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Earth

Historical geology

Abrasion (geology)

Process of wearing down or wearing away of rocks by the hard particles carried by rivers, glaciers, wind and waves

Absolute dating

Process of determining an age on a specified chronology in archaeology and geology

Flat area on the deep ocean floor

A rock that is among the oldest known crustal fragments on Earth

Accretionary wedge

The sediments accreted onto the non-subducting tectonic plate at a convergent plate boundary

Aeolian processes

Processes due to wind activity

A major tectonic plate underlying Africa west of the East African Rift

Smaller earthquake which follows a larger one in the same area

Scientific dating of the age of the Earth

The increase in land elevation due of the deposition of sediment

Mineral, Na-feldspar, Na-silicate, tectosilicate

Algoman orogeny

Late Archaean episode of mountain building in what is now North America

A fan- or cone-shaped deposit of sediment crossed and built up by streams

Loose soil or sediment that is eroded and redeposited in a non-marine setting

Alvarez hypothesis

Asteroid impact hypothesis as cause of the Cretaceous–Paleogene extinction

Group of inosilicate minerals

A metamorphic rock containing mainly amphibole and plagioclase

Nesosilicate mineral

Ongoing mountain-forming process in South America

Type of volcanic rock

Calcium-rich feldspar mineral

Antarctic plate

A tectonic plate containing the continent of Antarctica and extending outward under the surrounding oceans

Proposed geologic epoch for the timespan of significant human impact on the Earth

In geology, an anticline is a type of fold that is an arch-like shape

Mineral group, calcium phosphate

A minor tectonic plate consisting mostly of the Arabian Peninsula, extending northward to Mesopotamia and the Levant

Calcium carbonate polymorph

Geologic eon, 4031–2500 million years ago

Chain, cluster or collection of islands, or sometimes a sea containing a small number of scattered islands

Argon–argon dating

Radiometric dating method

Artificial island

An island constructed by people

Carcinogenic fibrous silicate mineral

The highly viscous, mechanically weak and ductile region of Earth's mantle

Ring-shaped coral reef

Pyroxene mineral

Submarine features associated with island arcs and subduction zones

A type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded

Late-Proterozoic to early-Palaeozoic continent

Banded iron formation

Layered iron-rich sedimentary rock

Bar (river morphology)

An elevated region of sediment in a river that has been deposited by the flow

Coastal dune landform that forms by wave and tidal action parallel to the mainland coast

Sulfate mineral

A magnesium- and iron-rich extrusive igneous rock

Basement (geology)

Metamorphic or igneous rocks below a sedimentary platform or cover

Large igneous rock intrusion

Sedimentary rock rich in aluminium

Recessed, coastal body of water connected to an ocean or lake

Area of loose particles at the edge of the sea or other body of water

Stratigraphic subdivison

Particles in a flowing fluid that are transported along the bed

Result of bed material being moved by fluid flow

Belt Supergroup

Group of Mesoproterozoic sedimentary rocks

Gemstone: beryllium aluminium cyclosilicate

Biogeochemistry

The study of chemical cycles of the earth that are either driven by or influence biological activity

Biostratigraphy

Stratigraphy which assigns ages of rock strata by using fossils

Group of minerals

Reworking of soils and sediments by organisms.

Rank of biostratigraphic unit

A metavolcanic rock that forms by the metamorphism of basalt and rocks with similar composition

Type of wetland that accumulates peat due to incomplete decomposition of plant matter

Structures in rock caused by extension

Natural rock fragment larger than 25.6 centimetres in diameter

Bowen's reaction series

Order of crystallization of minerals in magma

Rock composed of broken fragments cemented by a matrix

Brittle–ductile transition zone

The strongest part of the Earth's crust

Isolated hill with steep, often vertical sides and a small, relatively flat top

Law in rheology

Carbonate mineral and polymorph of calcium carbonate

Cauldron-like volcanic feature formed by the emptying of a magma chamber

First period of the Paleozoic Era, 541-485 million years ago

Cambrian explosion

Major evolutionary diversification of animal life during the Cambrian period, 541 million years ago

Deep ravine between cliffs

Cape (geography)

A large headland extending into a body of water, usually the sea

Biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere

Carbonate mineral

Minerals in which CO3 and NO3 are the main anion

Class of sedimentary rock

Fifth period of the Paleozoic Era

Caribbean plate

A mostly oceanic tectonic plate including part of Central America and the Caribbean Sea

Rock formed by fracturing and comminution during faulting

Natural void under the Earth's surface

Cementation (geology)

Process of chemical precipitation bonding sedimentary grains

Natural pit or sinkhole that exposes groundwater underneath

Third era of the Phanerozoic Eon 66 million years ago to present

Central Asian Orogenic Belt

Phanerozoic accretionary orogen

Copper iron sulfide mineral

Characters of the Final Fantasy VII series

Phyllosilicates: non-swelling 2:1 clay (TOT) whose interlayer is occupied by a brucite, Mg(OH)2, bridge

Chronostratigraphy

Study of relative time relations and ages of rock layers

A steep conical hill of loose pyroclastic fragments around a volcanic vent

Red mercury sulfide mineral

An amphitheatre-like valley formed by glacial erosion

Sedimentary rocks made of mineral or rock fragments

A finely-grained natural rock or soil containing mainly clay minerals

Hydrous aluminium phyllosilicates

Cleavage (geology)

Structural geology

A form of coast where the action of marine waves has formed steep cliffs that may or may not be precipitous

Closure temperature

Temperature threshold above which the age of an isotopic system is reset

The fringe of land at the edge of a large body of water

The fringe of land at the edge of a large body of water

Cobble (geology)

A rock larger than a pebble and smaller than a boulder

Young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America

Columbia River Basalt Group

Continental flood basalt province in the Western United States

Community-Led Infrastructure Finance Facility

UK and Swedish finance facility

Complex volcano

Landform of more than one related volcanic centre

Computational geophysics

Conglomerate (geology)

A coarse-grained clastic sedimentary rock with mainly rounded to subangular clasts

Contact (geology)

Boundary between geologic units

Very large landmass identified by convention

Continental crust

Layer of rock that forms the continents and continental shelves

Continental drift

The movement of the Earth's continents relative to each other

Continental fragment

Part of a continent broken from its main mass

Continental margin

Zone of the ocean floor that separates the thin oceanic crust from thick continental crust

Continental rise

An underwater feature connecting the continental slope and the abyssal plain

Continental shelf

A portion of a continent that is submerged under an area of relatively shallow water known as a shelf sea

Convergent boundary

Region of active deformation between colliding tectonic plates

Island formed from coral and associated material

Outcrop of rock in the sea formed by the growth and deposit of stony coral skeletons

Cylindrical section of a naturally occurring substance, usually obtained by drilling into it with special drills

Old and stable part of the continental lithosphere

Cratonic sequence

A very large-scale lithostratographic sequence that covers a complete marine transgressive-regressive cycle across a craton

Texture of metamorphic rock by deformation

Third and last period of the Mesozoic Era 145-66 million years ago

Cretaceous–Paleogene boundary

Geological signature marking the boundary between the end of the Cretaceous Period and the beginning of the Paleogene Period

Cretaceous–Paleogene extinction event

Mass extinction event

Sedimentary rock strata at differing angles.

Crust (geology)

The outermost solid shell of a rocky planet, dwarf planet, or natural satellite

Mineral discovered and named after its place of discovery, Cummington, Massachusetts

Outside bank of a water channel, which is continually undergoing erosion

Volcanic rock intermediate in composition between andesite and rhyolite

A large igneous province located on the Deccan Plateau

Geological feature

Degradation (geology)

Lowering of a fluvial surface, such as a stream bed or floodplain, through erosional processes

Deposition (geology)

Geological process in which sediments, soil and rocks are added to a landform or landmass

Depression (geology)

Landform sunken or depressed below the surrounding area

Area of land where little precipitation occurs

Detachment fault

Geological term associated with large displacements

Detrital zircon geochronology

Science of analyzing the age of zircons

Fourth period of the Paleozoic Era 419-359 million years ago

Physico-chemical changes in sediments occurring after their deposition

A type of geologic intrusion in which a more mobile and ductily deformable material is forced into brittle overlying rocks

A sheet of rock that is formed in a fracture of a pre-existing rock body

Pyroxene mineral

Intermediate intrusive igneous rock composed principally of plagioclase feldspar

Divergent boundary

Linear feature that exists between two tectonic plates that are moving away from each other

Dolomite (rock)

Sedimentary carbonate rock that contains a high percentage of the mineral dolomite

Slow, downward progression of rock and soil down a low grade slope

Extended period of deficiency in a region's water supply

Ductility (Earth science)

Ancient stage of Earth and its life

Earth ellipsoid

Ellipsoid of rotation that approximates the figure of the Earth

Shaking of the surface of the earth caused by a sudden release of energy in the crust

Earthquake forecasting

A branch of seismology concerned with the probabilistic assessment of earthquake seismic hazard

Earthquake prediction

Branch of geophysics, primarily seismology

Earth's inner core

Innermost part of Earth, a solid ball of iron-nickel alloy

Earth's internal heat budget

Accounting of the energy flows at and below the planet's crust

Earth's magnetic field

Magnetic field that extends from the Earth’s outer and inner core to where it meets the solar wind

Earth's outer core

Fluid layer composed of mostly iron and nickel between Earth's solid inner core and its mantle

Third and last period of the Neoproterozoic Era

Green gemstone, a beryl variety

Pyroxene: magnesium-iron silicate with MgSiO3 and FeSiO3 end-members

Second epoch of the Paleogene period

National chain of stores in Ukraine that specializes in home improvement and gardening.

Sorosilicate mineral

Equatorial bulge

Outward bulge around a planet's equator due to its rotation

Processes which remove soil and rock from one place on the Earth's crust, then transport it to another location where it is deposited

Steep slope or cliff separating two relatively level regions

Long, winding ridge of stratified sand and gravel associated with former glaciers

A tectonic plate which includes most of the continent of Eurasia

A water-soluble mineral sediment formed by evaporation from an aqueous solution

Extinction Event

Topics referred to by the same term

Igneous rock formed when magma emerges above the Earth's surface before cooling

Fabric (geology)

Spatial and geometric configuration of all the elements that make up a rock

Manifestation of character, reflecting conditions of origin of rock strata

An ancient oceanic plate that has mostly subducted under the west coast of the North American Plate

Fault (geology)

Fracture or discontinuity in rock across which there has been displacement

Very large block of rock

Fault mechanics

A field of study that investigates the behavior of geologic faults

Olivine, nesosilicate mineral

A group of rock-forming tectosilicate minerals

Fen (disambiguation)

Topics referred to by the same term

Figure of the Earth

Size and shape used to model the Earth for geodesy

A long, narrow inlet with steep sides or cliffs, created by glacial activity

Shoreline where the land descends gradually into the sea

Archaic conception of Earth's shape as a plane or disk

The result of a very large volume eruption of basalt lava

Land adjacent to a river which is flooded during periods of high discharge

Mineral form of calcium fluoride

Focal mechanism

Process that generates seismic waves in an earthquake

Stack of originally planar surfaces

Mountains formed by compressive crumpling of the layers of rock

Foliation (geology)

Repetitive layering in metamorphic rocks

The region between an oceanic trench and the associated volcanic arc

A structural basin that develops adjacent and parallel to a mountain belt

Forensic geophysics

Use of geophysics tools in forensic science

Earthquake that occurs before a mainshock but is of lower magnitude

Lobby group in the United Kingdom

Olivine, nesosilicate mineral

Fracture (geology)

Geologic structure

A coarse-grained mafic intrusive rock

Natural mineral form of lead sulfide

Mineral, semi-precious stone

Gemstone (disambiguation)

Topics referred to by the same term

Geochemical cycle

Pathway that chemical elements take in the surface and crust of the Earth

Science that applies chemistry to analyze geological systems

Science of determining the age of rocks, sediments and fossils

Science of measuring the shape, orientation, and gravity of Earth

Study of dynamics of the Earth

Geologic province

A spatial entity with common geologic attributes

Geologic record

Entirety of the layers of rock strata

Geologic time scale

System that relates geological strata to time

Geological formation

The fundamental unit of lithostratigraphy

Geological hazard

Geological state that may lead to widespread damage or risk

Geological history of Earth

The sequence of major geological events in Earth's past

Geological history of oxygen

Timeline of the development of free oxygen in the Earth's seas and atmosphere

Study of the composition, structure, physical properties, and history of Earth's components and processes

Geology of the Himalayas

Origins and structure of the mountain range

Geomagnetic pole

The poles of a dipole approximation to the Earth's field

Geomagnetic reversal

Reversal of direction of Earth's magnetic field

Mathematical methods for geophysics

The scientific study of landforms and the processes that shape them

Geophysical fluid dynamics

The fluid dynamics of naturally occurring flows, such as lava flows, oceans, and planetary atmospheres, on Earth and other planets

Physics of the Earth and its vicinity

Geothermal gradient

Rate of temperature increase with depth in Earth's interior

Natural explosive eruption of hot water

Glacial landform

Landform created by the action of glaciers

A common high-grade metamorphic rock

Neoproterozoic to Carboniferous supercontinent

Type of layering in sediment or sedimentary rock

Diameter of individual grains of sediment, or of lithified particles in clastic rocks

Common type of intrusive, felsic, igneous rock with granular structure

Type of coarse grained intrusive igneous rock

A class of high-grade medium to coarse grained metamorphic rocks

Area with vegetation dominated by grasses

Mix of crumbled stones: grain size range between 2 – 63 mm according to ISO 14688

Measurement of the strength of a gravitational field

Gravity of Earth

Acceleration that the Earth imparts to objects on or near its surface

Great Oxidation Event

Paleoproterozoic surge in atmospheric oxygen

Metamorphic rock formed in temperatures of 300–450 °C and pressures of 2–10 hPa, with an abundance of green minerals (e.g. chlorite, serpentine, epidote) and platy minerals (muscovite, serpentine)

Greenstone belt

Zone of variably metamorphosed rocks occurring in Archaean and Proterozoic cratons

A hard, dark sandstone with poorly sorted angular grains in a compact, clay-fine matrix

Group (stratigraphy)

A group of geologic formations

Landform created by running water eroding sharply into soil

Soft calcium sulfate mineral

First eon of geological time, beginning with the formation of the Earth about 4.6 billion years ago

Nickel–Strunz 9 ed mineral class number 3

Mineral form of sodium chloride

Volcanic hotspot located near the Hawaiian Islands, in the northern Pacific Ocean

Australian television series

Shrubland habitat

Pyroxene mineral

Common iron oxide mineral

Mountainous region or elevated mountainous plateau

Landform that extends above the surrounding terrain

Hirnantian glaciation

Glaciation occurred during the Paleozoic from 450 Ma to 420 Ma

Historical geology

The study of the geological history of Earth

History of Earth

The development of planet Earth from its formation to the present day

Current geological epoch, covering the last 11,700 years

A complex inosilicate series of minerals

Series of contact metamorphic rocks that have been baked and indurated by the heat of intrusive igneous masses.

Horst and graben

Topography consisting of alternating raised and lowered fault blocks

Hotspot (geology)

Volcanic regions thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle

Geological feature

Hummocky cross-stratification

Sedimentary structure found in sandstones

Organic matter in soils resulting from decay of plant and animal materials

Huronian glaciation

Severe glaciation during the Paleoproterozoic era

Hydrothermal vent

A fissure in a planet's surface from which geothermally heated water issues

Ocean that existed in the late Neoproterozoic and early Paleozoic eras

Period of long-term reduction in temperature of Earth's surface and atmosphere

Igneous differentiation

Processes by which magmas undergo bulk chemical change during the partial melting process, cooling, emplacement, or eruption

Rock formed through the cooling and solidification of magma or lava

Titanium-iron oxide mineral

Circular depression on a solid astronomical body formed by a hypervelocity impact of a smaller object

Indo-Australian plate

A major tectonic plate formed by the fusion of the Indian and Australian plates

Internal structure of Earth

Inner structure of planet Earth, consisting of several concentric spherical layers

Magmatic rock formed below the surface

Magmatic rock formed below the surface

Sedimentary rock

Very small island

State of gravitational equilibrium between Earth's crust and mantle

Isotope geochemistry

Subfield of geology focused on the study of natural variations in the relative abundances of isotopes of various elements

Narrow strip of land connecting two larger land areas

Ornamental stone, commonly green

Joint (geology)

Geological term for a type of fracture in rock

Juan de Fuca plate

A small tectonic plate in the eastern North Pacific

An impassable dense forest (typically tropical)

Second period of the Mesozoic era

Radiometric dating method

Topography from dissolved soluble rocks

An ultramafic mantle-derived volcanic rock

Aluminosilicate mineral

A shallow body of water separated from a larger body of water by barrier islands or reefs

Violent type of mudflow or debris flow from a volcano

Island located in a lake

Lamination (geology)

Layering structure in sedimentary rocks usually less than 1 cm in thickness

Denial of Service attack

Land reclamation

Creating new land from oceans, seas, riverbeds, or lakes

Feature of the solid surface of a planetary body

Type of natural disasters involving ground movements, often caused by slope instability triggered by specific event

Metamorphic rock containing lazurite, prized for its intense blue color

Laramide orogeny

Period of mountain building in North America

Large igneous province

Huge regional accumulation of igneous rocks

Last Glacial Maximum

Circa 24,000–16,000 BCE; most recent era when ice sheets were at their greatest extent

Last Glacial Period

Period of major glaciations of the northern hemisphere (115,000–12,000 years ago)

Late Devonian extinction

One of the five most severe extinction events in the history of the Earth's biota

Late Heavy Bombardment

Interval when a disproportionately large number of asteroids are theorised to have collided with the inner planets

Late Ordovician mass extinction

Mass extinction event at the end of the Ordovician period and the beginning of the Silurian period in the Paleozoic era, around 444 million years ago

Late Paleozoic icehouse

Northern supercontinent that formed part of the Pangaea supercontinent

Northern supercontinent that formed part of the Pangaea supercontinent

A large continental craton that forms the ancient geological core of the North American continent

Molten rock expelled by a volcano during an eruption

Large, mostly flat area of lava flows

Natural conduit through which lava flows beneath the solid surface

Law of superposition

In undeformed stratigraphic sequences, the oldest strata will be at the bottom of the sequence

Leaching (pedology)

The removal of soluble materials from one zone in soil to another via water movement in the profile

Sedimentary rocks made of calcium carbonate

Lineation (geology)

A descriptive and nongenetic term for any kind of linear structure within or on a rock

List of index fossils

Fossils used to define and identity geologic periods

The rigid, outermost shell of a terrestrial-type planet or natural satellite that is defined by its rigid mechanical properties

Lithostratigraphy

Method of establishing stratigraphical units

Local regression

Moving average and polynomial regression method for smoothing data

Type of seismic wave

The region from 660 to 2900 km below Earth's surface

Low-relief volcanic crater

Natural material found beneath the surface of Earth

Accumulation of molten rock within the Earth's crust

Magnetic anomaly

Local variation in the Earth's magnetic field

Iron ore mineral

Magnetostratigraphy

Method of dating sedimentary and volcanic rocks

A shrub or small tree that grows in coastal saline or brackish water

Mantle (geology)

Part of the interior of the planet Earth

Mantle convection

The slow moving motion of Earth's solid mantle caused by convection currents carrying heat from the planet's interior to its surface

An upwelling of abnormally hot rock within the Earth's mantle

Non-foliated, metamorphic rock, commonly used for sculpture and as a building material

Marine regression

A geological process of areas of submerged seafloor being exposed above the sea level.

Marine transgression

Geologic event in which sea level rises relative to the land

Marinoan glaciation

A period of worldwide glaciation during the Cryogenian period.

Wetland that is dominated by herbaceous rather than woody plant species

Movement of rock or soil down slopes

Open habitat vegetated primarily by non-woody plants

Sinuous bend in a series in the channel of a river

Megathrust earthquake

Type of earthquake at convergent plate boundaries

Elevated area of land with a flat top and sides that are usually steep cliffs

Mesoproterozoic

Second era of the Proterozoic Eon

Second era of the Phanerozoic Eon

Metamorphic reaction

Chemical reaction that takes place during the geological process of metamorphism

Metamorphic rock

Rock that was subjected to heat and pressure

Solid debris from outer space that hits a planetary surface

Group of phyllosilicate minerals

Feldspar, tectosilicate mineral

Mid-ocean ridge

Basaltic underwater mountain system formed by plate tectonic spreading

A mixture of metamorphic rock and igneous rock

Element or chemical compound that is normally crystalline formed as a result of geological processes

Element or chemical compound that is normally crystalline formed as a result of geological processes

Mineral physics

The science of materials that compose the interior of planets

Scientific study of minerals and mineralised artifacts

First epoch of the Neogene Period

Mohorovičić discontinuity

Boundary between the Earth's crust and the mantle

Moment magnitude scale

Measure of earthquake size, in terms of the energy released

Monazite geochronology

Dating technique to study geological history using the mineral monazite

Type of habitat found in upland areas with (sometimes marshy) poor acid soil and overgrown with low vegetation

Glacially formed accumulation of debris

A large landform that rises fairly steeply above the surrounding land over a limited area

Route through a mountain range or over a ridge

A geographic area containing several geologically related mountains

Mixture of water and any combination of soil, silt, and clay

Sedimentary feature resulting from the drying of a clay-rich sediment

Coastal wetlands where sediments have been deposited by tides or rivers

Class of fine grained siliciclastic sedimentary rocks

True mica, phyllosilicate mineral; polytypes: 1M, 2A, 2M2, 3T

Fine-grained, compact metamorphic rock produced by dynamic recrystallization of the constituent minerals

Mineral (as opposed to the chemical element)

Native element mineral

Elements that occur in nature as minerals in uncombined form

Natural disaster

Type of adverse event

Natural resource

Resources that exist without actions of humankind

Oceanic tectonic plate in the eastern Pacific Ocean basin

Near-surface geophysics

Geophysics of first tens of meters below surface

Second geologic period in the Cenozoic Era 23–2.6 million years ago

Third and last era of the Proterozoic Eon

North American plate

Large tectonic plate including most of North America, Greenland and part of Siberia.

North magnetic pole

Wandering point on the Northern Hemisphere

Fertile area in a desert environment

Naturally occurring volcanic glass

Large geologic basins that are below sea level

The uppermost layer of the oceanic portion of a tectonic plate

Long and narrow depressions of the sea floor

Organic-rich fine-grained sedimentary rock containing kerogen

Third epoch of the Paleogene period

Magnesium iron silicate solid solution series mineral

Sedimentary rock formed from ooids

Second period of the Paleozoic Era

Rock with valuable metals, minerals and elements

Organic geochemistry

Study of the impacts and processes that organisms have had on the Earth

The formation of mountain ranges

Tectosilicate mineral found in igneous rock

Biogeochemical cycle of oxygen

Longitudinal seismic wave

An oceanic tectonic plate under the Pacific Ocean

First epoch of the Paleogene Period

Paleocene–Eocene Thermal Maximum

Rapid (in geological terms) global warming, profound changes in ecosystems, and major perturbations in the carbon cycle which started about 55.0 million years ago

Paleoclimatology

Study of changes in ancient climate

A distinct area of continental crust that existed as a major landmass in the geological past

First period of the Cenozoic Era 66-23 million years ago

Study of Earth's magnetic field in past

Paleoproterozoic

First era of the Proterozoic Eon

Paleo-Tethys Ocean

An ocean on the margin of Gondwana between the Middle Cambrian and Late Triassic

Paleothermometer

Study of ancient temperatures

First era of the Phanerozoic Eon 541-252 million years ago

PANGAEA (data library)

Repository and publisher for data from earth system research (georeferenced)

Hypothesized Neoproterozoic supercontinent from the end of the Precambrian

Prehistoric superocean that surrounded Pangaea

Concept of sequence stratigraphy

Partial melting

Partial melting occurs when only a portion of a solid is melted. For mixed substances, such as a rock containing several different minerals or a mineral that displays solid solution, this melt can be different from the bulk composition of the solid.

The transition between oceanic and continental lithosphere that is not an active plate margin

Sea level variations over geological time scales

Accumulation of partially decayed vegetation

Wetland terrain without forest cover, dominated by living, peat-forming plants

Pebble (disambiguation)

Topics referred to by the same term

The study of soils in their natural environment

The outermost layer of the Earth that is composed of soil and subject to soil formation processes

Pelagic red clay

Slow accumulating oceanic sediment with low biogenic constituents

Pelagic sediment

Fine-grained sediment that accumulates on the floor of the open ocean

Geographical feature

A coarse-grained ultramafic igneous rock

Sixth and last period of the Paleozoic Era 299–252 million years ago

Permian–Triassic extinction event

Earth's most severe extinction event

The branch of geology that studies the origin, composition, distribution and structure of rocks

Fourth and current eon of the geological timescale

Philippine Sea plate

Oceanic tectonic plate to the east of the Philippines

Phosphate mineral

Nickel–Strunz 9 ed mineral class number 8 (isolated tetrahedral units, mainly)

Foliated metamorphic rock

Physical geodesy

The study of the physical properties of the Earth's gravity field

Pyroxene mineral

Type of feldspar

Expanse of land which is mostly flat and treeless

Plate tectonics

Movement of the Earth's lithosphere

First epoch of the Quaternary Period

Second epoch of the Neogene period

A depositional feature of alluvium that accumulates on the inside bend of streams and rivers below the slip-off slope

Ratio of void volume and total volume of a porous material

Ecosystems considered part of the temperate grasslands, savannas, and shrublands biome

The earliest part of Earth's history: 4600–541 million years ago

Primordial nuclide

Nuclides predating the Earth's formation (found on Earth)

Prominent mass of land that overlooks lower-lying land or a body of water

Third eon of the geologic timescale, last eon of the Precambrian Supereon

Pull-apart basin

A structural basin where two overlapping faults or a fault bend creates an area of crustal extension which causes the basin to subside

Light coloured highly vesicular volcanic rock

Iron (II) disulfide mineral

Pyroclastic flow

Fast-moving current of hot gas and volcanic matter that moves away from a volcano

Group of inosilicate minerals with single chains of silica tetrahedra

Mineral made of silicon and oxygen.

Hard, non-foliated metamorphic rock which was originally pure quartz sandstone

Third and current period of the Cenozoic Era, from 2.58 million years ago to the present

Quaternary glaciation

Series of alternating glacial and interglacial periods

Radiometric dating

Technique used to date materials such as rocks or carbon

Type of forest with high rainfall

Small valley, often due to stream erosion

Real-Time Automated Personnel Identification System

Recrystallization (geology)

Metamorphic process that occurs under temperature and pressure where atoms of a mineral are reorganized by diffusion and/or dislocation glide

A layer of loose, heterogeneous superficial deposits covering solid rock

Relative dating

Determining the relative order of past events

Remineralisation

Breakdown of organic matter to simple chemicals by living organisms

Ancient ocean which separated two major palaeocontinents, Gondwana and Laurussia

An igneous, volcanic rock, of felsic (silica-rich) composition

A geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance

A proposed driving force for tectonic plate motion as the result of the lithosphere sliding down the raised asthenosphere below mid-ocean ridges

A linear zone where the Earth's crust is being pulled apart, and is an example of extensional tectonics

Linear lowland created by a tectonic rift or fault

Interface between land and a river or stream

Wave structures created in sediments by bottom current

British fashion company

River morphology

Change in shape and direction of river channels over time

Topics referred to by the same term

Naturally occurring mineral aggregate

Hypothetical neoproterozoic supercontinent from between about a billion to about three quarters of a billion years ago

Roundness (geology)

The smoothness of clastic particles

Rubidium–strontium dating

Radiometric dating technique for rocks and minerals based on the quantities of specific isotopes of rubidium (87Rb) and strontium (87Sr, 86Sr)

Variety of corundum, mineral, gemstone

Transverse seismic wave

Coastal ecosystem between land and open saltwater that is regularly flooded

Granular material composed of finely divided rock and mineral particles

Type of sedimentary rock

U.S. amateur radio satellite

Mixed woodland-grassland ecosystem

Medium grade metamorphic rock with lamellar grain

Broken rock fragments at the base of steep rock faces, that has accumulated through periodic rockfall

A cave formed by the wave action of the sea and located along present or former coastlines

A mountain rising from the ocean seafloor that does not reach to the water's surface

Particulate solid matter that is deposited on the surface of land

Sediment gravity flow

Sediment transport mechanism

Sediment transport

The movement of solid particles, typically by gravity and fluid entrainment

Sedimentary basin

Regions of long-term subsidence creating space for infilling by sediments

Sedimentary basin analysis

Sedimentary rock

Rock formed by the deposition and subsequent cementation of material

Sedimentary structures

Geologic structures formed during sediment deposition

Seismic intensity scales

Seismic refraction

Deviation of seismic waves by rock or soil layers to characterize subsurface geologic structures

Seismic tomography

Technique for imaging the subsurface of the Earth with seismic waves produced by earthquakes or explosions

Seismic, volcanic, or explosive energy that travels through Earth's layers

Scientific study of earthquakes and propagation of elastic waves through a planet

Sequence (geology)

Geological events, processes, or rocks, arranged in chronological order

Sequence stratigraphy

Study and analysis of groups of sedimentary deposits

Series (stratigraphy)

Sequence of rock depositions defining a chronostratigraphic unit corresponding to a specific epoch on the geologic time scale

Fine-grained, clastic sedimentary rock

Shear (geology)

In geology, the response of a rock to deformation usually by compressive stress

Structural discontinuity surface in the Earth's crust and upper mantle

Shield (geology)

A large stable area of exposed Precambrian crystalline rock

Low profile volcano usually formed almost entirely of fluid lava flows

Beach which is armoured with pebbles or small- to medium-sized cobbles

Natural submerged sandbank that rises from a body of water to near the surface

A large region of volcanic rock in Russia

Carbonate mineral

Silicate mineral

Rock-forming minerals with predominantly silicate anions

Biogenic pelagic sediment located on the deep ocean floor

A tabular intrusion between older layers of rock

Nesosilicate mineral

Classification of soil or sediment

Sedimentary rock which has a grain size in the silt range

Third period of the Paleozoic Era 444-419 million years ago

Depression or hole in the ground caused by collapse of the surface into an existing void space

The portion of a tectonic plate that is being subducted

The part of the motion of a tectonic plate caused by its subduction

Metamorphic rock

An Archaean craton in the north-western Canadian Shield, in Northwest Territories and Nunavut

Worldwide glaciation episodes during the Proterozoic Eon

Soft-sediment deformation structures

Geologic formation

Soil (American band)

American rock band

Soil acidification

Buildup of hydrogen cations, which reduces the soil pH

Discipline embracing all chemical and mineralogical compounds and reactions occurring in soils and soil-forming processes

Soil classification

Systematic categorization of soils

The ability of a soil to sustain agricultural plant growth

Process of soil formation

A state of soil, meeting ecosystem functions

Soil layer whose physical characteristics differ from the layers above and beneath

Soil morphology

Branch of soil science dedicated to the technical description of soil and soil profiles containing multiple horizons

Measure of the acidity or alkalinity in soils

The study of soil's physical properties and processes

The study of soil as a natural resource on the surface of the earth

Property of a soil

Solutional cave

Cave formed in soluble rock such as limestone, chalk, dolomite, marble, salt beds or gypsum

South American plate

Major tectonic plate which includes most of South America and a large part of the south Atlantic

South magnetic pole

Wandering point on the Earth where the geomagnetic field lines are directed vertically upwards, at 64°S 137°E as of 2015 in the Southern Ocean

A structure formed in a cave by the deposition of minerals from water

Zinc-iron sulfide mineral

Spherical Earth

Approximation of the figure of the Earth as a sphere

A mineral or gemstone

Stage (stratigraphy)

Unit in stratigraphy

Elongated mineral formation which hangs down from a cave ceiling

Elongate mineral formation found on a cave floor

Nesosilicate mineral

Ecoregion of plain grasslands without trees

Stratigraphic section

Sequence of layers of rocks in the order they were deposited

Stratigraphic unit

Volume of rock defined by its petrographic, lithologic or paleontologic features

The study of rock layers and their formation

Type of conical volcano composed of layers of lava and tephra

Layer of sedimentary rock or soil with internally consistent characteristics

Channel bottom of a stream, river, or creek

Orientation or attitude of a geologic feature

Structural basin

Geological depression

Structural geology

Science of the description and interpretation of deformation in the Earth's crust

Sturtian glaciation

Glacial Snowball Earth event ~700 Ma ago

A geological process at convergent tectonic plate boundaries where one plate moves under the other

The motion of a surface (usually, the Earth's surface) as it shifts downward relative to a datum such as sea-level

Sulfate mineral

Class of minerals that include the sulfate ion

Sulfide mineral

Nickel–Strunz 9 ed mineral class number 2

Point on a surface with a higher elevation than all immediately adjacent points

Landmass comprising more than one continental core, or craton

Volcano that has erupted 1000 cubic km in a single eruption

Portion of sediment uplifted by a fluid's flow in the process of sediment transportation

A forested wetland

Rocksalt group, halide mineral

Type of geological fold

System (stratigraphy)

A sequence of rock layers that were laid down in the same geological period

Biome characterized by coniferous forests

Topics referred to by the same term

Tectonic uplift

The portion of the total geologic uplift of the mean earth surface that is not attributable to an isostatic response to unloading

Temperate broadleaf and mixed forests

Temperate rainforest

Forests in the temperate zone

Terra Australis Orogen

Terrace (geology)

A step-like landform

Mesozoic ocean between Gondwana and Laurasia

The Island, Croydon

High-rise residential building in London, England

Theory of tides

Scientific interpretation of tidal forces

Thermochronology

Branch of geology studying the age of isotopic systems

A type of reverse fault that has a dip of 45 degrees or less

Island accessible by foot at low tide

Unsorted glacial sediment

Health of soil, suitability for growing

Topics referred to by the same term

Element of low concentration

Transform fault

Plate boundary where the motion is predominantly horizontal

First period of the Mesozoic Era

Triassic–Jurassic extinction event

Mass extinction ending the Triassic period

Triple junction

The point where the boundaries of three tectonic plates meet

Tropical rainforest

Specific ecosystem

Rock consolidated from volcanic ash

Biome where plant growth is hindered by frigid temperatures

The geologic deposit of a turbidity current

Type locality (geology)

Geologic term regarding rock types, stratigraphic units or mineral species

Distorted sediment deposition

Uninhabited island

Island without permanent human population

Upland and lowland

Uranium–lead dating

Type of radiometric dating

U-shaped valley

Valleys formed by glacial scouring

Low area between hills, often with a river running through it

Van Allen radiation belt

Zone of energetic charged particles around the planet Earth

Sheetlike body within a rock

Elements and compounds that are readily vaporized

Chain of volcanoes formed above a subducting plate

Landform of ejecta from a volcanic vent piled up in a conical shape

Volcanic island

Island of volcanic origin

Rock formed from lava erupted from a volcano

Phenomena and processes associated with the action of volcanos, geysers and fumaroles

Volcano (1997 film)

1997 American film

The study of volcanoes, lava, magma and associated phenomena

Place where water flows over a vertical drop in the course of a river

Breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, water, and biota

Western Interior Seaway

Large prehistoric inland sea that split the continent of North America

Land area that is permanently or seasonally saturated with water

Single chain calcium inosilicate (CaSiO3)

Land covered in trees

Yellowstone hotspot

Volcanic hotspot in the United States

Zirconium silicate, a mineral belonging to the group of nesosilicates

Measure of relative carbon-13 concentration in a sample

Measure of the ratio of stable isotopes oxygen-18 and oxygen-16