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

Magma tends to __________ .

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?

Columnar jointing forms primarily because of __________

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

Rhyolite and granite are both felsic igneous rocks, although they have different cooling histories and, consequently, different textures. Explain the difference between the two rock types from a cooling perspective and be specific about which igneous texture can be applied to which rock.

Which of the following is most typical of what you would find in a lahar?

Ash, and larger fragments of pumice are all examples of __________ .

Volcanoes are able to cool global climate in which of the following ways?

Compare and contrast a dike and a sill. How are they similar? How are they different?

Decompression melting occurs at both __________ and __________ .

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

Important volatiles in magmas include __________ .

An important first step in mitigating volcanic hazards at a volcano is to __________ .

A sill is a(n) __________ .

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

All things equal, a magma will have __________ viscosity than a lava.

Which type of volcano forms from layers of mafic lava erupted in primarily effusive eruptions?

Describe the process of decompression melting; be sure to include an example of where this type of melting occurs within Earth.

In Bowen's discontinuous reaction series, the first mineral to crystallize out of a mafic melt is __________ .

The mantle is composed entirely of __________ .