Lesson 4.2

Question 1

are formed from
solidification of magma or lava
which flows out from depth.

Answer 1

Igneous rocks

Question 2

are the components of almost
all types of igneous rocks.

Answer 2

Minerals such as quartz, feldspar,
pyroxene, olivine, amphibole, and
mica

Question 3

Igneous rocks are
characterized by

Answer 3

intergrowth of crystals and/or
volcanic glass.

Question 4

Crystal size is _
proportional to the cooling
rate of magma.

Answer 4

directly

Question 5

are formed
deep underground,

Answer 5

Big crystals

Question 6

are formed
near the surface.

Answer 6

smaller crystals

Question 7

forms
when magma or volcanic fragments
erupt and solidify on Earth’s surface
which results in very fine-grained
rock with very small crystals that
could not be seen through naked
eye.

also known as a volcanic rock

Answer 7

extrusive igneous rock

Question 8

forms when magma
crystallizes within the crust
and is composed of
medium to coarse grains. It
is also known as a plutonic
rock.

Answer 8

intrusive igneous rock

Question 9

Igneous rocks can be named using the binary system which
is mainly based on its

Answer 9

texture
composition

Question 10

It is directly proportional to the cooling rate of magma. This means that when the crystals are big, it denotes that the rock is formed deep underground
since the magma has a longer trip to the surface giving it longer time to cool down
at a very slow rate. On the other hand, magma cools quickly (fast cooling) near the
surface that causes formation of smaller crystals since it is given few time to form.

Question 11

Crystals form when magma are cooled. A general model is created to show the
progression of silicate crystallization at specific temperature. It is called

Answer 11

Bowen’s
reaction series

which is developed by petrologist Norman L. Bowen

Question 12

2 branchs of bowen’s reaction series

Answer 12

discontinuous branch
continuous branch

Question 13

discontinuous branch

Answer 13

olivine
pyroxene
amphibole
biotite mica

old people are boring

Question 14

continuous branch

Answer 14

calcium rich plagioclase feldspar

to sodium rich plagioclase feldspar

Question 15

3 textures of extrusive igneous rock

Answer 15

smooth
full of holes
wit hlarge crystals embedded in a fine ground mass

Question 16

examples of extrusive igneous

Answer 16

obsidian
pumice
andesite

Question 17

two types of intrusive bodies

Answer 17

concordant and discordant

Question 18

When the pre-existing rock bed is cut across by an intrusive body

Answer 18

concordant

Question 19

while if it runs parallel to the bedrock, igneous rock bodies are called

Answer 19

discordant

Question 20

sills

Answer 20

concordant

Question 21

dikes and laccolith

Answer 21

discordant

Question 22

are large intrusive bodies formed deep within Earth

Answer 22

Batholiths

Question 23

textures of igneous rocks

Answer 23

aphaneitic
phaneritic
pegmatitic
vesicular
porphyritic
amygdaloidal
pyroclastic

Question 24

has crystals that are too fine-grained to be seen by the naked
eye or even with the help of a hand lens

Answer 24

Aphanitic

Question 25

has grains that are coarse enough to be visible to the eye

Answer 25

Phaneritic

Question 26

has crystals are greater than 3 cm due to very slow cooling

Answer 26

Pegmatitic

Question 27

contains tiny holes called vesicles due to gas bubbles in the
lava or magma

Answer 27

Vesicular

Question 28

are rocks where larger crystals are embedded in smaller crystals

Answer 28

Porphyritic

Question 29

is when vesicles are filled by low-temperature minerals after
the solidification of magma

Answer 29

Amygdaloidal

Question 30

is formed from the consolidation of individual rock fragments
that are ejected during a volcanic eruption.

Answer 30

Pyroclastic

Question 31

igneous rock is usually light colored and contains large amounts of
quartz, potassium feldspar, and plagioclase.

is also called granitic igneous
rock

Answer 31

Felsic

Question 32

igneous rock is medium gray or medium green and consists
of major minerals like amphibole, plagioclase, and feldspar

Answer 32

Intermediate

Question 33

igneous rock is dark gray to black-colored and composed largely of
plagioclase and amphibole with small amounts of olivine.

is also called as
basaltic igneous rock.

Answer 33

Mafic

Question 34

igneous rock has a very dark green to black shade and consists
largely of olivine and pyroxene.

Answer 34

Ultramafic

Question 35

Types of Igneous Rocks Based on Mineral Composition

Answer 35

Felsic
Intermediate
Mafic
Ultramafic