Geol Ch. 4

Front 1

Geologists do all of the following to study the processes forming igneous rocks except:

Back 1

sampling of the asthenosphere

Front 2

Which of the following can be used to estimate the composition of an igneous rock:

Back 2

mineral content

Front 3

An igneous rock with no quartz and no olivine would be considered:

Back 3

Intermediate

Front 4

Although geologists can only see extruded volcanic materials, several lines of evidence allow them to infer simultaneous magma intrusion beneath an active volcano. Landslides due to magma movement at depth are recorded prior to and during volcanic eruptions. Volcanoes often eject pieces of plutonic rock during an eruption. Erosion of volcanic rocks reveal plutonic rocks at depth.

Back 4

The word "Landslides" should be replaced by " Earthquakes ".

Front 5

Exposed bodies of intrusive rock larger than 100 square kilometers in area are called:

Back 5

batholiths

Front 6

The distinction between batholiths and stocks is arbitrary BECAUSE it is due in part to the degree of erosion of the pluton, stocks may be small parts of batholiths that have not yet been exposed.

Back 6

The assertion and the reason are both correct, and the reason is valid.

Front 7

A volcano composed of interlayered lava flows, lava-flow rubble, and pyroclastic deposits is called a:

Back 7

composite volcano

Front 8

What is the expected order of crystallization in a cooling basaltic magma?

Back 8

Olivine, followed by plagioclase feldspar and finally by pyroxene

Front 9

Igneous rocks are overwhelmingly composed of silicate minerals BECAUSE the silica content of magma ranges from 45 to almost 80 percent by weight.

Back 9

The assertion and the reason are both correct, and the reason is valid.