Volcanoes and plate boundaries Flashcards
Mantle plume
A stationary area of high heat flow
How do island chains form?
Plate moves over the mantle plume where there is Volcanic activity at a fixed point
What are the key features of an oceanic- oceanic divergent boundary? 3
Mid ocean ridge, axial rift, pillow lavas
What are the key features of a convergent oceanic- oceanic boundary? 5
subduction zone, volcanic island arc, benioff zone, intermediate volcanoes, deep sea trench
What are the key features of a convergent oceanic- continental boundary? 6
subduction zone, Benioff zone, deep sea trench, rising magma, batholiths, rhyolitic volcanoes
What are the key features of a convergent continental- continental boundary? 3
fold mountains, batholiths, ophiolites
Name the most common rock type formed by the eruption of the Hawaiian volcanoes
Basalt
How do batholiths form in volcanoes?
continental crust is melted by magma, most of the material will remain separate because of the different viscosities. Melted silicic material forms large granite batholiths deep within fold mountains later exposed by erosion.
What are deep ocean trenches?
long, narrow parts of the earth’s surface, formed as the ocean floor is dragged down where two plates converge.
What are fold mountains/ how do they form?
form on the edges of the continents parallel to the subduction zone. compressional features made of folded and faulted sediments that have been scraped off the descending plate onto the non-subducting plate. High pressure result in regional metamorphism.
What is a benioff zone?
A zone of earthquake foci sloping down at an angle of about 45 degrees from the deep ocean trench.
guyot
flat topped seamount usually eroded away by wave action
seamount
a submarine mountain often an extinct volcano
diapir
low density, buoyant materials rising upwards
super volcano
a very large volcano
