Download 1 Rocks and weathering new

Rocks and
weathering
granite
LO: to define what a rock is
and explain the process of
weathering
Discuss with your partner,
1. What is a rock?
2. How are these rocks
different?
3. How can you change a rock?
marble
Gabbro
(large crystals, slow cooling in the
Earth)
This is
obsidian. It
is a glassy,
igneous
A rock is a rock.
mixture of different
minerals made up of interlocking
grains.
This is gabbro. Like granite, it
This is
for instance,
granite contains
granite. It is also a course-grained rock.
quartz, feldspar
and mica.
is a coursegrained
with
There are rock
three
types of rock:
large, shiny and
igneous, sedimentary
crystals.
metamorphic.
This is
pumice. This
rock
This is a conglomerate. It
absorbs
water very consists of rounded pebbles set
in a mixture of finer grains
easily.
This is
obsidian. It
is a glassy,
igneous
rock.
What words would you use to describe these rocks?
This is gabbro. Like granite, it
This is
granite. It is also a course-grained rock.
is a coursegrained
rock with
large, shiny
crystals.
This is
pumice. This
rock
This is a conglomerate. It
absorbs
water very consists of rounded pebbles set
in a mixture of finer grains
easily.
What has happened to these rocks?
1
2
3
Physical weathering
http://www.bbc.co.uk/schools/ks3bitesize/science/chemistry/rock_cycle_2.shtml
Weathering is
It is the breakdown of rocks by physical
and chemical processes.
Erosion is
Erosion is the wearing away of rocks by wind,
moving water and ice (glaciers). These usually
contain weathered rock debris. Rock fall under
gravity is also erosion.
Transportation is the movement of rocks to
different areas
Videos and demo
Freeze Thaw Weathering
Freeze thaw
(weathering)
demo
Level assessed task: explain how a
landslide occurs
White cliffs of dover
as an example
Weathering and erosion circus
Activity 1 looks at the effect of pouring water onto brown sugar to
simulate the effect of water on soluble rock.
Activity 2 looks at the residue left after water samples have
evaporated to show that water can dissolve minerals.
Activity 3 shows that water expands on freezing by placing a
sealed jar of water in the freezer overnight and looks at the effect
of freezing on a water-soaked sample of porous rock
Activity 4 simulates the effect of water impact on rocks by
pouring water on sand.
Activity 5 uses a hair dryer to simulate wind erosion by
‘sandblasting’ copper sulfate crystals from a cylinder of Blu-Tack®.
Plenary- story of a weathered rock
• Write a short story about a rock that explains
chemical and physical weathering including
the key words below:
• Acid rain
• Freeze, thaw, breakdown, rock, physical,
weathering, hot, cold, joints, crystals, porous.
• I am a rock in the hot desert sun……………..