Rock Types & Rock Cycle
What type of rock forms when molten rock cools and solidifies?
Igneous rock.
What type of energy does an object have when lifted above the ground?
Gravitational potential energy
What do we call the large pieces of the Earth’s crust that move slowly?
Tectonic plates.
Who proposed the theory of continental drift?
Alfred Wegener.
What is the outermost layer of the Earth called?
The crust.
Which rock type forms when sediments are compacted and cemented together?
Sedimentary rock.
When an object falls, this potential energy converts into what form of energy?
Kinetic energy.
Which type of boundary forms where plates move apart?
Divergent boundary.
How did the shape of continents support Wegener’s theory?
Coastlines like South America and Africa fit together like puzzle pieces.
Is the outer core solid or liquid?
Liquid.
Why does granite (intrusive) have large crystals while basalt (extrusive) has very small crystals?
Granite cools slowly underground → large crystals; Basalt cools quickly at the surface → small crystals.
What happens to Potential Energy and Kinetic Energy as a roller coaster travels downhill?
PE decreases; KE increases.
What feature forms when an oceanic plate subducts under a continental plate?
A volcanic mountain chain and a deep ocean trench.
Name one piece of physical evidence Wegener used to support his theory that the continents were once joined.
Similar fossils found in continents not connected
What is the mantle mostly made of?
Semi solid magma and silicate rock
What metamorphic rock forms from limestone?
Marble.
Name three types of energy involved when a candle burns.
Chemical → light + thermal (heat).
Why are earthquakes common at transform boundaries?
Plates sliding past each other build up stress → sudden release causes earthquakes.
What modern technology measures the movement of tectonic plates?
GPS (Global Positioning System).
Why should scientists consult Traditional Owners before fieldwork?
To respect cultural knowledge, protect sites, and gain informed consent.
Explain the differences between intrusive and extrusive igneous rocks.
Intrusive igneous rocks form underground, where magma cools slowly, allowing large crystals to grow (e.g., granite).
Extrusive igneous rocks form at the Earth’s surface, where lava cools quickly, so crystals are small or not visible (e.g., basalt, pumice).
Why does a pendulum not return to its starting height after swinging?
Some mechanical energy is transformed into heat and sound due to friction → total useful energy reduces.
What drives the movement of tectonic plates?
Mantle convection caused by heat from Earth’s core.
Why was Wegener’s idea rejected at first, and what evidence later supported it?
He couldn’t explain how continents moved. Later: seafloor spreading + magnetic striping + plate tectonics gave the mechanism.
How do the mantle and core differ, and how does the core create Earth’s magnetic field?
Mantle = semi solid/silicate rock; Core = iron–nickel. Movement of liquid metal in the outer core generates the magnetic field.