Geology HW 07

Yellowstone is best described as which of the following?

An active volcano that has erupted in the last 1 million years

Batholiths are known to form the cores of mountain ranges such as the Sierra Nevada. What is the implication of this observation?

Because batholiths form deep within Earth, the occurrence of one at the surface implies that it has since been uplifted and/or the rocks above have been removed.

Which of the following was a stage in the formation of Yellowstone caldera?

Crust bows upward above a magma chamber.

In general, why does Earth's crust sit on top of the mantle?

Earth's crust is less dense than the mantle.

How are felsic magmas formed?

Heat from the mantle melts part of the lower crust.

How do mafic volcanic rocks get to Earth's surface?

Pressure from overlying crust forces mantle magmas through cracks to Earth's surface. These magmas erupt out of volcanoes, cool, and solidify into rock.

Which of the following pieces of evidence for a past volcanic eruption are present at Yellowstone National Park?

Pyroclastic material Lava flows A caldera rim

Which of the following features at Yellowstone National Park is evidence for a magma chamber beneath the park?

Rising (or bowing upward) ground near Yellowstone River Welded tuff Geysers and hot springs (steam)

In general, when will melted rock in the mantle rise?

almost always

Which of the following terms is best described as a massive pluton?

batholith

What drives melting at divergent boundaries?

decompression melting

What is the term for a tabular igneous pluton that occurs in an orientation that is discordant with the bedding surfaces of adjacent sedimentary rocks?

dike

What type of boundary is present along the eastern boundary of the North American plate?

divergent oceanic-oceanic

While working in the field, you find a dike cutting across some sedimentary rocks. What grain size would you expect to find in this pluton?

fine-grained

At what tectonic setting is Hawaii located?

oceanic hot spot

What is the term for a tabular igneous pluton that occurs in an orientation that is concordant with the bedding surfaces of adjacent sedimentary rocks?

sill

Which of the following tectonic settings does NOT produce volcanism?

transform boundary

What type of volcanism characterizes the ring of fire?

volcanism caused by convergent oceanic-continental boundaries volcanism caused by convergent oceanic-oceanic boundaries

When will magma rise to Earth's surface?

when the magma is less dense than adjacent rock