Name________________________
Chapter 6
Date______________
Information for reference and reading is found on pp120-125, section 6.2, of chapter 6
Question
Main Idea & Supporting Details
 Igneous comes from the Latin word “_______” meaning ________
#1 How do igneous rocks form?
 created from _____, ________, magma rising from the upper mantle & _____________
 magma cools and _____________
 bodies formed _______________ are known as ____________
#2 How are igneous rocks
classified?
Two Characteristics:
*composition → ___________________
*texture→ ___________, _________, ______________, and ________________ of minerals
#3 What determines the texture of
igneous rocks? What are they?
Texture is determined by_______________and ____________ of cooling:
#1 glassy: ____________, no grain or crystal structure, cooled ________ ____________
#2 fine-grained: ____________________ mineral crystals, _______________
#3 coarse-grained: ____________________ mineral crystals, crystals ____________ to the eye
#4 porphyritic: ____________ ____________ scattered in a ___________________ background
Igneous Rock Composition: Starting material of the magma can be classified as Felsic and Mafic which determines the final composition.
FELSIC
MAFIC
thick, _________________, cooler
hotter, _______________, more fluid
__________ of silica
______________ of silica, more ________________
fewer _________ minerals such as ________________
more __________colored minerals like __________ &
_______________
magma tends to __________ up on existing _________
_____________
typical rock is ____________
___________ silicate minerals- hornblende,
_____________, & biotite
can _______________between __________ layers
more easily
typical rock is _______________
Igneous Rock Texture: The texture of these rocks is determined by the rate at which they cool so location is everything!
INTRUSIVE
Hardens very slowly _______________________
_______________ bodies = thousands of years to __________
Intrusive rocks appear above ground after _______________
& _______________
Have a ______________ grained texture due to __________
cooling- visible crystals
Includes: ____________, ____________, ____________
EXTRUSIVE
Magma that has _______________ onto the earth’s surface
creating ____________
Cooling is ____________ at the surface
___________________ or no crystal formation because of
rapid _______________
Texture varies from _________________ to _____________
Includes: ____________, _____________, rhyolite,
______________, basalt
“All in the Family: Gabbro vs. Granite vs. Diorite”: Igneous rocks are grouped into families according to mineral composition
GRANITE FAMILY
Form from:
________________ _____________
Typical minerals include:
Quartz
_______________
Mica
________________
Intrusive member: GRANITE
Contains large amounts of _______________
Family Members:
Granite
Texture: __________ ______________
Color varies:
___________to__________to_________
Obsidian
Appears at the surface after _______________
Most common igneous _________________ rock
Felsite
Extrusive member: OBSIDIAN
Volcanic rock with _____________ texture
________________ fracture
Chemical composition similar to ______________
Contains ___________ colored ________________
Form from:
_________________ Magma= mixture of _________
& ___________ minerals
Typical minerals include:
Pyroxene
_________________
Feldspar
_________________
Biotite
__________________
Mica
___________________
DIORITE FAMILY
Family Members:
D____________
A____________
Intrusive member: DIORITE
Texture: ______________________
Less ______________ than granite & less
______________ feldspar then gabbro
Extrusive member: ANDESITE
Texture: _____________________
Similar composition to _______________
Form from:
_____________ ____________
GABBRO FAMILY
Family Members:
Intrusive member: GABBRO
Texture: ____________________
___________ colored
_______________
Typical minerals include:
______________
Olivine
________________________
______________
Biotite
Diabase
Basalt
______________
Extrusive member: BASALT
_________ ______________ member
Texture: ____________________
Dark __________ or __________
Most common rock on the ____________
__________; makes up most land ________ ________