Igneous Identification Flashcards
(32 cards)
sources of heat in the earth
primordial heat and radioactive decay
how are melting temp and pressure related
proportionally, as pressure increases/decreases so does temp
how does addition of water vapor affect melting temp
lowers melting temp
what type of melting occurs at mid ocean ridges and hot spots
decompression melting
which minerals have the lowest melting point (first to melt, last to crystallize)
felsic; high silica
which minerals have the highest melting point (last to melt, first to crystallize)
mafic: high Fe and Mg
in fractional crystallization, the liquid portion has more of which type of mineral
felsic/silica-rich minerals
high viscosity means
more resistant to flow, and slower moving
dike
intrusive rock cross cutting other rock layers
sill
intrusive rock parallel to rock layers
stock
main “plumbing tube” of the volcano
which mineral has lower viscosity
mafic
which mineral has higher viscosity
felsic
which mineral will form shield volcanoes
mafic
caldera
explosive eruption when a magma chamber collapses on itself
pyroclastic flow
fast moving flow of lava, hot ash, and gas
aphanitic texture
fast cooling, fine grained
porphorytic texture
large grains surrounded by smaller grains
phaneritic texture
slow cooling, coarse grained
intrusive rock texture
mostly phaneritic
extrusive rock texture
mostly aphanitic
amorphous solid
rapid cooling, no visible crystals
vesicles in intrusive rock usually indicate . . .
the rock crystallized close to the surface
mafic rocks appear _____ in color
darker
