Chapter 4

Created by deborahtovar 

Upgrade to
remove ads

19 terms · Igneous Rocks

Igneous rocks form by the?

solidification of magma or lava

Importance of igneous rocks?

building materials, ores

Igneous rocks distribution?

Canadian Shield, Rocky Mtns, Appalachian Mtns, Central TX

Igneous rocks compose __% of basement rock. 85% is metamorphic.

15

What are the two types of magma/lava?

silicic and mafic

What is silicic magma/lava?

>50% SiO2, gooey, highly viscous, becomes explosive, convergent system associated with continental crust formation.

What is mafic lava/magma?

<50% SiO2, very fluid, non-explosive, quiet, low viscosity, divergent associated with oceanic crust.

Silicic rocks are generated with __ zones at __ plate boundaries as magma chambers.

subduction, convergent

Silicic rocks process via __.

magnetic differentiation

When solidified, magma chamber becomes a __ composed of granite and/or diorite.

batholith

Stratovolcanoes form by alternating __ of pyroclastic material (ash) and thick __ flows.

eruptions, lava

Caldera formation from collapsed craters are like?

cracks

What is divergent?

plates moving away from eachother

what is convergent?

plates moving toward one another

Mafic rocks are generated at __ (divergent plate boundaries).

ridges

Mafic rocks are also generated within the __ crust.

oceanic

Shield volcanoes due to extensive outpouring of __/basaltic lava with little pyroclastic material.

mafic

What is intrusive?

magma

What is extrusive?

lava

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

NEW! Voice Recording

Click the mic to start.

Create Set