Exam 4: Igneous Rocks and Intrusive Igneous Activity

What is a pluton?

Trapped gases in cooling lava form cavities called ____________________. Cinder cones may contain large amounts of ____________________, which contains more of these cavities than it does rock.

Rapid cooling of magma results in a(n) ____________________-grained texture called ____________________.

Igneous rocks formed by explosive volcanic activity have a texture that is termed:

Andesite and ____________________ are respectively ____________________ and ____________________ rocks formed in volcanic chains along ____________________ plate boundaries.

What is an igneous rock?

Igneous rocks with a two-stage intrusive-extrusive origin are recognized by a texture that is:

Most plutons form:

According to Bowen's reaction series, crystal settling should result in magma being separated in lower layers rich in the early-formed ____________________ minerals, and upper layers enriched in later-formed ____________________ minerals.

The process of assimilation results in the cooling of an intruding magma.

The most widely accepted explanation for chains of volcanoes in the oceans and lines of volcanoes on land is that they formed at:

The processes of crystal settling and assimilation have been shown to produce large quantities of felsic magma from mafic magmas.

Intrusive igneous (plutonic) rocks:

What role does stoping play in the emplacement of batholiths?

The two main categories of igneous rocks are ____________________/____________________ and ____________________/____________________.

Batholiths and stocks can be important sources of minerals, such as ____________________ and ____________________.

When magma cools slowly, crystal growth proceeds at a relatively ____________________ speed, and the resultant rock is ____________________ in texture.

List three processes by which felsic and intermediate igneous rocks can be formed from more mafic magmas.

How does a batholith differ from a stock?

The largest intrusive bodies are called ____________________, and, by definition, they must have at least ____________________ square kilometers of surface area.