Earth Sciences 2240F/G Chapter Notes - Chapter 9: Columbia Plateau, Columbia River Gorge, Continental Crust
26 Feb 2018
School
Department
Course
Professor
Document Summary
Massive eruptions called ood basalts" or continental ood basalts" or sometimes plateau basalts". Chapter 9 flood basalts and large igneous provinces appear in areas called large igneous provinces". Has happened only once in human experience. These events have been credited as being the primary cause of two species mass extinctions. The rst occurred 251 million years ago when 95% of all species on earth died. The second occurred 65. 5 million years ago when 70% of species died. Continental ood basalts are erupted on land at rifts from the tops of mantle plumes (primarily large. The difference between "normal" and "super" is the size of the end product. Superplumes are such strong pulses of heat from the core-mantle boundary that they generate enormous volumes of partial melt. Happens because the upper lithosphere acts as an insulator. Mainly because of a reduction in pressure from mantle to crust.
