Exam 8: Volcanoes and Plutons

Volcanic ____ consist(s) of the smallest particles formed when liquid magma explodes into the air.

If you have two rocks and one contains small amounts of water, it will generally melt at a lower temperature than an otherwise identical dry rock.

Explain what the differences are between aa and pahoehoe basaltic lava and identify what their magma chemistry is.

Which list correctly orders magma rock going from highest silica and water content to lowest?

If you see a large circular depression in the ground in a volcanic region, what specific type of feature is it?

The Columbia River plateau in the northwestern United States is an example of a(n) ____, in which lava covers the landscape like a flood.

A cinder cone volcanic eruption is typically active for only a short period of time because once the gas escapes, the driving force behind the eruption is removed unlike composite volcanoes which represent repetitive eruptions.

Nearly all of Earth's oceanic crust is created by ____________.

Generally, as the concentration of _______ decreases in magma rocks, its melting point temperature increases.

Regional predictions based on the concentration of volcanoes in an area can be used to determine the intensity of a particular eruption because each eruption will contain the same type and volume of magma.

Oceanic crust is typically composed of ____.

A sill igneous intrusion forms when magma is injected into a fracture that cuts across rock layers.

Lava and rock fragments commonly erupt from a(n) ____________________ located in the crater of a volcano.

The process of partial melting helped produce silica-rich continents because the source of the magma evolved from silica-poor mantle.

Explain how the partial melting of peridotite yields basalt magma.

If pure olivine melts at 1890°C and pure pyroxene melts at 1390°C, and peridotite is a mixture of the two, which of the following is a likely melting temperature for peridotite?

If large concentrations of sulfur dioxide molecules are released during volcanic eruptions like Pinatubu of 1991, this can reflect sunlight in the upper atmosphere and cause atmospheric cooling for Earth's climate.

Explain how a batholith can contain smaller plutons within its system and provide an example of this.

The Yellowstone Volcano results from a shallow ____________________ that lies far from the nearest plate boundary similar to Hawaii which is in the middle of the Pacific Plate.