This page gathers the 3,219 dictionary entries belonging to the domain “Geography”, as labelled by Wiktionary. Each word leads to its full entry: definitions, etymology, pronunciation, examples. Page 21 of 32: from “oolith” to “paramorph”.
- oolith noun A spherical granule of which oolite is composed, formed by concentric accretion of thin layers of a mineral (usually calcium carbonate…
- oolitic adj Made up of, or containing oolites
- ooze noun A pelagic marine sediment containing a significant amount of the microscopic remains of either calcareous or siliceous planktonic debris…
- opal noun A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity, of the chemical formula SiO₂·nH₂O.
- opal pineapple noun Alternative form of pineapple opal.
- opaline noun Any of several minerals resembling opal, including a variety of yellow chalcedony.
- opalite noun Opal; some variety of it; an artificial mineral resembling it.
- ophiolite noun An assemblage of mafic and ultramafic rock fragments of the ocean lithosphere that has been tectonically moved onto a continental margin or…
- ophite noun Any of various rocks having snake-like markings, such as a mottled greenish porphyry.
- ophitic adj Having crystals of feldspar interspersed with plates of augite.
- ophthalmite noun A migmatite that is characterized by the presence of concentric or lenticular aggregates of newly formed minerals that reflect…
- optic axis noun The direction in which a ray of light passing through a crystal does not suffer double refraction.
- optimum noun Any long period of time marked by a persistently warm climate; a climatic optimum.
- orbicule noun An inclusion in an igneous rock
- Ordovician adj Of a geologic period within the Paleozoic era; comprises lower, middle and upper epochs from about 488 to 443 million years ago.
- ore belt noun A region containing a group of ore deposits that were formed by a specific geological event and have a favorable geological environment.
- organogenic adj Describing any rock ultimately derived from living organisms
- origin noun An arbitrary point on Earth's surface, chosen as the zero for a system of coordinates.
- orocline noun A mountain belt whose process of deformation is visible.
- orograph noun A machine for use in making topographical maps, operated by being pushed across country, and recording distances and elevations.
- orography noun The scientific study, or a physical description of mountains.
- orometric adj Pertaining to orometry. Pertaining to measuring mountains.
- orpheite noun A trigonal-hexagonal scalenohedral mineral containing aluminum, hydrogen, lead, oxygen, phosphorus, and sulfur.
- orschallite noun A trigonal-hexagonal scalenohedral colorless mineral containing calcium, hydrogen, oxygen, and sulfur.
- ortho- prefix Igneous.
- orthoamphibolite noun Metamorphic rock composed mostly of amphibole, plagioclase, with lesser amounts of epidote, zoisite, chlorite, quartz, titanite, and…
- orthoclase noun Potassium aluminum silicate, KAlSi₃O₈, a common feldspar of igneous, plutonic, and metamorphic rocks. Orthoclase is the main feldspar of…
- orthoericssonite noun An orthorhombic-dipyramidal reddish black mineral containing barium, hydrogen, iron, manganese, oxygen, and silicon.
- orthogeosyncline noun A linear geosynclinal belt lying between continental and oceanic cratons, and having internal volcanic belts (eugeosynclinal) and external…
- orthographical adj Orthographic.
- orthometric adj Being corrected for the curvature of the Earth.
- orthophotomap noun A map in the form of an orthophotomosaic.
- orthorhombic pyroxene noun Any of a group of minerals having the general formula XYSi₂O₆ in which X is iron or magnesium and Y is iron or manganese.
- orthoserpierite noun An orthorhombic-pyramidal pale blue green mineral containing calcium, copper, hydrogen, oxygen, sulfur, and zinc.
- orthosilicate noun Any silicate mineral, such as garnet or olivine, in which the SiO₄ tetrahedra do not share oxygen atoms with each other.
- orthowalpurgite noun An orthorhombic-dipyramidal pale yellow mineral containing arsenic, bismuth, hydrogen, oxygen, and uranium.
- orvietite noun A mineral consisting of a mixture of plagioclase and sanidine with smaller amounts of leucite and augite, etc.
- osarizawaite noun A greenish-yellow mineral with the chemical formula PbCuAl₂(SO₄)₂(OH)₆, having rhombohedral crystals.
- oursinite noun An orthorhombic pale yellow mineral containing cobalt, hydrogen, magnesium, oxygen, silicon, and uranium.
- outcrop verb To come out to the surface of the ground.
- outer core noun The part of the Earth between the mantle and inner core, responsible for generating the planet's magnetic field.
- outlier noun A part of a formation separated from the rest of the formation by erosion.
- ovamboite noun An isometric-hextetrahedral gray mineral containing arsenic, copper, gallium, germanium, iron, molybdenum, sulfur, tin, tungsten, vanadium…
- overbank adj Describing sediments deposited on a floodplain from suspensions in floodwaters
- overbreak noun Rock or earth excavated beyond the planned extent; caving in of material near the edge of an excavation.
- overburden noun The rock and subsoil that lies above a mineral deposit such as a coal seam, or any other underground feature.
- overfold noun A fold whereby the strata are forced through an angle of more than 90 degrees, so that younger strata lie below older ones.
- overplate verb To move on top of and cover another tectonic plate.
- overpost noun An overlap of two graphic elements.
- overprint noun The set of petrological, structural, and/or mineralogical characteristics superimposed onto rock by the action of geological processes over…
- overshift noun The amount of displacement in the layers in a crystal lattice that places the layers too far apart for molecular bonding.
- overthrust noun A form of thrust fault from beneath a hanging wall of rock.
- owyheeite noun An orthorhombic-dipyramidal gray-white mineral containing antimony, bismuth, lead, silver, and sulfur.
- Oxfordian adj Relating to the Oxfordian age or stage.
- oxonian adj Containing oxygen.
- ozarkite noun Thomsonite, a mineral series of the zeolite group.
- P wave noun A longitudinal compressional wave produced by an earthquake.
- paar noun A hypothesized shifting of four geologic blocks: northeast Africa west of Red Sea and north of the Ethiopian valley, the Arabian Peninsula…
- paceite noun A tetragonal-dipyramidal dark blue mineral containing calcium, carbon, copper, hydrogen, and oxygen.
- pachnolite noun A monoclinic-prismatic mineral containing aluminum, calcium, fluorine, hydrogen, oxygen, and sodium.
- paderaite noun A monoclinic-prismatic creamy white mineral containing bismuth, copper, lead, silver, sulfur, and tellurium.
- pahasapaite noun An isometric-tetartoidal mineral containing beryllium, calcium, hydrogen, lithium, oxygen, phosphorus, potassium, and sodium.
- painite noun A very rare orange-red borate mineral consisting mostly of calcium, zirconium, boron, aluminium, and oxygen.
- palaeoscience noun Any scientific discipline that studies the geologic past; especially a division of a study that normally focuses on the present geological…
- palenzonaite noun An isometric-hexoctahedral wine red mineral containing arsenic, calcium, manganese, oxygen, silicon, sodium, and vanadium.
- Paleoarchean adj Of a geologic era within the Archaean eon from about 3600 to 3200 million years ago; the first aerobic bacteria appeared at this time.
- paleofauna noun The animals that were alive in a particular period of geological history, especially those known only as fossils.
- Paleogene adj Of a geologic period within the Cenozoic era; comprises the Paleocene, Eocene and Oligocene epochs from about 65 to 23 million years ago.
- paleolatitude noun The former latitude of a particular geologic formation at a time in the geologic past, often specifically the time of formation
- paleolongitude noun The former longitude of a particular geologic formation at a time in the geologic past, often specifically the time of formation
- paleomagnetism noun The study of the strength and direction of the Earth's magnetic field as it has changed over geologic time.
- paleomicrocontinent noun A small fragment of continental crust that existed as an independent or semi-independent landmass in the geological past, rather than being…
- paleosecular adj Relating to long-term non-periodic irregularities, especially in magnetic field, in the geologic past
- paleoseismology noun The study of ancient rocks and sediments for evidence of seismic events, such as earthquakes and tsunamis, from times before records were…
- Paleozoic adj Of a geologic era within the Phanerozoic eon that comprises the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian periods…
- palermoite noun An orthorhombic-dipyramidal mineral containing aluminum, calcium, hydrogen, lithium, oxygen, phosphorus, sodium, and strontium.
- palimpsest noun Geological features thought to be related to features or effects below the surface.
- palingenesis noun The regeneration of magma by the melting of metamorphic rocks.
- palinspastic adj Showing the previous location of geological features, correcting for any intervening crustal movements.
- palladian adj Containing tetravalent palladium.
- palsa noun A hummock rising out of a bog with a core of ice; similar in appearance to a pingo but due to different structure palsas cannot grow as big…
- pan noun A pond or lake, considered as the expanse of land upon which the water sits.
- panasqueiraite noun A monoclinic-prismatic mineral containing calcium, fluorine, hydrogen, magnesium, oxygen, and phosphorus.
- panethite noun A monoclinic-prismatic brownish yellow mineral containing calcium, iron, magnesium, manganese, oxygen, phosphorus, potassium, and sodium.
- panhandle noun An area within a nation or subnational division that appears to stick out or project when viewed on a map; an especially elongated salient.
- papagoite noun A monoclinic-prismatic light blue mineral containing aluminum, calcium, copper, hydrogen, oxygen, and silicon.
- paper clay noun Synonym of kaolin; also similarly uniform light-coloured clay composed of fine particles.
- paper town noun A nonexistent town included on a map in order to identify cases of plagiarism by others.
- parablepsis noun A circumstance in which a scribe miscopies text due to inadvertently looking to the side while copying, or accidentally skips over some of…
- paracelsian noun A natural polymorph of celsian.
- paraconformity noun A type of unconformity in which strata are parallel; there is no apparent erosion and the unconformity surface resembles a simple bedding…
- paraffin noun Any member of the alkane hydrocarbons.
- paragenesis noun An ordered chronological sequence of mineral formations.
- paragenic adj Pertaining to the sequence and conditions under which minerals or mineral assemblages form in relation to one another.
- parageosyncline noun A geosyncline within or adjacent to a craton and usually less elongated, shallower, and less persistent than an orthogeosyncline.
- paragon noun A flawless diamond of at least 100 carats.
- parakhinite noun A hexagonal-trapezohedral dark green mineral containing copper, hydrogen, lead, oxygen, and tellurium.
- parallel noun A line of latitude.
- paramendozavilite noun A monoclinic mineral containing aluminum, hydrogen, iron, molybdenum, oxygen, phosphorus, and sodium.
- paramorph noun A kind of pseudomorph in which there has been a change of physical characteristics without alteration of chemical composition, as in the…