects light like a shiny metal)<\/p>\n

metallic bond<\/strong>\u00a0 a type of bond in which abundant electrons are easily shared amongst cations<\/p>\n

metamorphic facies<\/strong>\u00a0 a group of metamorphic rocks formed under the same range of pressures and temperature conditions, but from different parent rocks<\/p>\n

metamorphic grade<\/strong>\u00a0 refers to the intensity of metamorphism, and increases as pressure and temperature increase<\/p>\n

metamorphism<\/strong>\u00a0 the transformation of a parent rock into a new rock as a result of heat and pressure that leads to the formation of new minerals, or recrystallization of existing minerals, without melting<\/p>\n

metasomatism<\/strong>\u00a0 metamorphism facilitated by ion transfer through water, and which results in a substantial change in the chemical composition (not just the mineral content) of a rock<\/p>\n

meteoroid<\/strong>\u00a0 a small fragment of stony or metallic debris in space<\/p>\n

methane hydrate<\/strong>\u00a0 a combination of water ice and methane in which the methane is trapped inside \u201ccages\u201d in the ice<\/p>\n

mica<\/strong>\u00a0 a sheet-silicate mineral (e.g., biotite, muscovite)<\/p>\n

migmatite<\/strong>\u00a0\u00a0 rock that is part metamorphic and part igneous, formed at\u00a0 very high grades of metamorphism when a part of the parent rock starts to melt<\/p>\n

Milankovitch cycles<\/strong>\u00a0 millennial-scale variations in the orbital and rotational parameters of the Earth that have subtle effects on the Earth\u2019s climate<\/p>\n

Mohorovi\u010di\u0107 discontinuity<\/strong> (Moho) the boundary between the crust and the mantle<\/p>\n

moment magnitude<\/strong>\u00a0 a way of estimating earthquake magnitude based on the area of the rupture surface and the amount of displacement<\/p>\n

monogenetic<\/strong>\u00a0 a volcano that forms in a single eruptive event<\/p>\n

moraine lake<\/strong>\u00a0 a finger lake that forms within a glacial valley and is dammed by an end moraine<\/p>\n

mud crack<\/strong>\u00a0 a dessication crack formed when mud shrinks as it dries<\/p>\n

mudflow<\/strong>\u00a0 a mass-wasting event involving the flow of mud (sand, silt and clay) within a channel<\/p>\n

mudrock<\/strong>\u00a0 an inclusive term for mudstone, shale and claystone<\/p>\n

mudstone<\/strong>\u00a0 a fine-grained clastic sedimentary rock with a mixture of silt-sized and clay-sized particles<\/p>\n

muscovite<\/strong>\u00a0 a potassium-bearing non-ferromagnesian mica<\/p>\n

<\/a>N<\/h2>\n

native element<\/strong> (also, native element mineral) a mineral that consists of only one element (e.g., native gold)<\/p>\n

nebula<\/strong>\u00a0 a large cloud of dust and gas in space, frequently hosting the formation of stars<\/p>\n

negative feedback<\/strong>\u00a0 a process that results in a decrease in that process (in the context of climate change it is a process that reduces the change in climate, such as the enhanced growth of vegetation in response to an increase in atmospheric carbon dioxide)<\/p>\n

neutron<\/strong>\u00a0 a sub-atomic particle with a mass of 1 and a charge of 0<\/p>\n

nonconformity<\/strong>\u00a0 a geological boundary where non-sedimentary rock is overlain by sedimentary rock<\/p>\n

non-ferromagnesian mineral<\/strong>\u00a0 a silicate mineral that does not contain iron or magnesium (e.g., feldsspar)<\/p>\n

non-metallic lustre\u00a0 <\/strong>the lustre of a mineral into which light does penetrate, or which does not produce a bright reflection<\/p>\n

normal fault<\/strong>\u00a0 a non-vertical fault along which the hanging wall (upper surface) has moved down relative to the footwall<\/p>\n

normal force<\/strong>\u00a0 the component of the gravitational force that acts directly into the slope<\/p>\n

North Atlantic Deep Water<\/strong>\u00a0 deep Atlantic Ocean water that has descended in the far north of the basin in the area between Scandinavia and Greenland<\/p>\n

nunatuk<\/strong>\u00a0 a rocky peak that extends above the ice level of a continental glacier<\/p>\n

<\/a>O<\/h2>\n

obliquity<\/strong>\u00a0 (Milankovitch cycles) the angle of the tilt of the Earth\u2019s rotational axis with respect to the plane of its orbit around the sun<\/p>\n

ocean plain<\/strong>\u00a0 the extremely flat surface of the deep ocean floor in areas unaffected by plate tectonic processes and volcanism<\/p>\n

oil window<\/strong>\u00a0 the depth range, which is approximately 2000 to 4000 m, within which the temperature is appropriate for the formation of oil from organic matter in sedimentary rock<\/p>\n

ooid<\/strong>\u00a0 a small (approximately 1 mm) sphere of calcite formed in areas of tropical shallow marine water with strong currents<\/p>\n

olivine<\/strong> a silicate mineral made up of isolated silica tetrahedra and with either iron or magnesium (or both) as the cations<\/p>\n

Oort cloud<\/strong>\u00a0 a spherical cloud of icy objects extending from between about 5,000 and 500,000 astronomical units (Sun-Earth distances) from the Sun (thought to be a source area of comets)<\/p>\n

open-pit mine<\/strong>\u00a0 a mine that is open to the surface<\/p>\n

organic sedimentary rock\u00a0 <\/strong>a sedimentary rock consisting of materials made of carbon-hydrogen bonds (e.g., animal and plant material)<\/p>\n

outcrop<\/strong>\u00a0 a surface exposure of rock that is part of the crust (bedrock)<\/p>\n

outwash plain<\/strong>\u00a0 an extensive region of sand and gravel deposited by streams flowing out of a glacier (same as sandur)<\/p>\n

overturned\u00a0<\/strong> a geological feature that has been tilted to the point where it is upside down<\/p>\n

oxbow<\/strong>\u00a0 a part of a stream meander that has become isolated from the rest of the stream as the result of a meander cutoff<\/p>\n

oxidation<\/strong>\u00a0 the reaction between a mineral and oxygen<\/p>\n

oxide<\/strong>\u00a0 a mineral in which the anion is oxygen (e.g., hematite Fe2<\/sub>O3<\/sub>)<\/p>\n

<\/a>P<\/h2>\n

pahoehoe<\/strong>\u00a0 a lava flow with a ropy surface texture formed when the surface cools and hardens while the lava beneath is still flowing<\/p>\n

paleomagnetic<\/strong>\u00a0 characterized by past variations in the intensity and polarity of the Earth\u2019s magnetic field<\/p>\n

Pangea<\/strong>\u00a0 che supercontinent that existed between approximately 300 and 180 Ma<\/p>\n

paraconformity<\/strong>\u00a0 an interruption representing a period of non-deposition, without tilting or erosion, in a sequence of sedimentary rocks<\/p>\n

parasitic fold<\/strong>\u00a0 a fold within a fold<\/p>\n

parent rock<\/strong> (also, parent material, protolith)\u00a0 the rock that was already in existence when a process of metamorphism started, or the rock from which sediments were derived<\/p>\n

partial melting<\/strong>\u00a0 the process during which a only specific mineral components of a rock melt<\/p>\n

parting<\/strong>\u00a0 a narrow gap between individual sedimentary layers<\/p>\n

passive margin\u00a0<\/strong> a boundary between a continent and an ocean at which there is no tectonic activity (e.g., the eastern edge of North America)<\/p>\n

paternoster lake<\/strong>\u00a0 one of a series of rock basin lakes<\/p>\n

peat<\/strong>\u00a0 a product of the first stage of coal formation, where vegetative material undergoes limited decomposition in a low-oxygen, acidic environment<\/p>\n

pebble<\/strong>\u00a0 a sedimentary particle ranging in size from 2 to 64 mm (includes granule)<\/p>\n

pelagic<\/strong>\u00a0 the part of a lake or the ocean that is not close to shore<\/p>\n

permafrost<\/strong>\u00a0 ground that remains frozen for two or more years<\/p>\n

permanentism<\/strong>\u00a0 the now discredited theory that the features on the Earth have not changed significantly over geological time<\/p>\n

permeability<\/strong>\u00a0 an expression of the ease with which liquid will flow through a porous medium<\/p>\n

phaneritic<\/strong>\u00a0 a rock texture in which the individual crystals or grains are visible to the naked eye<\/p>\n

Phanerozoic<\/strong>\u00a0 the most resent eon of geological time, encompassing the Paleozoic, Mesozoic and Cenozoic eras<\/p>\n

phenocryst<\/strong>\u00a0 a relatively large crystal within an igneous rock<\/p>\n

phyllosilicate<\/strong>\u00a0 a silicate mineral in which the silica tetrahedra are made up of sheets<\/p>\n

phosphate<\/strong>\u00a0 a mineral in which the anion is PO4<\/sub>3-<\/sup>photic zone<\/strong>\u00a0 the upper 200 m of the ocean or a lake, where, depending on the turbidity of the water, light can penetrate<\/p>\n

phreatic eruption<\/strong>\u00a0 a steam-drive volcanic eruption that takes place when surface or near-surface water is heated by volcanic activity<\/p>\n

phyllite<\/strong>\u00a0 a metamorphic rock with slaty cleavage and a sheen on the surface produced by aligned micas<\/p>\n

physical weathering\u00a0 <\/strong>(also, mechanical weathering)\u00a0 <\/em>weathering that occurs when physical processes cause a rock to break into smaller pieces without changing the chemical composition<\/p>\n

pillow<\/strong>\u00a0 a pillow-shaped mass of volcanic rock (typically basalt) formed when magma erupts beneath the surface<\/p>\n

pillow lava<\/strong>\u00a0 a volcanic rock (typically basalt) that is made up primarily of pillows<\/p>\n

pipe<\/strong>\u00a0 a cylindrical body of igneous rock. May feed a volcano or connect plutons<\/p>\n

Plate.<\/strong> A fragment of Earth\u2019s surface consisting of lithosphere (crust and uppermost mantle).<\/span><\/p>\n

Plate tectonics.<\/strong>\u00a0 The concept that the Earth\u2019s crust and upper-most mantle (lithosphere) is divided into a number of plates that move independently on the surface and interact with each other at their boundaries<\/span><\/p>\n

Plinian eruption<\/strong>\u00a0 a large volcanic eruption in which a column of hot tephra and gases rises many kilometres into the atmosphere<\/p>\n

pluton<\/strong>\u00a0 a body of igneous rock formed by cooling within the Earth (i.e., a body of intrusive igneous rock)<\/p>\n

podzol<\/strong>\u00a0 a soil with well-developed horizons formed in temperate forested regions<\/p>\n

podzolization<\/strong>\u00a0 the process of the formation of podsol<\/p>\n

polar wandering path<\/strong>\u00a0 see: apparent polar wandering path<\/p>\n

polymerize<\/strong>\u00a0 the formation of molecular chains within a fluid (e.g., a magma) that lead to an increase in the fluid\u2019s viscosity<\/p>\n

polymorphs<\/strong>\u00a0 two or more minerals with the same chemical formula but different crystal structures<\/p>\n

porosity<\/strong>\u00a0 the percentage of open pore space within a body of rock or sediment<\/p>\n

porphyritic<\/strong>\u00a0 an igneous texture in which some of the crystals are distinctively larger than the rest<\/p>\n

porphyry deposit<\/strong>\u00a0 a mineral deposit (of copper or molybdenum especially) in which part of the host rock is a porphyritic stock<\/p>\n

positive feedback<\/strong>\u00a0 a process that results in an increase in that process (in the context of climate change it is a process that enhances the change in climate, such as the reduced reflectivity of the Earth\u2019s surface when ice melts)<\/p>\n

potassium feldspar<\/strong>\u00a0 feldspar with the formula KAlSi3<\/sub>O8<\/sub>, and which is a common constituent of felsic igneous rocks<\/p>\n

potentiometric surface<\/strong>\u00a0 the imaginary surface defined by the levels to which water would rise in a series of wells drilled into a confined aquifer<\/p>\n

precession<\/strong> (Milankovitch cycles) the variation in the direction at which the Earth\u2019s rotational axis is pointing<\/p>\n

pressure-release cracking<\/strong>\u00a0 cracking of a rock which occurs when overlying rocks are removed by erosion and the outer layer of the rock expands<\/p>\n

principle of cross-cutting relationships<\/strong>\u00a0 the principle that a body of rock that cuts across or through another body of rock is younger than that other body<\/p>\n

principle of faunal succession<\/strong>\u00a0 the principle that life on Earth has evolved in an orderly way, and that we can expect to always find fossils of a specific type in rocks of a specific age<\/p>\n

principle of inclusions<\/strong>\u00a0 the principle that inclusions within a body of rock must be older than the rock<\/p>\n

principle of original horizontality<\/strong>\u00a0 the principle that sedimentary beds are originally deposited in horizontal layers<\/p>\n

principle of superposition<\/strong>\u00a0 the principle that in a sequence of layered rocks that is not overturned or interrupted by faulting, the oldest will be at the bottom and the youngest at the top<\/p>\n

proglacial<\/strong>\u00a0 referring to the area in front of a glacier<\/p>\n

protolith\u00a0 <\/strong>(also, parent rock) the rock which was altered to produce a metamorphic rock<\/p>\n

proton<\/strong>\u00a0 a sub-atomic particle with a mass of 1 and a charge of 1<\/p>\n

protoplanetary disk<\/strong>\u00a0 a rotating cloud of gas and dust surrounding a young star<\/p>\n

pumice<\/strong>\u00a0 a highly vesicular (filled with holes left by gas bubbles) felsic volcanic rock (typically composed mostly of glass)<\/p>\n

p-wave<\/strong>\u00a0 a seismic body wave that is characterized by deformation of the rock in the same direction that the wave is propagating (compressional vibration)<\/p>\n

pyroclastic<\/strong>\u00a0 volcanic material formed during an explosive eruption<\/p>\n

pyroclastic density current<\/strong>\u00a0 a body of hot pyroclastic rock and gases that is flowing rapidly down the flank of a volcano<\/p>\n

pyroxene<\/strong>\u00a0 a single chain silicate mineral<\/p>\n

<\/a>Q<\/h2>\n

quartz<\/strong>\u00a0 a silicate mineral with the formula SiO2<\/sub>quartz sandstone<\/strong> (also, quartz arenite) a sandstone in which more than 90% of the grains are quartz<\/p>\n

quartzite<\/strong>\u00a0 a non-foliated metamorphic rock formed from the contact or regional metamorphism of sandstone<\/p>\n

<\/a>R<\/h2>\n

radial<\/strong> (drainage) a pattern of streams radiating out from a central point, typically an isolated mountain<\/p>\n

radioactivity\u00a0<\/strong> the natural transformation of unstable isotopes into new elements<\/p>\n

radiolaria<\/strong>\u00a0 microscopic (0.1 to 0.2 mm) marine protozoa that produce silica shells<\/p>\n

Rayleigh wave<\/strong>\u00a0 a surface seismic wave, with vertical motion<\/p>\n

recharge<\/strong>\u00a0 the transfer of surface water into the ground to become groundwater<\/p>\n

recharge area<\/strong>\u00a0 an area of an aquifer where recharge is predominant over discharge<\/p>\n

recrystallization\u00a0 <\/strong>during metamorphism, mineral crystals dissolving and reforming as larger crystals<\/p>\n

rectangular drainage<\/strong> a pattern in which tributaries typically flow at right angles to each other and meet at right angles<\/p>\n

recumbent fold<\/strong>\u00a0 a fold that is overturned such that its limbs are close to horizontal<\/p>\n

redshift<\/strong>\u00a0 the increase in wavelength of light resulting from the fact that the source of the light is moving away from the observer<\/p>\n

reef<\/strong>\u00a0 a mound of carbonate formed in shallow tropical marine environments by corals, algae and a wide range of other organisms<\/p>\n

regional<\/strong> metamorphism<\/strong>\u00a0 metamorphism caused by burial of the parent rock to depths greater than 5 km (typically takes place beneath mountain ranges, and extends over areas of hundreds of km2<\/sup>)<\/p>\n

remnant magnetism<\/strong>\u00a0 magnetism of a body of rock that formed at the time the rock formed and is consistent with the magnetic field orientation that existed at that time and place (see also paleomagnetism<\/em>)<\/p>\n

reservoir rock<\/strong>\u00a0 rock into which petroleum has migrated and is now trapped<\/p>\n

residual soil<\/strong>\u00a0 soil formed by weathering of the underlying rock or sediment<\/p>\n

retrograde metamorphism<\/strong>\u00a0 metamorphism that transforms a higher grade metamorphic rock into a lower grade metamorphic rock<\/p>\n

reverse fault<\/strong>\u00a0 a non-vertical fault along which the hanging wall (upper surface) has moved up relative to the footwall<\/p>\n

rhyolite<\/strong>\u00a0 a felsic volcanic rock<\/p>\n

ridge push<\/strong>\u00a0 the concept that at least part of the mechanism of plate motion is the push of oceanic lithosphere down from a ridge area<\/p>\n

rip current<\/strong>\u00a0 a strong flow of water outward from a beach<\/p>\n

ripple<\/strong>\u00a0 a series of small parallel ridges formed within sediment that has accumulated in moving water or wind<\/p>\n

rip-rap<\/strong>\u00a0 angular rock fragments, typically boulder sized, used to armour slopes and shorelines against erosion<\/p>\n

roche mouton\u00e9e<\/strong>\u00a0 a product of glaciation in which a bedrock protrusion is eroded into a streamlined shape that has a broken or jagged leading (down-ice) edge<\/p>\n

rock avalanche<\/strong>\u00a0 a rapid turbulent flow of broken bedrock fragments down a steep slope<\/p>\n

rock basin lake<\/strong>\u00a0 a lake situated in a rock basin carved at the upper end of an alpine glacier<\/p>\n

rock cleavage\u00a0 <\/strong>the tendency of a rock to break along planes defined by foliation<\/p>\n

rock cycle<\/strong>\u00a0 the series of processes through which rocks are transformed from one type to another<\/p>\n

rock fall \u00a0<\/strong> the near-vertical fall or bouncing of rock released from a steep slope<\/p>\n

rock slide<\/strong>\u00a0 the translational motion of an essentially intact body of rock down a slope (rock slides are typically slow, because once they start to move fast the rock body becomes fragmented and then flows as a rock avalanche)<\/p>\n

root wedging<\/strong>\u00a0 a physical weathering process in which roots grow into cracks in rocks and force them open<\/p>\n

rounding<\/strong>\u00a0 describes the extent to which clasts have had their edges and corners smoothed off<\/p>\n

runoff<\/strong>\u00a0 flow of water down a slope, either across the ground surface, or within a series of channels<\/p>\n

rupture<\/strong>\u00a0 breaking of rock subject to stress, typically resulting in an earthquake<\/p>\n

rupture surface<\/strong>\u00a0 the area over which rock rupture takes place during an earthquake<\/p>\n

<\/a>S<\/h2>\n

sackung<\/strong>\u00a0 an escarpment or trough at the top of a slow-moving rock slide (sackungen)<\/p>\n

saltation<\/strong>\u00a0 the bouncing of particles along a stream bottom or desert floor<\/p>\n

salt wedging<\/strong>\u00a0 a physical weathering process in which water with dissolved salt flows into a crack, and as the water evaporates, salt crystals grow and push the crack open<\/p>\n

sand<\/strong>\u00a0 a mineral or rock fragment ranging in size from 1\/16th to 2 mm<\/p>\n

sandstone<\/strong>\u00a0 a rock that is primarily comprised of sand-sized particles<\/p>\n

sandur<\/strong>\u00a0 an extensive region of sand and gravel deposited by streams flowing out of a glacier (same as outwash plain)<\/p>\n

saturated zone<\/strong>\u00a0 the part of an aquifer, or any body of rock, that is saturated with water<\/p>\n

schist<\/strong>\u00a0 a foliated metamorphic rock with crystals large enough to be visible to the unaided eye<\/p>\n

Scientific method.<\/strong> A way to collect scientific facts in as reliable a way as possible. A hypothesis is formulated and tested. Whether the hypothesis passes or fails the test will determine whether it is kept or discarded.<\/span><\/p>\n

sea cave<\/strong>\u00a0 a shallow cave formed on a rocky shore by wave erosion<\/p>\n

sea cliff<\/strong>\u00a0 a coastal escarpment that is typically eroding inland as a result of wave action<\/p>\n

sea-floor spreading<\/strong>\u00a0 the formation of new oceanic crust by volcanism at a divergent plate boundary<\/p>\n

sector collapse<\/strong>\u00a0 the sudden collapse of a significant part of the flank of a volcano<\/p>\n

sedimentary rock<\/strong>\u00a0 rock that has formed by the lithification of sediments or by the precipitation of ions from water<\/p>\n

sediments<\/strong>\u00a0 unconsolidated (loose) particles of mineral or rock<\/p>\n

seismic<\/strong>\u00a0 pertaining to earthquakes<\/p>\n

seismic moment<\/strong>\u00a0 a measurement of an earthquake\u2019s energy based on longwave vibrations, or on the product of the fault area and displacement<\/p>\n

seismic reflection sounding<\/strong>\u00a0 measurement of the properties of sediments based on detection of sounds generated at surface and reflected from layers beneath the surface<\/p>\n

septae<\/strong>\u00a0 calcareous partitions between the successive living chambers in a cephalopod<\/p>\n

septic system<\/strong>\u00a0 a system constructed to facilitate the dispersion and detoxification of sewage (typically includes a septic tank and a drainage field)<\/p>\n

shaft<\/strong>\u00a0 a vertical opening at a mine<\/p>\n

shale<\/strong>\u00a0 a silt- and clay-rich rock that has evidence of layering<\/p>\n

shatter cone<\/strong>\u00a0 conical nested fractures that result from extraterrestrial impacts. Cones point toward the impact.<\/p>\n

shear force<\/strong>\u00a0 the component of the gravitational force in the direction parallel to a slope<\/p>\n

shear strength<\/strong>\u00a0 the strength of a body of rock or sediment that counteracts the shear force<\/p>\n

shear stress<\/strong>\u00a0 the stress placed on a body of rock or sediment adjacent to a fault<\/p>\n

sheeted dikes<\/strong>\u00a0 a series of near-vertical dykes formed in the vicinity of a spreading ridge when magma from depth flows into fractures formed by extensional forces<\/p>\n

sheet silicate<\/strong>\u00a0 a silicate mineral in which the silica tetrahedra are combined within sheets<\/p>\n

sheetwash<\/strong>\u00a0 overland flow of water, typically related to a heavy precipitation event<\/p>\n

shield\u00a0 <\/strong>a region of ancient (typically Precambrian) crystalline rock (equivalent to a craton)<\/p>\n

shield volcano<\/strong>\u00a0 a low-profile volcano formed primarily from eruptions of low-viscosity mafic magma<\/p>\n

shocked quartz<\/strong>\u00a0 quartz crystals in which the structure has been deformed by sudden, intense pressure. Deformation is visible as parallel lines within the crystal. with damage along parallel plains<\/p>\n

Sial (sialic)<\/strong>\u00a0 an outdated term referring to rock or magma in which silica and aluminum are the predominant components (generally equivalent to felsic)<\/p>\n

silica<\/strong>\u00a0 a form of the mineral quartz (SiO2<\/sub>)<\/p>\n

silica tetrahedron<\/strong>\u00a0 an ion which is a combination of 1 silicon atom and 4 oxygen atoms that form a tetrahedron shape (SiO4<\/sub>4-<\/sup>)<\/p>\n

silicate<\/strong>\u00a0 a mineral that includes silica tetrahedra<\/p>\n

silicon<\/strong>\u00a0 the 14th element<\/p>\n

silicone<\/strong>\u00a0 resin or caulking made from silicon<\/strong>-oxygen chains and various organic molecules<\/p>\n

sill<\/strong>\u00a0 a tabular igneous intrusion (pluton) that is parallel to existing layering in the country rock<\/p>\n

silt<\/strong>\u00a0 sedimentary particles ranging is size from 1\/256th to 1\/16th of a mm<\/p>\n

siltstone<\/strong>\u00a0 a clastic sedimentary rocks consisting predominately of silt-sized particles<\/p>\n

Sima (simatic)<\/strong>\u00a0 an outdated term referring to rock or magma in which silica, magnesium and iron are the predominant components (generally equivalent to mafic)<\/p>\n

skarn<\/strong>\u00a0 the contact metamorphism (and metasomatism) of limestone<\/p>\n

slab pull<\/strong>\u00a0 the concept that at least part of the mechanism of plate motion is the pull of oceanic lithosphere down into the mantle<\/p>\n

slate<\/strong>\u00a0 a fine-grained metamorphic rock that splits easily into sheets<\/p>\n

slaty cleavage<\/strong>\u00a0 the tendency for slate or phyllite to split into sheets (note that this is the only situation in this textbook where the term \u201ccleavage\u201d is applied to a rock as opposed to a mineral)<\/p>\n

slide<\/strong>\u00a0 the downward movement of rock or sediment on a slope as an intact mass<\/p>\n

slump<\/strong>\u00a0 a slide in which the nature of the motion is rotational (typically only develops in unconsolidated sediments)<\/p>\n

smectite<\/strong>\u00a0 a fine-grained sheet silicate mineral that can accept water molecules into interlayer spaces, resulting is swelling<\/p>\n

smelter<\/strong>\u00a0 a refinery at which minerals are processed to produce pure metals<\/p>\n

snow line<\/strong> (frost line)\u00a0 in the context of newly forming planetary systems, the distance beyond a star at which volatile components (e.g., water, carbon dioxide, methane, ammonia etc.) are frozen<\/p>\n

soil horizon<\/strong>\u00a0 a layer, within a well-developed soil, that is physically or chemically different from layers above or below<\/p>\n

solar system<\/strong>\u00a0 a star and the planets surrounding it. Sometimes used specifically for the sun and its planets, and planetary system used for other stars<\/p>\n

solar wind<\/strong>\u00a0 a stream of ionized (charged) particles away from the sun<\/p>\n

solid solution<\/strong>\u00a0 the substitution of one element for another in a mineral (e.g., in Bowen’s reaction series there exists a continuum of plagioclase feldspar where calcium becomes progressively less common, and sodium more so)<\/p>\n

solifluction<\/strong>\u00a0 the flow of water saturated sediment or soil over a stronger and less permeable substrate<\/p>\n

sorting<\/strong>\u00a0 the extent to which the grain size within a sample of sediment is similar.\u00a0 Well-sorted sediments have very similar grain sizes, and poorly-sorted sediments have a variety of grain sizes.<\/p>\n

source rock<\/strong>\u00a0 the sedimentary rock from which petroleum originates prior to its migration into a reservoir rock<\/p>\n

speleothem<\/strong>\u00a0 a cave structure formed when calcium carbonate precipitates (see also stalactite, stalagmite)<\/p>\n

sphericity<\/strong>\u00a0 the extent to which a grain is the same diameter in all dimensions (e.g., more like a sphere, but without implying roundness or smoothness)<\/p>\n

spit<\/strong>\u00a0 a sand or coarser deposit extending from shore out into open water<\/p>\n

spring<\/strong>\u00a0 a flow of groundwater onto the surface<\/p>\n

stack<\/strong>\u00a0 a prominent rocky island that is a remnant of the erosion of a headland<\/p>\n

stage<\/strong>\u00a0 the level of water in a stream<\/p>\n

stalactite<\/strong>\u00a0 a cone-shaped speleothem that is suspended from the roof of a cave<\/p>\n

stalagmite<\/strong>\u00a0 a cone-shaped speleothem that forms on the floor of a cave<\/p>\n

step-pool<\/strong>\u00a0 a characteristic of stream flow in which water flows from one pool to another, typically on a stream with a steep gradient<\/p>\n

stock<\/strong>\u00a0 an irregular pluton with n exposed area less than 100 km2<\/sup>stoping<\/strong>\u00a0 the fracturing and incorporation of fragments of country rock as a magma body moves upward through the crust<\/p>\n

strain<\/strong>\u00a0 the deformation of rock that is subjected to stress<\/p>\n

streak<\/strong>\u00a0 the mark left on a porcelain plate when a mineral sample is ground to a powder by being rubbed across the plate (typically provides a more reliable depiction of the colour than the whole sample)<\/p>\n

stream<\/strong>\u00a0 any body of flowing water<\/p>\n

stress<\/strong> a force applied to a rock (specifically, the force per unit area)<\/p>\n

stress transfer<\/strong> the change in the pattern of stress on a region of rock as a result of an earthquake (typically stress is reduced in the area of a rupture zone, but is increased elsewhere in the vicinity)<\/p>\n

strike<\/strong>\u00a0 the compass direction of a horizontal line on a sloped surface (e.g., bedding plane, fracture etc.)<\/p>\n

strike-slip fault<\/strong>\u00a0 a fault that is characterized by motion that is close to horizontal and parallel to the strike direction of the fault<\/p>\n

subaerial eruption<\/strong>\u00a0 a volcanic eruption that takes place on land<\/p>\n

subaqueous eruption<\/strong>\u00a0 a volcanic eruption that takes place under water<\/p>\n

subducted<\/strong>\u00a0 when part of a plate is forced beneath another plate along a subduction zone<\/p>\n

subduction zone<\/strong>\u00a0 the sloping region along which a tectonic plate descends into the mantle beneath another plate<\/p>\n

subglacial<\/strong>\u00a0 beneath a glacier<\/p>\n

sulphate<\/strong>\u00a0 a mineral in which the anion is SO4<\/sub>2-<\/sup>sulphide<\/strong>\u00a0 a mineral in which the anion is S2-<\/sup>supergroup<\/strong>\u00a0\u00a0 a stratigraphically continuous series of related groups<\/p>\n

superterrane<\/strong>\u00a0 a number of terranes that are contiguous<\/p>\n

supraglacial<\/strong>\u00a0 on the surface of a glacier<\/p>\n

surf zone\u00a0<\/strong> the near-shore zone where waves are breaking into surf<\/p>\n

suture<\/strong>\u00a0 the line on the surface of a cephalopod that marks the boundary between a septum and the outer shell<\/p>\n

swash<\/strong>\u00a0 the upward motion of a wave on a beach (typically takes place at the same angle that the waves are approaching the shore)<\/p>\n

s-wave<\/strong>\u00a0 a seismic body wave that is characterized by deformation of the rock transverse to the direction that the wave is propagating<\/p>\n

symmetrical<\/strong> a fold in which the limbs are at the same angle to the hinge<\/p>\n

syncline<\/strong> a downward fold where the beds are known not to be overturned<\/p>\n

synform<\/strong>\u00a0 a downward fold where it is not known if the beds are overturned<\/p>\n

<\/a>T<\/h2>\n

tabular<\/strong>\u00a0 referring to a structure that is sheet-like (or like a table top). See also dike, sill<\/p>\n

tailings<\/strong>\u00a0 the fine-grained waste rock from a plant used to concentrate ore minerals<\/p>\n

talus slope\u00a0 <\/strong>a sloped deposit of angular rock fragments at the base of a rocky escarpment<\/p>\n

tarn<\/strong>\u00a0 a lake within a rock basin<\/p>\n

tectonic plate<\/strong>\u00a0 a fragment of the lithosphere that moves across the surface of the Earth as a single unit<\/p>\n

tectonic sea level change<\/strong>\u00a0 relative sea level change related to the vertical motion of a crustal block caused by tectonic processes<\/p>\n

tephra<\/strong>\u00a0 fragments of volcanic rock (including volcanic ash) ejected during an explosive eruption<\/p>\n

terminal moraine<\/strong>\u00a0 and end moraine that marks the farthest forward advance of a glacier<\/p>\n

terrane<\/strong>\u00a0 a block of crust that has geological features which are distinctive from neighbouring regions, and is assumed to have been moved from elsewhere by tectonic processes<\/p>\n

terrestrial planet\u00a0 <\/strong>a planet with a rocky mantle and crust, and metallic core (e.g., Earth)<\/p>\n

terrigenous\u00a0<\/strong> referring to sedimentary particles that originated on a continent<\/p>\n

test\u00a0 <\/strong>the shell-like hard parts (either silica or carbonate) of small organisms such as radiolarian and foraminifera<\/p>\n

Theory.<\/strong> A hypothesis that has passed repeated and rigorous testing.<\/span><\/p>\n

thrust fault\u00a0<\/strong> a low angle reverse fault<\/p>\n

till<\/strong>\u00a0 unsorted sediment transported and deposited by glacial ice<\/p>\n

tiltmete<\/strong>r\u00a0 a sensitive instrument used to monitor subtle changes in the tilt of the land, particularly in studies of active volcanoes<\/p>\n

tombolo<\/strong>\u00a0 a sand or coarser deposit connecting an island or rocky prominence to a larger body of land<\/p>\n

traction<\/strong>\u00a0 a force that contributes to the movement of particles situated on a stream bed or desert floor<\/p>\n

transform fault<\/strong>\u00a0 a boundary between two plates that are moving horizontally with respect to each other<\/p>\n

transportation\u00a0 r<\/strong>efers to moving sediments from one location to another<\/p>\n

transported soils<\/strong>\u00a0 soils which form on sediments that have been moved from their original location.\u00a0 The soils themselves have not been transported.<\/p>\n

travertine<\/strong>\u00a0 a deposit of calcium carbonate that forms at springs, hot springs or within limestone caves<\/p>\n

trellis<\/strong>\u00a0 a drainage pattern in which tributaries typically flow parallel to one other but meet at right angles<\/p>\n

trigger<\/strong>\u00a0 an event, such as an earthquake or a heavy rainfall, that starts a mass wasting event<\/p>\n

trough<\/strong>\u00a0 the lowest point of a wave<\/p>\n

truncated spur<\/strong>\u00a0 the steep end of a ridge or ar\u00eate that has been eroded by a main-valley glacier<\/p>\n

tsunami<\/strong>\u00a0 a long-wavelength wave produced by the vertical motion of the floor of the ocean or a large lake, typically related either to an earthquake or a sub-marine mass wasting event<\/p>\n

tufa<\/strong>\u00a0 a form of travertine that is especially porous as it forms around existing vegetative material.<\/p>\n

tuya<\/strong>\u00a0 a flat-topped volcanic hill or mountain that formed when an eruption took place beneath a glacier and the melting led to the formation of a lake that then resulted in the wave-erosion of the top of the volcano<\/p>\n

<\/a>U<\/h2>\n

unconfined aquifer<\/strong>\u00a0 an aquifer that is not overlain by a confining layer<\/p>\n

unconformity<\/strong>\u00a0 a geological boundary at the base of a sedimentary layer<\/p>\n

unconformity-type uranium deposit<\/strong>\u00a0 a uranium deposit that has formed at a nonconformity between sandstone and older rock<\/p>\n

uncompressed density<\/strong>\u00a0 the density of planetary material that it would have it was not compressed by the planets gravitational force<\/p>\n

underground storage tank<\/strong> (UST) an underground tank for storing liquids, most commonly for liquid fuel<\/p>\n

Uniformitarianism.<\/strong> The idea that geological processes today can be used to understand geological processes in the past.<\/span><\/p>\n

unsaturated zone<\/strong>\u00a0 the rock or sediment above the water table<\/p>\n

U-shaped valley<\/strong>\u00a0 a relatively straight valley with a flat bottom and steep sides that has been carved by a valley glacier<\/p>\n

<\/a>V<\/h2>\n

valley glacier<\/strong>\u00a0 a glacier formed in a mountainous region and confined to a valley (same as alpine glacier)<\/p>\n

varve<\/strong>\u00a0 a recognizable layer within sediments that represents a single year of deposition<\/p>\n

vesicular<\/strong>\u00a0 an igneous texture characterized by holes left by gas bubbles<\/p>\n

volcanic glass<\/strong>\u00a0 lava that has cooled within minutes, not allowing time for the formation of crystals<\/p>\n

volcanic-hosted massive sulphide<\/strong>\u00a0 a mineral deposit hosted by volcanic rocks and including zones where most of the rock is made up of sulphide minerals (including ore minerals and pyrite)<\/p>\n

<\/a>W<\/h2>\n

wacke<\/strong>\u00a0 a sandstone with more than 15% clay and silt<\/p>\n

water table<\/strong>\u00a0 the upper surface of the saturated zone in an unconfined aquifer<\/p>\n

wave base<\/strong>\u00a0 the depth of water that is affected by the sub-surface orbital motion of wave action (approximately one-half of the wavelength)<\/p>\n

wave-cut platform<\/strong>\u00a0 a nearly-horizontal bench of rock eroded by waves within the surf zone (equivalent to wave-cut terrace)<\/p>\n

wavelength<\/strong>\u00a0 the distance between the crests of two waves<\/p>\n

weathering<\/strong>\u00a0 a range of processes taking place in the surface environment, through which solid rock is transformed into sediment and ions in solution<\/p>\n

wedging<\/strong>\u00a0 physical (mechanical) weathering processes which involve forcing open cracks in a rock (see also frost wedging, root wedging, salt wedging)<\/p>\n

Western Canada Sedimentary Basin<\/strong>\u00a0 a large basin in the western interior of Canada, east of the Rocky Mountains, extending from the northern United States to the Northwest Territories<\/p>\n

Wisconsin Glaciation<\/strong>\u00a0 the most recent advance of the Pleistocene glaciations, extending from 85 to 11 ka<\/p>\n

<\/a>X<\/h2>\n

xenolith<\/strong> (zee-know-lith) A fragment of country rock incorporated into igneous rock, commonly as a result of stoping<\/p>\n

<\/a>Y<\/h2>\n

youthful stream<\/strong>\u00a0 a stream that is actively down-cutting its valley in an area that has recently been uplifted<\/p>\n

<\/a>Z<\/h2>\n

zone of ablation<\/strong>\u00a0 the part of a glacier, below the equilibrium line, where there is net loss of ice mass due to melting and calving<\/p>\n

zone of accumulation<\/strong>\u00a0 the part of a glacier, above the equilibrium line, where there is net gain of ice mass because not all of the snow that falls each winter is able to melt during the following summer<\/p>\n","protected":false},"author":123,"menu_order":1,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"back-matter-type":[],"contributor":[],"license":[],"class_list":["post-827","back-matter","type-back-matter","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/back-matter\/827","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/back-matter"}],"about":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/types\/back-matter"}],"author":[{"embeddable":true,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/users\/123"}],"version-history":[{"count":3,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/back-matter\/827\/revisions"}],"predecessor-version":[{"id":1424,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/back-matter\/827\/revisions\/1424"}],"metadata":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/back-matter\/827\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/media?parent=827"}],"wp:term":[{"taxonomy":"back-matter-type","embeddable":true,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/back-matter-type?post=827"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/contributor?post=827"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/opentextbc.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/license?post=827"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}