Earth Sciences 2240F/G Lecture Notes - Lecture 9: Siberian Traps, Subduction, Deccan Traps
17 Dec 2017
School
Department
Course
Professor
Document Summary
The final category of volcanic eruptions is flood basalts. This is a controversial topic since its only happened once in human experience however scientists believe it is the cause of 2 mass species extinctions. Continental flood basalts (cfbs) are erupted at rifts from the tops of mantle plumes, and primarily large ones termed super plumes. Super plumes are such strong pulses of heat from the core-mantle boundary that the generate enormous volumes of partial melt. Partly because the upper lithosphere acts as a insulator but largely because of reduction in pressure, the top of the super plume mushrooms out, thus basalt may pour out onto the surface from a number of fissures. They may occur on the oceanic crust, continental crust, or a mix of both. By definition, large igneous provinces are large volcanic basalt rock that are created by the process other than normal sea floor.
