Science 7: Earth᾿s Crust and Resources
Lesson 1: Rocks and The Rock Cycle
Rocks are classified into 3 major groups
Igneous Rock
- Igneous means “fire”
- Igneous rocks make up over 4/5’s of the Earth’s Crust
- forms when hot magma (or lava) cools and solidifies
- Magma is melted rock found below the Earth's crust and it is called lava after poured out onto the
Earth’s surface
- Types of Igneous rock are:


intrusive (cooled and hardened magma below the Earth's surface
extrusive (rock that forms when lava - magma released during a volcanic eruption - cools on the surface)
- Magma can contain crystals, their size depending on how quickly or slowly the rock cools (large crystals form when the rock cools slowly)
Sedimentary Rock
- is formed from sediment (loose material - rock, minerals, plant and animal remains - that is layered and compacted together by the pressure of the material above it)
- It is the most layered rock and makes up about 75% of the exposed rock on the surface
- stratification is the visible evidence of the layers
- cementation - some of the minerals that dissolve with the addition of water, makes a natural cement that glues the pieces of sediment together.
Types of sedimentary rock include:



 shale (formed from fine clay or mud) sandstone (sand, made of quartz) conglomerate (pebbles and small stones cemented together) limestone (organic sedimentary rock, containing fossils - plant and animal remains)
Metamorphic Rock
This type of rock has changed its form from what it was originally. It is formed below the Earth's surface by extreme pressure and heat
- the parent rock will become another type of rock depending on how much pressure and heat is used to change it
- example: shale ---» slate ---» schist
Taken and adapted from http://www.edquest.ca/component/content/article/158/
| Print |

The Rock Cycle is a group of changes. Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock.
Metamorphic rock can change into igneous or sedimentary rock.
Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. Igneous rock can form underground, where the magma cools slowly. Or, igneous rock can form above ground, where the magma cools quickly.
When it pours out on Earth's surface, magma is called lava. Yes, the same liquid rock matter that you see coming out of volcanoes.
On Earth's surface, wind and water can break rock into pieces. They can also carry rock pieces to another place. Usually, the rock pieces, called sediments, drop from the wind or water to make a layer.
The layer can be buried under other layers of sediments. After a long time the sediments can be cemented together to make sedimentary rock. In this way, igneous rock can become sedimentary rock.
All rock can be heated. But where does the heat come from? Inside Earth there is heat from pressure
(push your hands together very hard and feel the heat). There is heat from friction (rub your hands together and feel the heat). There is also heat from radioactive decay (the process that gives us nuclear power plants that make electricity).
So, what does the heat do to the rock? It bakes the rock.
Baked rock does not melt, but it does change. It forms crystals. If it has crystals already, it forms larger crystals. Because this rock changes, it is called metamorphic. Remember that a caterpillar changes to become a butterfly. That change is called metamorphosis. Metamorphosis can occur in rock when they are heated to 300 to 700 degrees Celsius.

When Earth's tectonic plates move around, they produce heat. When they collide, they build mountains and metamorphose (met-ah-MORE-foes) the rock.
The rock cycle continues. Mountains made of metamorphic rocks can be broken up and washed away by streams. New sediments from these mountains can make new sedimentary rock.
The rock cycle never stops. http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html
What are some common uses for rocks? Can rocks be used for healing? Recuperative powers?
Ceremonies?
Lesson 2: Minerals
Rocks are built by minerals, which are pure naturally occurring substances. There are more than 3000 different minerals, some very common like the ones found in your body like iron, and some are very rare. Granite is a rock that is often used now for many uses including as in kitchens. If you look very closely at it you can often see some sparkling grains which are a mineral called feldspar, glassy crystals, which are a type of quartz, and white or black flakes which are mica.
Some minerals, such as copper and gold, consist of a single element, which is a pure substance that can not be further broken down. Other minerals are made up of a number of elements put together in a specific chemical composition. For instance, quartz is made up of silicon and oxygen.
To identify minerals, we look at specific properties:
1.
Lustre – does it reflect light
2.
Streak – does it leave a mark when rubbed on a surface
3.
Hardness – Use of Moh’s Hardness scale which rates 10 different minerals to see which mineral will scratch the surface of another to find its place in the table
4.
Colour – can be used, but some minerals have multiple colours
5.
Texture – Smooth or rough, does it have flat sides
6.
Number of Faces – number of sides
7.
Break – how does the mineral break? There are two main ways, it can fracture and break into rough, uneven surfaces or it can split along a plane that is parallel to it face known as cleavage.
Labs on Minerals, and Rocks using Line Masters 4-11 to 4-13.
Lesson 3: Erosion
Please complete the rock experiments.
Rocks and minerals can be broken down in two main ways. The first, Erosion, is the movement of rock and mineral grains from one place to another. The second type is Weathering (3 types), which breaks down and wears away rock, creating sediment.

Mechanical Weathering
- the physical break-up or disintegration of rocks, caused by gravity, temperature change and frost
wedging. Mechanical can occur naturally or it can be done by man.
Chemical Weathering
- chemicals, present in the Earth”s surface or atmosphere, can be dissolved in water and react in the chemical decomposition of rocks and minerals (acid rain)
Biological Weathering
- living organisms (plants, animals, bacteria and fungi ) can breakdown rock
- plant roots, acidic fluids produced by roots, bacteria, fungi and some insects and small animals can cause chemical reactions
The Changing Surface of the Earth
- agents of erosion include: glaciers, gravity, wind, and water
- changes can occur gradually (glaciers) or suddenly ( flash floods, landslides, rock slides)
- large rocks caught up in a glacier and then left behind when the glacier recedes are called erratics
- sediment that is push away, as the glacier moves forward, are called oraines
- scratches, made in the bedrock, by glaciers carrying rocks are called striations
- gravity causes landslides and rock slides
- wind carries rock particles across the landscape, eroding the land by abrasion (planting vegetation, contour farming and reduced tillage can reduce the effects of wind erosion)
Water in Motion
- Water is one of the most powerful causes of erosion
- Sudden or incremental changes occur due to the movement of water - rivers, rain, ocean waves
- When a river becomes mature it begins to meander (curving its bed from side to side)
Taken from: http://www.edquest.ca/component/content/article/159/
These processes which break rocks and minerals down lead to the formation of soils.
Lesson 4: Soil
So how does soil form anyway?
Please watch the following animation and answer these questions:
What are the four main components of soil?
What is the percentage of each component?
Write a quick description of how the process of soil formation occurs.
Soils, like ground water are a renewable resource although the time taken for renewal runs into the hundreds or thousands of years. The material underlying the soil must have time to decompose chemically and to break down into fine particles. This is the geological process of weathering.

Then, there must be time for plants and other organisms to do their work of converting mere weathered rock into a true soil. Because of the length of time involved, it is important that our present soil resource be protected from erosion, loss of fertility through harmful agricultural practices, and pollution. It was calculated in 1976 by a soil scientist at the
University of Saskatchewan, that Saskatchewan soils had lost about 50% of their organic matter during the 75 years or so of cultivation. About 40% of Canadian arable land lies in
Saskatchewan.
Why does this province have an especially high responsibility to protect its soil?
We will try this lab:
1.
Find a source for soil which is typical to your region. (The school playground might not necessarily be typical, as much of the organic matter has likely disappeared or compacted over the years. An undisturbed field, or farmers field may be a better example.)
2.
Place about two handfuls (or two cups) of dirt from the sample into a 1 litre sealable glass container. (A sealer would work good, the kind your grandmother makes pickles in would be ideal.)
3.
Fill the container about 3/4 of the way to the top with water.
4.
Stir and shake the container very very thoroughly, making certain that the contents are well mixed. Be careful not to drop the glass container!
5.
Allow the container to settle for 24 hours.
6.
Without disturbing your container, examine it carefully.
1.
What happened?
2.
What do you notice?
3.
How many distinct layers can you identify?
4.
Measure and describe each of the layers: How thick are they precisely?
What colors are they?
5.
Create a pie graph that indicates the color and thickness of each layer.
Please obtain the map of Saskatchewan so that we can colour in the specific soil regions of
Saskatchewan on the map. Please look at the original map to get the proper soil zones coloured into your map. On the back of the map we will define each of the soil zones by using the following link: http://esask.uregina.ca/entry/soils.html
To look at the specific soils of Saskatchewan, we need to go the following link: http://www.soilsofsask.ca/index.php?option=com_content&task=view&id=17&Itemid=69
We can use the following link to review the soil formation process:

http://www.harcourtschool.com/activity/dirt/index.html
Research Project on mining:
To begin this project, we will try to list some of the many minerals mined in Saskatchewan.
To complete this project we will the following link for a map: http://www.saskmining.ca/index.php/map/Map/map.html
Please fill in Line master 4-14 and 4-15 to collect your data. Next, you will describe the difference between open – pit mining, underground mining and solution mining in how they are each done, and how each of them effects the environment. To conclude your project, you need to explain how the location of a mine is determined. In other words, how do they know the mineral they are looking for is in the ground at that place? (some hints include core sampling drilling, magnetometer and satellite imaging). Please display your information in paragraphs so that each major point has its own paragraph.
Lesson5: Plates and Pangaea
To begin this section, each student will need to bring in their atlas, pencil, glue and a pair of scissors.
First, place trace the continents of the Earth onto a piece of paper as they appear in your atlas. Second, cut out the continents that you have just traced as close as you can to their outer lines. Third, try to dry fit the continents together like a jigsaw puzzle. Once you have the continents stuck together, get it checked and then glue down your continents on a new piece of paper. Please hand this paper in. http://vimeo.com/14258924
There is a belief that the continents were at one time a single supercontinent called Pangaea. In 1915, a
German Scientist named Wegener proposed the idea of Pangaea based on the suggestion that the continents fit together as you have just shown and that the similarities in fossils and rocks on the current continents. His theory was not really accepted until the 1960’s when scientists found both the
Mid Atlantic Ridge, a mountain range in the middle of the Atlantic Ocean much larger and newer than any mountains on the surface, and the Ocean Trecnches found on the edges of the oceans. These trenches can be as deep as 11000 m, compared to the Grand Canyon which is only 1700m deep!
With all of this evidence, scientists proposed the idea of plate tectonics which proposes that the Earth’s surface is broken into many large sections called plates. These plates move on the surface of the Earth allowing for the formation of different land masses. The Mid Atlantic Ridge formed where two plates are moving apart allowing molten rock to flow through into the ocean forming new rock. The ocean trenches occur where one plate flows under another forming a deep trench.
Project: Can we create a Model of the Earth?
So, you know what the Earth looks like and you know that there are many tectonic plates that are currently moving around the surface, but what does the inside look like? Are there more than one layer? Can you create a model?

Requirements of the model:
_____ (3) Surface (shows the continents and oceans)
_____ (4) Shows each layer (crust, mantle, outer core, inner core) with clear labels
_____ (3) Can explain how model was made and define each layer of the Earth
Your model can be made out of anything that you would like to use, including any type of food that you would like to use. Please be sure to have some fun and create a model that you will fun making! Please use the following link to find an example of a created model: http://www.ehow.com/how_4495708_make-model-earth_s-layers.html
Lesson 6: Mountains
We will begin by watching the following video and copying some definitions in our books: http://youtu.be/nfziy_860GU
Cookie Subduction
The following is taken and adapted from: http://www.edquest.ca/component/content/article/163/
It takes many years to create mountains and we do not expect to see them created in our life time.
Mountain Formation and Distribution
- most mountains are large areas that have uplifted due to the movement (converging, diverging or sliding) or heating of tectonic plates, where the build up of heat and pressure can cause folding and faulting
- sedimentary rock under slow, gradual pressure can fold (bend like plastic because they are made soft by the heat) or break - and can be changed to metamorphic rock in the process
- the upward, or top part of folded rock is called anticline, the bottom is called syncline
- rock that is too brittle to fold under heat and pressure, will break, called thrust faulting
- when older rock ends up on top of younger rock as a result of thrust faulting, the result is the formation of fault block mountains
- movement of rock along a fault can be vertical or horizontal and can be traced by the location of the 'basement rock' on both sides of the fault
- mountains can be formed by the convergence of continental and oceania plates (the Continental plate is lighter and rides over the Oceanic plate) a combination of processes creates complex
mountains
Ages of Mountains
- mountains that are jagged at the top are 'young' mountains, while those that are more rounded
(due to erosion and weathering) are 'old' mountains
Applications
- subduction of the Juan de Fuca plate (off the west coast of North America) has caused folding, faulting and uplifting, as well as magma has created volcanoes.
- the Himalayas are the youngest mountain range with the highest mountains (and still growing)

- one of the oldest ranges is the Laurentian Mountains, in Quebec (they are being worn down)
How the Rocky Mountains Formed: http://www.geo.arizona.edu/geo5xx/geo527/Rockies/flatsub.html
Lesson 7: Volcanoes http://youtu.be/s2i4XS0Esks
Taken and adapted from: http://www.edquest.ca/component/content/article/162/
A volcano is an opening in the Earth's crust that releases lava, steam and ash when it erupts (becomes active). The openings are called vents . When volcanoes are not active, they are called dormant .
Famous Volcaoes
- the eruption of Mt. Etna in Italy this past summer shows that volcanoes cannot be predicted and don't always behave in ways scientists think they will behave.
- the most active volcano on the Earth is Kilauea in Hawaii ( Loihi is a new volcano forming beside the main island in Hawaii - creating a new island) http://youtu.be/488BkTUsMa4
- Krakatau , in Indonesia (blast was heard 4800km away and tsunamis waves were 30 m high)
- Mount St. Helens , in Washinton (sideways and vertical eruptions)
- Mount Vesuvius , in southern Italy (City of Pompeii was buried - it is due for another large eruption because it is sealed with a 'rock plug' that could blast 1.5 km upwards)
- Mount Pinatubo , in the Phillipines (ash circled the globe and cooled temperatures around the world)
Applications
- Volcanoes on Lo , one of Jupiter's moons have been photographed using Vidicon - a type of TV camera mounted on the Voyager spacecraft, using an electron gun and photoconductor
- those on Mars and our moon have been extinct for millions of years, while those on Venus may still be erupting
- the largest volcano found in our universe is the extinct Olympus Mons on Mars
For further information on volcanoes, we will read and make a few notes from the following link: http://www.planetseed.com/node/93114
Lesson 8: Earthquakes http://youtu.be/VSgB1IWr6O4
Info taken and adapted from: http://www.edquest.ca/component/content/article/161/
Earthquakes occur when tectonic plates move suddenly
Measuring Earthquakes
- scientists called seismologists use a seismograph to record the intensity of an earthquake
- the seismograph must be attached to bedrock (the solid rock that lies beneath the soil and looser rocks) to feel the vibrations on the plate
- a marking pen, inside the seismograph, records the vibrations on a rotating drum (modern

seismographs are electronic)
- the measurement scale used is called the Richter scale http://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Kinemetrics_seismograph.jpg/200px-
Kinemetrics_seismograph.jpg
Earthquake Waves
- seismic waves are the energy waves that travel outward from the source of the earthquake.
- aftershocks are actually smaller earthquakes
Types of Earthquake Waves
- Primary or p waves are the fastest and can push through solids, liquids and gases
- Secondary or s waves travel more slowly and can only pass through solids
- Surface waves are the slowest of all, but their rolling motion can be very destructive (like a ripple effect on water)
- primary waves are bent or refracted as they travel (the area where they do not come through the other side of the earth is called a shadow zone
Locating an Earthquake
- it is possible to determine the location of an earthquake by the interval between the p waves and the s waves (the farther apart they are, the further away the earthquake is
- the source of an earthquake deep in the crust is called the focus, where the p waves and s waves originate
- the surface waves come from the epicentre (the location on the surface directly above the focus)
Earthquake Zones
- the zones of greatest intensity (8 or more on the Richter scale) 1 off Canada's west coast, 8 in Mexico, and 8 in Alaska
Types of Rock Movement in Earthquakes
- where the plates meet, the rock is under great pressure, which can make it bend and stretch - when the pressure is too great, the rock breaks suddenly creating a fault
- there are three types of movement, of the tectonic plates, along a fault
- Normal Faults, (pulling action, which breaks rocks apart) - North Atlantic
- Reverse Faults (compression, where rocks are squeezed, causing them to bend and break) - Marianas
Trench, near Japan
- Strike-Slip or Transform Faults (shear causes slipping, which makes the jagged edges break off) - Pacific
Plate
Preparing for Earthquakes
- stabilize furniture, storage of heavier items close to the floor, earthquake-resistant designs (allow building to bend a little)

Other Effects of Earthquakes
- tsunamis (Japanese word meaning 'harbour wave') are huge waves that happen when an earthquake occurs under the ocean http://youtu.be/dJBS94GVyuo http://youtu.be/oWzdgBNfhQU
- avalanches or rock slides occur in mountains as a result of an earthquake
- type of foundation upon which building are constructed can have an effect on the severity of the earthquake (liquification)
Applications
- Ancient predicting device used a pot with eight dragon heads on it, with little balls inside the heads and frogs to catch the balls (the frog that caught the ball indicated the direction of the earthquake) p. 395
- Animals: rabbits hop wildly for several minutes, deep-sea fish swim close to the surface, catfish jump out of the water, bees evacuate their hives, and mice are dazed before an earthquake
Do earthquakes occur in Canada? http://earthquakescanada.nrcan.gc.ca/index-eng.php
Complete the map of Mountain Ranges, Volcanoes and Earthquakes around the World with the use
Activity 4-9 and 4-11.
For review, please watch: http://www.bozemanscience.com/science-videos/2011/6/26/plate-tectonics.html