a) mantle recompression
b) subtraction of heat
c) addition of heat
d) removal of volatiles
I think d) through knowledge of temp and pressure changes, but I feel I should know this as a fact. Thanks in advance.
b) subtraction of heat
c) addition of heat
d) removal of volatiles
I think d) through knowledge of temp and pressure changes, but I feel I should know this as a fact. Thanks in advance.
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A, and C.
Not B because heat is required for magma to form; subtraction of heat is not grammatically correct but if it means extraction of heat, then that can not form magma.
About D:
If you're thinking about the relieving of pressure from very hot rock by removing volatiles, causing parts of it to liquify - this is theoretically possible. However, a rock layer would have to be hot enough to form magma yet so pressurized it can't melt. To be at such an balance point that the influence of removal of volatiles, who under this pressure are either of almost no volume or will be spread out between the rock layer, can cause the transition to magma, seems to me to be very very rare. Id have to check some literature for it but I don't think its a realistic process, just a theory.
Not B because heat is required for magma to form; subtraction of heat is not grammatically correct but if it means extraction of heat, then that can not form magma.
About D:
If you're thinking about the relieving of pressure from very hot rock by removing volatiles, causing parts of it to liquify - this is theoretically possible. However, a rock layer would have to be hot enough to form magma yet so pressurized it can't melt. To be at such an balance point that the influence of removal of volatiles, who under this pressure are either of almost no volume or will be spread out between the rock layer, can cause the transition to magma, seems to me to be very very rare. Id have to check some literature for it but I don't think its a realistic process, just a theory.