Bowen's reaction - Answers a simple schematic description of the order in which different minerals
crystallize during the cooling and progressive crystallization of magma
intrusive - Answers an igneous rock that forced its way in a molten state into the country rock
extrusive - Answers an igneous rock formed from lava or from other products of volcanic material
spewed out onto the surface of the earth
country rock - Answers the rock into which an igneous rock intrudes or a mineral deposit is emplaced
magma/melt - Answers molten (liquid) rock
lava - Answers magma that has reached the surface
partial melting - Answers a process in which heating melts some of he minerals in a mass of rock while
the rest remains solid. This process occurs because the minerals that compose a rock melt at different
temperatures
deompression melting - Answers the kind of melting that occurs when hot mantle rock rises to shallower
depths in the Earth so that pressure decreases while the temperature remains unchanged
assimilation - Answers the process of magma contamination in which blocks of wall rock fall in to a
magma chamber and dissolve
volatiles - Answers elements or compounds such as water or carbon dioxide that evaporate easily and
can exist in gaseous forms at the Earth's surface
geothermal gradient - Answers the rate of change in temperature with depth
felsic - Answers describes a light colored igneous rock that is poor in iron and magnesium and contains
abundant feldspars and quartz
intermediate composition - Answers a compositional group of igneous rocks that contains at least 25%
dark silicate minerals. The other dominant mineral is plagioclase feldspar
mafic - Answers describes dark-colored minerals rich in iron and magnesium, and relatively poor in silica
(ex:P pyroxene, amphibole, or olivine)
ultramafic - Answers an igneous rock consisting mainly ofmafic minerals and containing less than 10%
feldspar (ex: peridotite, amphibolite, and dunite)
granite - Answers a felsic, coarse grained, intrusive igneous rock composed of quartz, orthoclase
feldspar, and micas. Rhyolite is its extrusive equivalent
andesite - Answers a volcanic rock type intermediate in composition between rhyolite and basalt; the
extrusive equivalent of diorite.