Exam 4: Up From the Inferno: Magma and Igneous Rocks

Which type of plate boundary hosts the most explosive volcanoes?

Magma tends to ________.

An oceanic plate subducting under another oceanic plate will create a(n)________.

Why is the outer core the only layer in Earth that is molten?

Volatiles refer to substances that ________.

Which type of magma has the greatest silica content?

If a body of magma is subjected to fractional crystallization,the first rock that is expected to crystallize from the magma will be ________.

The interior of Earth consists almost entirely of ________ rock.

List the four major magma compositions in order of silica content. Silica Content Highest Lowest Magma Composition

All other factors being equal,if a body of magma becomes more felsic,its viscosity will ________.

Volcanoes whose magma source is NOT linked to a plate boundary are associated with ________.

Volcanic eruptions at divergent boundaries generally take the form of ________.

An igneous rock with a mixed texture of coarse crystals (phenocrysts)surrounded by fine crystals (groundmass)is termed ________.

The two images below are of a rhyolite and a granite.First,label each rock with its proper rock name.Second,describe the difference in cooling history of the two rocks.

Despite the fact that the temperatures within Earth are hot enough to melt rock,Earth is mostly solid.Why do the rocks within Earth NOT melt?

Which of the following silicate minerals is often found in granite?

Given the solidus and liquidus curves below,which location represents material that is partially melted?

The image below is of a ________.

________ melting occurs at subduction zones because the down-going plate ________.

Which of the following is NOT a characteristic of the extrusive igneous rock obsidian?