Intraplate volcanism Flashcards
Give three examples of settings of intraplate volcanism.
Mantle hotspots, mantle plumes, and large igneous provinces (LIP).
Give an examples of where intraplate volcanoes are found.
Hawai’ian Islands
What type of melting occurs at intraplate settings?
Active upwelling
Define active upwelling.
Deep melting because of increase mantle potential temperature.
What does the increased mantle potential temperature tell us?
That there is a hot, convecting mantle plume.
What type of magma is produced at intraplate settings?
Ocean island basalt.
How is ocean island basalt produced?
Melting of dry mantle peridotite
Describe the positions of the geotherm and solidus at intraplate settings.
The geothermal crosses the solidus at deep depths due to the addition of heat.
Why do ocean island volcanoes have life cycles?
The lithosphere moves over the mantle plume.
What are the four life stages of an ocean island volcano?
Pre-shield, shield, post-shield, post-erosional
What type of magma is produced during the pre-shield, post-shield, and post-erosional life stages?
Alkali basalts
What type of magma is produced during the shield life stage?
Tholeiitic basalt
What type of trace elements is OIB depleted in?
Compatible elements (especially heavy rare earth elements)
