Introduction to the UK and Coasts (More information) Flashcards
How are sedimentary rocks formed?
Formed from sediments that have settled at the bottom of a lake, sea or ocean, and have been compressed over millions of years
What are some examples of sedimentary rocks?
Sandstone, limestone and chalk.
What are properties of sedimentary rocks?
Layers and intact fossils.
How are igneous rocks formed?
Created by volcanic activity when magma or lava cools.
What are properties of igneous rocks?
Randomly arranged crystals and resistant.
What are examples of igneous rocks?
Granite and basalt.
How is metamorphic rock formed?
When sedimentary or igneous rocks are subjected to great heat or pressure deep underground.
What are examples of igneous rocks?
Shale and marble.
What are properties of metamorphic rocks?
Have crystals and can contain fossils.
What are the properties of UK upland landscapes?
Much harder, resistant rocks that have eroded at a much slower rate, such as igneous and metamorphic rocks.
What are properties of UK lowland landscapes?
Formed from younger, softer sedimentary rocks which are less resistant to erosion.
What is mass movement?
Where weakened rocks can collapse under the influence of gravity.
What is hydraulic action?
The sheer power of the waves as they smash against the cliff. Air becomes trapped in the cracks in the rock and causes it to break apart.
Name the 4 types of coastal erosion.
Hydraulic action, attrition, abrasion and solution.
What is abrasion?
When pebbles grind along a rock platform. Over time the rock becomes smooth.
What is attrition?
When rocks that the sea is carrying knock agaisnt each other, and the rocks break apart to become smaller and more rounded.
What is solution?
When sea water dissolves certain types of rocks.
What are the four types of coastal transportation.
Suspension, solution, traction and saltation.
What is suspension?
Where sand and silt are carried in the flow of the water which makes the sea water look cloudy.
What is solution?
Where minerals are dissolved in the sea water and carried along.
What is traction?
Where large stones are rolled along by waves. (Mainly when there are high energy levels)
What is saltation?
Where small pebbles and stones are bounced along the sea bed by the waves.
What is depositon?
Where waves do not have adequate energy and drop the sand, pebbles and rock they are carrying.
When does deposition happen?
When the swash is stronger than the backwash. (Constructive waves).
What is longshore drift?
Sediment being moved along the coastline.
Describe the process of longshore drift (4)
Firstly, the prevailing wind blows waves carrying sediment onto the beach at an angle.
The backwash then carries the sediment back down the beach pependicular to the angle of the coastline under the influence of gravity.
This results in a zig-zag motion as sediment is transported along the coastline. Over time beaches will change shape because of this.
What are discordant coastlines?
Where there are alternating bands of hard and soft rock which are perpendicular to the coastline.