Rocks and Fossils Flashcards
What are all rocks made up of?
Minerals
What are the three different families of rocks?
Sedimentary
Igneous
Metamorphic
Where do geodes form?
Inside magma
What do we call two types of molten rock?
Lava (above surface)
Magma (below surface)
What does water leave behind when it evaporates?
Minerals
Why do some geodes have different colour crystals?
Different types of minerals changes the colour
What causes there to be a “gap” in the molten rock?
When gas gets trapped in the rock it leaves pockets.
How many rocks can you name?
Granite
Obsidian
Limestone
Slate
Sandstone
Quartz
Marble
Flint
Chalk
Mudstone
Gneiss
Shale
What are rocks made up of?
A mixture of minerals and non-living creatures
Igneous rocks are formed in two ways, resulting in two types of igneous rock. What are they?
Intrusive (inside)
Extrusive (outside)
Draw and label a diagram showing an intrusive igneous rock formation.
Describe how intrusive igneous rocks form.
Inside the Earth’s Crust.
Large crystals form
Minerals have time to bond
Formed in magma.
Cools slowly
eg Granite.
An example of an intrusive igneous rock is…..
…. granite
Describe how extrusive igneous rocks form.
Outside the Earth’s Crust
Small crystals form
Minerals do not have time to bond
Formed in lava
Cools quickly.
eg. basalt
An example of an extrusive igneous rock is…..
…basalt
Draw and label a diagram showing an extrusive igneous rock formation.
Describe the formation of igneous rocks.
Key marks in a mark scheme
What does weathering mean?
Weathering erodes rocks at the surface to create smaller rocks (sediments).
What does transportation mean?
Creates sediments and rocks that are being moved by moving ice or wind.
What does deposition mean?
When rocks have stopped moving into the sea, river or desert and get deposited.
What does strata mean?
The layers that form in a sedimentary rock
What does lithification mean?
The process of turning into a sedimentary rock.
Create a diagram showing the formation of sedimentary rocks.
What happens during cementation?
The moisture squeezes out and the sediments stick together to create a sedimentary rock.
What is compaction?
It is when the bottom layers are squeezed together from the weight of the layers above and become compacted.
What is erosion?
The process of rocks being broken down.
Key information about intrusive rocks
Inside the Earth’s crust
Magma
Large crystals
Minerals have time to bond
Cooled slowly
eg. Granite
Key information about extrusive rocks
Outside the Earth’s Crust
Lava
Small crystals
Minerals don’t have time to bond
Cooled quickly
eg. Basalt
What does the word morph mean?
It’s when something changes form.
How are metamorphic rocks formed?
They are formed deep within the Earth where there is lots of heat from the magma below and lots of pressure from the rocks above.
What does the “parent rock” sandstone become when heat and pressure is applied to become a metamorphic rock?
Quartzite
What does the “parent rock” granite become when heat and pressure is applied to become a metamorphic rock?
Gneiss
What does the “parent rock” limestone become when heat and pressure is applied to become a metamorphic rock?
Marble
What does the “parent rock” shale or clay become when heat and pressure is applied to become a metamorphic rock?
Slate (low grade)
More pressure and heat
Phyllite
More pressure and heat
Schist
More pressure and heat
Gneiss (high grade)
What are metamorphic rocks?
They are rocks that have changed due to heat and pressure.
Examples of sedimentary rocks and uses
Limestone - making cement
Coal - fires
Chalk - writing
Sandstone - building material
Examples and uses of igneous rocks
Pumice - bath scrub
Granite - kerb stones
Examples of metamorphic rocks
Slate - roofing
Marble - making statues
Which rock is made up of layers that have been squashed together?
Sedimentary
Which rock is formed when lava or magma cools down and crystallises?
Igneous
Which rock is formed under intense heatand pressure causing it to change?
Metamorphic
How are igneous rocks formed?
Inside or outside the Earth’s Crust. They are formed by the cooling down of magma and lava.
What has happened to metamorphic rocks to make them the way they are?
Heat and pressure
Name a use for sedimentary rock
Creates fire or writing
Name as use for metamorphic rocks
Roofs and statues
Name a use for igneous rocks
Bath scrub
Give an example of a sedimentary rock
Coal, sandstone, puddingstone
Give an example of a metamorphic rock
Slate
Give an example of an igneous intrusive rock
Granite
Give an example of an igneous extrusive rock
Basalt, pumice, lava bomb, obsidian
What are sedimentary rocks formed from?
Sediments that have been compacted together.
What do we call the process of turning into a sedimentary rock?
Lithification
What name do we give the layers that form in a sedimentary rock?
Strata
Name two processes that cause rocks to be broken down into smaller pieces.
Weathering and sedimentation
What processes change a sedimentary rock to a metamorphic?
Heat and pressure
What processes change a metamorphic rock to an igneous?
Melting and cooling
What processes change an igneous rock to a sedimentary?
Sedimentation, compaction, weathering, erosion (lithification)
Why do we almost only find fossils in a sedimentary rock?
We can’t find fossils in igneous rocks as they would have melted. We find a few in metamorphic because they’ve experienced heat and pressure.
What is a fossil?
Remains of prehistoric plants and animals.
How do we know about animals that have died millions of years ago?
Fossils
What can we learn from a trace fossil?
How the animal lived and cared for its young.
How is a mold fossil created?
Mud around a dead animal hardens and creates a mold of the shape/imprint.
How is a resin fossil created?
When an insect gets stuck in the sap in the tree. The sap hardens and turns into amber which preserves the body.
Why is a body fossil rare?
A dinosaur needs to die near water and its skeleton cannot be scattered around.
How is a body fossil formed?
An animal dies.
Some body parts decay - usually only the skeleton is left.
The skeleton is covered in sand, earth, rock, seabed before the bones can disappear.
Minerals slowly fill the space in layers - in the exact shape of the bones.
Under lots of pressure, new minerals harden into rock.
Over a very long time, the bones break down and leave space, like an empty mould.
The earth is eroded away by the weather/sea. The fossil rock is exposed and discovered.
Which type of igneous rock forms from cooling magma?
Intrusive
Which type of igneous rock forms from cooling lava?
Extrusive
Which type of igneous rock has small crystals?
Extrusive
Which type of igneous rock has more time for minerals to bond?
Intrusive
Draw and label the rock cycle
What is the name of the process given to the constant creation and recycling of rocks on the Earth?
The Rock Cycle
