lesson 5 – igneous rock earth unit. objectives students will identify the characteristics of...
TRANSCRIPT
Lesson 5 – Igneous Rock
Earth Unit
Objectives
•Students will identify the characteristics of igneous rock.•Students will understand how rocks are formed.
Vocabulary
• Igneous rock: rocks formed when magma from inside the earth cools and hardens on the earth’s surface.• lava: magma that has
reached the surface of the earth• magma: hot, liquid rock
formed deep inside the earth
a rock is made of two or more minerals.
ROCKS ARE DIVIDED INTO THREE GROUPS BASED ON HOW THE ROCKS FORMED
hOW ARE rOCKS fORMED?
• Today we will be using the rock formation chart to help us understand the formation and location of igneous rocks.
• Materials:• red and orange
crayon• pencil• formation chart
Igneous rocks or fire rocks are formed from hot, molten materials called magma. They can be found where volcanoes have or do exist.
Magma is is
found beneath
the earth’s
surface.
Igneous rocks are created when molten rock (lava) inside the Earth pushes through the crust (like in a volcanic eruption) and then cools
Intrusive (plutonic) Igneous Rocks
• Intrusive rocks are made when magma that is blocked from reaching the earth’s surface cools slowly below the earth’s surface. Intrusive igneous rocks cool slowly deep within the earth and produces large crystals.
click here for more examples
Color the magma
orange, stop before
reaching the earth’s
surface.
QUARTZ GRANITE
intrusive igneous Rocks
The slow-cooling process creates large crystals and appear coarse-grained. Some examples of these are:
GABBRO
Extrusive (volcanic) igneous rocks
• Lava is the name for liquid magma that reaches the earth’s surface by flowing out of volcanoes. • The lava cools rapidly
forming extrusive rocks which have small, fine grained crystals or glassy appearance.
Color the lave red
click here for more examples
If the cooling is instantaneous a glassy texture
may form
If gas bubbles are trapped as the
lava rapidly cools a vesicular
texture may occur
EXTRUSIVE igneous Rocks
OBSIDIAN PUMICE
is a fine-grained, dark-colored
extrusive igneous rock
BASALT
https://www.youtube.com/watch?v=PrN7jygu4cQ
Review
•With a partner and your chart explain:•How igneous rocks are formed•What magma is and where it can be found•What lava is and where it can be found• Intrusive and extrusive rocks