C3 Flashcards
Why do geologists study rocks?
to see how the Earth’s surface has changed.
What to geologists look at in rocks?
- how rocks form
- how they change
- when changes happened
How do geological changes happen?
by slow movements of tectonic plates
How do tectonic plates move?
by sliding past eachother, colliding or pulling apart.
What do plate collisions build?
mountain ranges, which errode over time.
What was the positioning of england, wales and scotland 600 million years ago?
England and Wales were separated from Scotland by ocean, and both were near the south pole.
What was Pangea?
a supercontinent which formed gradually when different continents drifted and crashed together.
What is britain made from?
rocks from different ancient continents.
Originally what was Britain nearer to which gave it a warmer climate?
the equator
What is formed as lava solidifies?
igneous rocks
What does the UK have due to conditional movement and climate changes?
many different rocks and raw materials
What do magnetic materials in the lava line up along?
the Earth’s magnetic field.
How can geologists date rocks and track the slow movements of continents?
using changes in magnetic patterns, linked to radioactive decay.
What evidence supports plate tectonic theory?
the slow movement of continens.
What are buried in the Earth’s crust?
Rocks
What are the three most important raw materials?
coal, salt, limestone
When the industrial revolution started, where was coal, salt and limestone found?
- coal in south lancashire
- salt in cheshire
- limestone in the peak district
What was the process of the formation of limestone while Britain was covered by sea?
- shellfish died forming sediments on the sea bed
- sediments compacted and hardened to form linestone, a sedimentary rock.
- tectonic plate movements pushed the rock to the surface
- gradually the rocks above were eroded away until the limestone was exposed.
When did coal first form?
in wet swampy conditions when plants like trees and furns died and became buried.
How did salt form in cheshire?
- Rivers brought dissolved salts into the sea
- Climate warming evaporated the water, leaving salt that mixed with sand blown in the wind.
- Rock salts formed and was buried by other sediments
What evidence have geologists found for limestone, coal and salt formation?
- coal contains fossils of the plants that formed it
- limestone contains bits of shell fragments from sea creatures.
- rock salt contains different-shaped water-eroded grains and wind-eroded grains.
What are the three uses of salts?
- in the food industry
- as a source of chemicals
- to treat icy roads in winter
How can salt be obtained?
- collecting and evaporating sea water
- mining underground deposits of rock salt
Why is rock salt spreaded on icy roads?
- the rock salt is insoluble but the sang in the rock salt gives grip
- it shows up so people know when the roads have been gritted
- the salt in solution lowers the freezing point, preventing ice forming as easily
How much does the cheshire rock salt mine mine a year?
a million tonnes
How can purer salt be obtained?
solution mining
