Name
Date
\-.rc.J5
Rocks . GuidedReadingand Study
lgraeous
Rocks
Thissectiondesufbesthecharactristicsand usesof igneousroclcs.
Classifyimg
lgme@$s
Rocks
ce
1. Cirde the letter of the definition of igneousrock.
a. Rockthat forms from minera]s
m
CN
I
b. Rock that containsiron
c. Rock that forms from magmaor lava
d. Rock that containscrystals
oo
ca
a
P.
P.
$.Is the following sentencetrue or false?Extrusiverock forms beneath
Earth'ssurface.
{,,Cirde the letter of eachsentencethat is true aboutbasalt.
a. It forms oceaniccrust.
b.It is the most cdmmonintrusive rock.
i"n
\-{
+h
c. It forms from lava.
d.It forms beneathEarth'ssurface.
C)
$,Circte the letter of eachsentencethat is true aboutgrairite.
a. It is the most abr.:ndantintrusive rock in continentalaust.
b. It forms the coreof many mountajn ranges.
c. It forms from magma.
d. It fonns on top of the crust.
q-+
v
r p.{
-ll
;J
rF1
\J
>)
'rc
Ft
&The textureof an igneousrock dependson the sizeand shapeof its
, 7. Is the following sentmcetrue or false?Igneousrocks with similar
mineral compositionsaiwayshave the sametextr:res.
+-)
V)
(n
V
F-l
P\
Matdr the type of texfureof igneousrockswith how rocks of that texture
rval.l[,
TypeofTexture
8. fine-grained
9. coarse-glained
trO.porphyryrock
IIowRocks ofThatTexfureFonn
a. Magma coolsin two stages.
b'Lava coolsrapidly'
c' Magmacoolsslowly'
tu/
ra
F{
n
,i\
fi
b0
ts-{
11. Is the following sentencetrue or false?Intrusive rocks have smaller
aystals than extrusive rocks.
12. A rock with large crystalssu:rounded by small crystalsis called
13. \Alhattype of texture do extrusiverockssuch asbasalthave?
14. What is obsidian?
15. Describethe texture of obsidian.
16. Cirde the letter of eachsentencethat is true aboutthe silica composition
of igneousrocks.
a. Igneousrocks low in silica areusually dark-colored.
b. An exampleof an igneousrock low in silica is granite.
c. Igneousrockshigh in silica are usually light-coiored.
d. An exampleof an igneousrock high in silicais basalt.
L7. Describethe different minerals that determjnethe color of granite.
L8. How do geologists determine the mineral composition of granite?
L9. \Mry havepeoplethror-rghouthistory usedigneousrocks for tools and
building nraterials?
20. Describethreeways granite hasbeenised tfuoughout history.
a.
b.

BIBLIOGRAPHY

Chapter 5 Test, Form 28