2.1 - North Antrim

Question 1

Order of layers:

Answer 1

Colonnade
Entablature 
Colonnade
Laterite
Basalt
Chalk

Question 2

Why are the colonnades permeable

Answer 2

Column jointing means there are cracks in between which water can get through

Question 3

How was column jointing formed

Answer 3

Tectonics

Lava cooled faster at top, creating cracks by contracting

Question 4

Describe the entablature

Answer 4

Made of basalt which is impermeable so water can’t get through

Question 5

What happens after water gets through the colonnade

Answer 5

Can’t get through entablature so builds up pressure as it accumulates, creates cracks, gets through those

Question 6

What happens after water gets through entablature

Answer 6

Erodes the laterite away since it’s soft/causes it to flow out
Upper material collapse into the space

Question 7

What happens after laterite

Answer 7

Reaches impermeable basalt layer which is very resistant, protecting chalk underneath

Question 8

How was tectonics responsible for lithology?

Answer 8

Lava will have flowed over and cooled quickly on the chalk to form basalt
Lithology responsibility

Question 9

Describe white rocks

Answer 9

Basalt layer on top partially

Sedimentary rock is hundreds of thousands of years old - more resistant as old

Question 10

How will have tectonics created White Rock

Answer 10

Distorted rock to form anticlines and synclines (WR are anticlines)
Then erosion of S to leave A