l4 geology

Exam Q: Have a go….

“Describe and explain the difference between constructive and destructive waves, and how they affect the coastline.” [4marks]

How does geology influence erosion?

For the exam• You will have to be able to identify and explain

different landforms• They are split in to 2 groups:

Erosional landforms (created by erosion), e.g. headlands, cliffs, caves, etc.

Depositional landforms (created by deposition), e.g. beaches, spits, etc.

Make a prediction

• Sketch what you think will happen to this coastline + how it might look in 30’000 years

The geology of the coast affects how much it is eroded.

More resistant rocks (e.g. chalk) erode more slowly than less resistant rocks (e.g. clay, limestone)

This gives us BAYS

And HEADLANDS

Case Study : Jurassic Coast, Dorset

Prep for field trip next week

The Jurassic Coast

• The Jurassic Coast is a section of coastline in Southern England that shows geology over millions of years.

• The coastline first began forming 250million years ago

• Dorset shows the geology of the Jurassic period, between 200-140million years ago

Bays + Headlands at Swanage

Jurassic Coast

• Using the maps above + the laminated sheet, describe the location of Lulworth Cove. Use evidence from the map. [3marks]

N

Lulworthcove

• Lulworth Cove, Dorset, has a geology which is a mix of different rocks which have been tilted upwards over the years to become nearly vertical.

• Millions of years ago, a river rain through the rocks to the sea. This allowed sea water to enter + erode the rocks inland. First an opening in the limestone was eroded, then the sea reached the softer rocks of clay and sands and very quick erosion happened, spreading outwards.

• Eventually, the sea eroded far back in to the land until it reached the resistant chalk. Here the erosion slowed down. This made the perfect horseshoe-shaped bay you can see.

• Eventually this cove will erode further back and join another cove, to form one massive bay.

Lulworth Cove

Stair Hole, left. Lulworth Cove, Dorset right and below

Lulworth Cove is a horseshoe shaped bay that formed because the inland rocks are less resistant than the headland.

It is obvious how different rock types are affected at different rates.

The Durdle Door arch

•One of the features of the Jurassic coast is the Durdle Door arch.

•Why do you think it looks like this?

How does geology influence erosion?

O.S. Map of Ballard point, a headland on the Jurassic Coast.

What type of rock do you think the headland might be made from? …... ……….............................................. What effect does this have?............. …………………………………………

What type of rock do you think the headland might be made from? …... ……….............................................. What effect does this have?............. …………………………………………

What type of rock do you think the bay might be made from? …………. .........................................................What effect does this have?............. …………………………………………

Geological map of Ballard point

The headland:Made of chalk (light green)

Resistant rock

The beach:Made of gault

clay (dark green) and silt (blue)

The bay:Made of soft clays (red + dark green)

and sand (pink)

Overlay map

Using the printed map, make an overlay map of the geology on tracing paper

1)On the printed O.S. Map, label the Headland, beach and Bay

2)On the tracing paper, shade the dark green, light green, red, pink and blue outlines to show the different geology

3)Label the light green outline chalk, red and dark green is clay, pink is sand, blue is silt

4)Stick the tracing paper over the O.S. Map as an overlay. Give it a title.

Geog.GCSE

• Page 27

• Make a neat annotated sketch of Diagram C

• Annotations should have ...................?

Old Harry Rocks and Ballard Down.

What landform is this?

What landform is this?

Old Harry Rocks

What landform is this?

What process might have

happened here?

Durdle Door Arch in Dorset

What landform is this?

What landform is this?

The Needles, Isle of Wight

What landforms are these?

Birchington-on-Sea

What landform is this?

Wave cut platform, Southerndown, Wales

ICT taskICT task• Using the internet, produce a powerpoint that answers these questions:

1) Where is the Jurassic Coast? (Include map and description)

2) What erosion processes are happening at Lulworth Cove? (name the processes)

3) What landforms can be found in the Jurassic Coast? (Include pictures and labels, e.g. Arches, caves, etc.) – TIP. Look at Lulworth Cove, Durdle Door, Swanage, Old Harry Rocks.

4) Why are some areas eroding more quickly than others? (Think of the geology)

5) How do people use the area?

When you have completed the task:

- Upload your project to www.slideshare.net.

- Log in to ‘My Slidespace’ with username geodebs, password geodebs

- Save your work on here for me to mark.

Homework

• Extended homework sheet

• This does not mean leave it to the last minute• Each week I want an update on what you have

found out so far.• This should be a long project• Due: