Essay On Mass Extinction

The world today has recorded a total of 5 main mass extinction events which are commonly known as the Big 5. A scientific journal (Benton & Harper, 2009) has stated that to classify an event as a mass extinction, it must meet the following criteria:

a) Extinction percentage of animals and plants must be atleast 30%

b) The event should happen in a short period of time

c) The level of extinction should be higher than the background extinction level

d) The extinction should happen across different regions

e) The extinction consists of different species of living organisms

Mass extinction is caused by major catastrophic events which are linked together directly and has the ability to wipe out living organisms off the face of the earth. This essay will cover on The

It is famous as this is the extinction which ended the rule of the dinosaurs. Scientists have suggested many different theories for the cause of this mass extinction but there is 2 hypotheses which are greatly favoured and accepted in the scientific world. The two hypotheses are: A large asteroid impact which caused a huge crater known as the chicxulub crater at the Yucatan Peninsula or a giant volcanic eruption of basaltic lava from the Deccan Traps in West-Central India.

In the K-T boundary, huge amounts of iridium has been found in rocks. Iridium is a very rare element on earth, much rarer than gold. At the K-T boundary, it has been found that the amount of clay iridium is at least twice the amount of gold and this high amount is usually only found in meteorites (Cowen, 2000). Not only is this element found in the rocks of the K-T boundary, it has also been found in the sediments of the ocean. It has been found that the iridium occurred in a layer just above the cretaceous fossils and the layer of sediments above the iridium belonged to the Cenozoic era (Cowen, 2000). In a study, Luis