Rocks and landscape

Question 1

How are igneous rocks formed

Answer 1

By the cooling of molten magma underground (intrusive) or on the ground (extrusive)

Question 2

what are the characteristics of igneous rocks

Answer 2

Composed of interlocking crystals (they are said to be crystalline). Generally tough rocks and are resistant to erosion

Question 3

example of Igneous rocks

Answer 3

Basalt, andesite and rhyolite

Question 4

How are sedimentary rocks formed

Answer 4

formed by the compaction and cementation of sediments; usually deposited in the sea. Also includes organic material

Question 5

what are the characteristics of sedimentary rocks

Answer 5

Sedimentary rocks usually form layers called beds. They often contain fossils. although some rocks an be tough (e.g limestone), most are weaker than igneous and metamorphic

Question 6

Examples of sedimentary rocks

Answer 6

Sandstone, limestone, shale, clay and mudstone

Question 7

How are metamorphic rocks formed

Answer 7

Formed by the alteration of pre-existing igneous, sedimentary or metamorphic rocks by heat and/ or pressure

Question 8

What are the characteristics of metamorphic rocks

Answer 8

metamorphic rocks are also crystalline. They often exhibit layering (not beds) called cleavage (as with the rock slate) and banding. Metamorphic rocks tend to be very tough and resistant to erosion.

Question 9

examples of metamorphic rocks

Answer 9

Slate, gneiss

Question 10

What are the 3 types of weathering

Answer 10

Mechanical
chemical
Biological

Question 11

What is mechanical weathering

Answer 11

Also known as physical weathering, this involves the disintegration of rocks without chemical changes taking place. Often results in piles of angular rock fragments called scree found at the foot of bare rocky outcrops.

Question 12

what is chemical weathering

Answer 12

here, a chemical change occurs when weathering takes place. Rainwater, being slightly acidic, can slowly dissolve certain rock and minerals. Those minerals or particles unaffected by chemical weathering are usually left behind to for a fine clay deposit.

Question 13

what is biological weathering

Answer 13

this involves the actions of flora and fauna. Plant roots are effective at growing and expanding in cracks in the rocks. rabbits can be effective in burrowing into weak rocks such as sands

Question 14

What are the types of mechanical weathering

Answer 14

1. Freeze thaw

2. Exfoliation

Question 15

what is freeze thaw weathering

Answer 15

when water freezes in a crack or hole. The water expands by approximately 9% causing the rock to break off.

Question 16

what is exfoliation

Answer 16

This is when the outerlayer of the rock breaks of due t the constant, heating and cooling of the rock in warm environments. This is due to the rock being a poor conductor of heat, so only the outer layer expands and contracts

Question 17

what is solution

Answer 17

this is the same as sugar dissolving in tea and is caused by the rocks dissolving in the slightly acidic rain water

Question 18

What is carbonation

Answer 18

the dissolving of calcium carbonate, such as limestone and chalk. carbonation is responsible for forming some of the landforms associated with limestone landscapes

Question 19

what is a Batholith

Answer 19

A huge irregular shaped mass of intrusive igneous rock that only reaches the ground surface when the overlying rocks are removed

Question 20

What is impermeable rock

Answer 20

a rock that does not allow water through

Question 21

what is a tor

Answer 21

an isolated outcrop of rock on a hilltop, typically found in granite landscapes

Question 22

list some features of a granite tor

Answer 22

Horizontal joints formed by pressure release when the overlying rock were removed

rounded edges caused by chemical weathering

Vertical joints formed when the granite cooled

Enlarged joints caused by freeze thaw weathering