Magmatism(incom) Flashcards
defined as molten
rock material produced by
partial melting of the mantle and
crust. It contains liquids, gases,
crystals and rock fragments.
Magma
Temperature increases
with depth, which is called
_. This
increase will obviously
induce melting.
geothermal gradient
Decrease in pressure causes
adiabatic decompression. As
pressure is decreased, melting
temperatures of materials
decrease.
are substances that evaporate easily and can exist in gaseous form in the surface of Earth
Volatiles
Example of volatiles
water and carbon dioxide
is the process of reducing a substance’s melting point by introducing impurities. When volatiles are added to rocks, their melting point decreases.
Flux melting
When water or carbon dioxide are introduced to rock, flux melting occurs which cause the rock to melt.
occurs along plate boundaries or margins and sometimes within the plate.
Magmatism
In effect, hot mantle rock penetrates the crust and becomes magma.
Plate boundaries can be classified as convergent, divergent, and transform.
temperature, pressure, volatiles
Classification of Magma
Tholeiitic magmas or tholeiites
Calc-alkaline basalts
Alkaline basalts
Carbonatites
are produced by large degree of melting
Tholeiitic magmas or tholeiites
form along convergent plate boundaries above subduction zones
Calc-alkaline basalts
form from smaller degree of partial melting, which results in alkali-rich and silica depleted magma of diverse compositions
Alkaline basalts