ISL #10
Rocks Reading Guide and Presentation Notes
Integrated Science 4
5/14
Per.
Name
 Rocks Reading Guide
Directions: Read pp. 743-760 in your Integrated Science textbook and answer the questions below.
1. What are all rocks made of?
2. Complete the chart below about the three types of rock.
Rock Type
How does it form?
Key characteristics
Examples
Igneous
Metamorphic
Sedimentary
3. Consider Figure 2 on page 744. Discuss how igneous, metamorphic and sedimentary rock are linked
together through the rock cycle.
4. Our focus this unit will be on igneous rock. What is the difference between magma and lava?
5. Compare and contrast intrusive and extrusive igneous rock. Consider depth of formation, crystal size
and gas content.
6. How are igneous rocks classified according to composition?
 Rocks Presentation Notes
I.
Composition of the Earth’s Crust
A. The earth’s crust is composed of ____________.

A rock is defined as two or more _______________, found in the earth’s crust bonded
together in a ______________ form
B. ________ of the earth’s crust is composed of the following 8 elements:
 Silicon, Oxygen, Aluminum, Magnesium, Calcium, Sodium, Potassium, and Iron
II.
Rock Types
A. _________________________ rocks
 formed by the hardening and cementing of ________________ of sediment
B. _________________________ rocks

formed when rocks that already exist are changed by ____________ and pressure into new
kinds of rock
C. __________________________ rocks

III.
IV.
formed by _____________________ and hardening of hot molten rock from ____________
the Earth
The Rock Cycle
Studying Igneous Rocks
A. Color:

Indicates differences in
_______________________
_______________________
B. Crystal size (mm):

Indicates the __________ of cooling of a
rock

Rocks with larger crystals cooled
more ____________ than rocks
with smaller crystals
C. Density: mass/volume

Indicates differences in _________
of formation and chemical
composition
 More dense rocks form from magma that originates _______________ in the mantle.
V.
Igneous Rock Formation
A. Three major factors affect the chemical composition, crystal size and density of igneous rock:
1. ______________ of parent magma.
2. ____________________ between the parent magma and the rocks of the crust
3. ___________ of cooling
VI.
Types of Igneous Rocks
A. Intrusive Igneous Rock

Definition: rock formed ______________________ when magma cools
 Magma: molten (liquid) rock found ____________ the earth’s surface
B. Extrusive Igneous Rock

VII.
Definition: rock formed ____________________________ when magma cools
 Lava: molten (liquid) rock that ________________ from the crust through cracks or fissures
Igneous Rocks Characteristics
A. Felsic rock

Chemical Composition: High percent of silicates (Si) and water. Low percent of iron (Fe),
calcium (Ca), & magnesium (Mg)

Color: ___________________________

Viscosity (The degree to which a substance resists flow): High

Trapped gases: _______________

Relative Density: ___________

Volcanic source: Explosive volcanoes and cinder cone
 Location: __________________
B. Mafic Rock

Chemical Composition: Low percent of silicates (Si). High in Calcium (Ca), Iron (Fe) and
Magnesium (Mg).

Color: ___________________________

Viscosity: Low

Trapped gases: _______________

Relative Density: ___________

Volcanic source: “Gentle” eruptions from broad shield volcanoes (ex. Hawaii)
 Location: _________________________
C. Andesitic (Intermediate) Rocks
VIII.

Chemical Composition: Intermediate percent of silicates (Si). Intermediate in Ca, Fe, Mg.

Color: ___________________________

Viscosity: Intermediate

Trapped gases: Intermediate amounts present

Relative Density: _________________

Volcanic source: Intermediate eruption volcanoes
 Location: _________________________
Plate Tectonics and Igneous Rocks