Online quiz #6 Flashcards
(21 cards)
Which of the following igneous rocks crystallizes at Earth’s surface?
Basalt
How do you describe a rhyolite?
fine-grained igneous rock rich in sialic minerals
Andesite is an example of a(n) ____________ igenous rock:
intermediate
How do you describe an andesite?
a fine-grained, intermediate igneous rock
Which igenous rock has the same chemical composition as basalt?
Gabbro
Which pair of intrusive and extrusive rocks has the same chemical composition?
gabbro and basalt
Which type of igenous rock crystallizes deep within Earth’s crust?
gabbro
Which mineral crystallizes from a magma at the lowest temperature?
quartz
What type of rock makes up most of the Hawaiian Islands?
basalt
What type of magma forms at mid-ocean ridges?
Mafic
Which magma composition will be produced by melting of the upper mantle?
Mafic
The main difference between intrusive and extrusive igneous rock is:
where they solidify
Mantle plumes generate large volumes of ________ magmas
Basaltic
Magma is, by definition,
molten rock below the surface
Which igenous rock is the most abundant component of the crust and makes up nearly all the seafloor?
Basalt
At approximately what temperature does olivine crystallize from a melt?
1200°C
What type of magma forms when the upper mantle undergoes decompression melting?
Mafic
What is molten rock beneath Earth’s surface called?
Magma
High-temperature lavas are less viscous than low-temperature lavas.
True
What is the eruption temperature of basaltic lava?
1000°C to 1200°C
Which gas is a main constituent of volcanic gas?
water vapor
