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Glossary continued

 

Anoxia: A term which means that there is a loss of oxygen from the environment in this case the oceans.

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Basaltic A term for a rock of basalt composition.  Basalt is a dark coloured fine grained  igneous rock, consisting of iron and magnesium minerals. A rock type commonly erupted from volcanoes in places like Hawaii.

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CO2 : The chemical formula for carbon dioxide, one of the greenhouse gases

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Crater: a saucer shaped depression on the Earth’s surface resulting from a meteorite impact or bomb explosion.

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Earth scientists: a broad term for all Earth-related sciences, including geology, geoscience, meteorology etc.

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Flood Basalt Provinces: Areas that are covered in basaltic magma, that resulted from the rise of magma through the surface of the earth.

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Greenhouse gas: Is a gas that traps  heat into the atmosphere.  The gas works in the same way as the glass in a greenhouse.  Heat energy enters the atmosphere, in a short wave-length form, however when the energy reflects off the earth it is in long wave form and so is trapped in the earths atmosphere.

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Igneous: A term used to describe the type of rocks that are generated by melting, i.e. from a volcano.

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Impact melt: (also impactite glass) the substance formed when extreme heat is generated as the result of the impact shock of a large meteorite.

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Impactor: The term used for a Meteorite which enters a planets (earths) atmosphere and collides with the surface of the planet.

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Iridium anomalies: these have been found at various K-T boundaries around the world after Walter Alvarez in 1979 discovered them in Italy. They are known only to be associated with meteoritic impacts. The deposits are generally 1-2cm thick and form when fine ash settles from the atmosphere months after the impact has thrown meteorite particles rich in iridium.

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K-T event: this is the abbreviation given to the Cretaceous/Tertiary boundary. At this point in history, it is widely accepted that a Meteorite struck the earth, and as a result of this impact, many species on both land and sea became extinct. Most famously, the dinosaurs became extinct. (For More Info, Click Here See Impacts Effects Page)

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LIPs': Large igneous province.  The term given to extreme 'volcanic' eruptions which generate large amounts of lava and gases.

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Ma: this is used as an abbreviation for one million years (106 years), and can be used to state how many years ago something occurred e.g. dinosaurs became extinct 65 Ma, means that dinosaurs became extinct 65 million years ago.

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Magmatic: From the geological term Magma, meaning molten rock. i.e. magmatic province means, an area formed from originally molten rocks.

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Meteorites: any extraterrestrial solid mass that reaches the earth’s surface, usually referring to exceptionally large fragments belonging to one of three classes.

1)      Siderites – composed entirely of iron and nickel which are the most frequently found

2)      Siderolites – stony iron meteorites composed of both iron and nickel as well as silicate

      3)   Aerolites – composed mainly of silicate minerals, these are the most frequently observed to fall.

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Methane hydrates: Are essentially areas of methane ice, they are deposited in tundra or ocean floor conditions.  Since they are frozen they have a much smaller volume than when in their gas form.  This means they expand explosively. NOTE: Methane has the chemical formula CH4 i.e. carbon and hydrogen

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Orbital forcing: A term used to describe, when the climate of earth is controlled by astronomic events, such as the orbit of the earth around the sun, which is something which is known to bring about significant changes in climate.

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Phanerozoic: meaning ‘visible life.’ An Eon,  named due to the sediments which accumulated at this time containing obvious plant and animal remains. It includes all stratigraphic systems from the Cambrian period to the present.

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Photosynthesis:  The breakdown of carbon dioxide and water, in the presence of sunlight to produce sugars and oxygen.

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ppm: The abbreviation for parts per million

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Residence time:   Is the time a certain chemical stays in this case the atmosphere, it is a balance of the amount in, the amount out and the size of the reservoir

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Rifting: The splitting of a continent, a feature seen in the East African Rift Valley today.  Rifting often results in the generation of large volumes due to the effect of decompression of underlying rocks which are close to their melting temperatures.

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Shock waves:  compressional waves that are formed whenever the speed of an object, relative to the medium in which it is traveling, exceeds the speed of sound transmission for that medium.

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Shocked quartz: during a meteoric impact or nuclear explosion shock metamorphism can alter minerals (especially quartz) due to the high temps and pressures which are produced over a very short period of time, in conjunction with the shock waves present.

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SO2: The chemical formula for Sulphur Dioxide.  

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Stratosphere: is a region of the atmosphere from about 4.5 miles to 10 miles up, in this region temperature does not decrease with height.

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Tektites: A small rounded mass consisting almost entirely of glass. It is thought that tektites result from large meteoritic impact on earth; under the force of impact, solid rock in instantaneously changed into drops of molten liquid, which then solidify as a glass.

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Tsunamis: Giant waves which are formed by any large-scale, short-duration disturbance of the free sea surface. Caused generally by an earthquake of magnitude greater than 6.5 on the Richter scale. When the wave approaches a coast, the shallow water causes it to become taller and taller, until it crashes over the coastline. These sorts of waves can be very destructive and dangerous as they move so rapidly that there is little time for evacuation of populated areas even when there is acknowledgement of a wave approaching.

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Tsunami deposits: These deposits are formed when a tsunami wave looses enough energy to deposit the load it is carrying. These deposits generally contain sediment from a number of different sediment environments, both from shallow marine and from continental regions.

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