Which of the following igneous rocks has a pyroclastic texture?
1.
Rhyolitic tuff
The sizes, shapes, and arrangements of mineral grains in an igneous rock is known as
1.
Texture
Changing the composition of magma by incorporating surrounding host rock is known as
1.
Assimilation Olivine and quartz commonly crystallize together from mafic or basaltic magmas
1.
False
Which igneous rock or magma has the lowest silica content?
1.
Basalt
Lava flows are typically finer grained than intrusive rocks. Why?
1.
The extrusive magma cools quickly so the mineral grains do not have time to grow
A feldspar crystal where a calcium rich interior is surrounded by a sodium rich rim indicates that there was incomplete reaction between the crystal and surrounding magma
1.
True
Andesitic magma can form through differentiation of granitic magma
1.
False
Consider Bowen's reaction series. Which mineral would you expect to see as a phenocryst in a porphyritic
basalt?
1.
Olivine
What texture describes an igneous rock that has two or more distinctly different-sized populations of mineral grains?
1.
Porphyritic
Which of the following igneous rocks has a phaneritic texture?
1.
Gabbro
The formation of a secondary magma of different composition from a parent magma is called magmatic differentiation
1.
True
What type of magma, commonly erupted along oceanic ridge systems, originates by partial melting of mantle peridotite?
1.
Basalt
Which of the following pairs of igneous rocks have the same composition?
1.
Basalt and diorite
What is the name of a volcanic rock that is extremely vesicular and glassy?
1.
Pumice
All of the following are factors that affect the generation of magma except for
1.
Crystal size
is thought to be common in the Earth's mantle but rare in the crust.
1.
Peridotite
Which of the following factors or processes influence the composition of magma?
1.
All of the above On the basis of Bowen's reaction series, which of the following minerals has the lowest melting temperature?
1.
Quartz
On the basis of the figure, which of the following statements is most accurate?
1.
Dry basalt melts at a higher temperature than dry granite
Decompression melting in the generation of magma is common along...
1.
Mid-ocean ridges
