Evidence For The Meteor Impact Which Killed The Dinosaurs

Glossary

Anomaly

Something that is unusual or unexpected.

antithesis

A theory or idea that opposes the idea being discussed.

Basaltic

A type of igneous rock ( made of crystals, solidified from magma ) that has a low level of silica, and rich in the minerals plagioclase and pyroxene.

Calcium Carbonate

A mineral made of calcium carbon and oxygen, abundant in the oceans and in warm shallow water form limestone rocks.

Carbon Dioxide

A gas that contributes to the greenhouse effect by trapping short ( infra red )wave radiation.

Carbonaceous Chondrites

There are several types of meteorite, this is one type; they are stony with sphere of silica in and a certain amount of carbon.

Cosmogenic

Originates from the space ( the cosmos ).

Cretaceous

The age the dinosaurs died out at the end of . The Cretaceous lasted from 125 to 65 million years ago. After the Cretaceous was the Tertiary period ( 65 to 2.5 million years ago ).

Element

An element one of the basic chemical ' building blocks' for example oxygen or hydrogen. Each element has characteristics which identify it as such. For more information on elements and their properties visit the Sheffield University Chemistry department page.

Extraterrestrial

Originates somewhere other than on the Earth.

hypothesis

An idea.

Impact Winter

After a large meteor hits the planet a form of winter occurs as the dust thrown up by the collision blocks out the sunlight and the warming rays that come with it, leaving the Earth very cold.

Iridium

Iridium is an element that occurs in the Earths crust in only tiny proportions, but is much more common in chondrite meteorites.

Isotope

Each element, e.g. oxygen, carbon or gold has a variety of types in the same way there are different types of car but they are all still cars, with elements it is the difference in their weight due to the number of neutrons present.

Isotopically Uniform

All of the samples of the element have the same weight and so they are the same isotope.

K-T Extinction / K-T Event

At the end of the Cretaceous ( K, from the German Kreide ) many species died ( about half ) this marks the change between this and the Tertiary ( T ) periods of the history of the Earth.

Laminar

Consists of flat sheet-like features.

Lithophile

A property that indicates it is preferentially partitioned into the crust of the Earth rather than anywhere else.

mantle

The hot main part of the Earth which underlies the crust.

Metamorphism

A change - usually applied to a physical change in something.

Meteorites

Lumps of rock which break through the atmosphere and come from space.

Photosynthesis

The process that plants use to donvert carbon dioxide to water and energy.

Platinum etc

Platinum ( and others mentioned with it ) are a group of rare elements that can tell us about the history of the material they were in.

ppb

'Parts per billion; how many parts in a sample that consisted of 1,000,000,000 parts would be what is being looked at. E.g. 500ppb carbon means that for a mass of 1,000,000,000 grams, 500 grams would be carbon.

Ruthenium etc

Ruthenium ( and others mentioned with it ) are a group of rare elements that can tell us about the history of the material they were in.

Smoking Gun

As an assassin is caught when they kill someone if they are found with a 'smoking gun' in hand, the impact crater would imply the K-T extinction was due to a large impact.

Spherules

Objects that are sphere ( ball ) shaped.

Strata

Layers of rocks.

Stratigraphic

Refers to stratigraphy, the record of the rocks and sediments in the area.

Stratosphere

The part of the gases around the world that are at a height of 10-50 km above the ground.

Subduction Zone

An area where oceanic crust slides beneath another piece of crust and is consumed by the heat inside the Earth.

tektites

Glassy silica rich meteorite that look very black and shiny.

Tsunamis / Tsunamites

Tsunamis are tidal waves, a tsunamite is the rock that is deposited by the tidal wave.

velocity

Another term for speed but also indicates a certain direction is involved.