Large igneous province
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A large igneous province (LIP) is an extensive region of basalts resulting from flood basalt volcanism. When created, these regions often occupy a few million km2 and have volumes on the order of 1 million km3. In most cases, the majority of a LIP's volume is emplaced in less than 1 million years. Some LIP's lie on continental crust, while others lie beneath the oceans ("oceanic plateaus").
Many scientists argue that LIPs form as the result of mantle plumes that have only just arrived at the surface of the Earth. When a plume first arrives, they argue, the excess heat and chemical differences lead to an extended period of volcanism. Only subsequently does the plume cool and produce the kind of narrow channel of volcanism associated with features like the Hawaiian Islands. However, other scientists argue that large igneous provinces result from rifting and in particular the pulling apart of newly formed continental rifts without the need for deep seated plumes. Potentially both theories may lead to LIP formation.
Because, in several cases, a LIP may have occurred simultaneously with oceanic anoxic events and extinction events, it has been proposed that the volcanic byproducts of LIP formation may have had a profound and deleterious effect on the global environment.
Several examples of LIPs
- Brazilian Highlands
- Caribbean-Colombian Plateau
- Central Atlantic Magmatic Province
- Deccan Traps
- Permian Emeishan Large Igneous Province
- Ethiopian Highlands
- Jameson Land
- Kerguelen Plateau
- Ontong Java Plateau
- Parana basalts
- Siberian Traps
- Columbia River Plateau
- Northern Cordilleran volcanic province
See also
External links
- http://www.largeigneousprovinces.org
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