geography rocks and wheathering

Question 1

what exactly is rock?​

Answer 1

Rock is a mixture of minerals.​

Question 2

what is a mineral

Answer 2

A mineral is a natural compound. It has a chemical name and a formula, like the compounds in science – but we use its geological name.​

Question 3

what is geology

Answer 3

Geology is the study of the Earth, the materials of which it is made, the structure of those materials, and the processes acting upon them. ​

Question 4

describe sedimentary rocks

Answer 4

colourful
rough texture
forms in layers
reacts to weathering and erosion

Question 5

describe igneous rocks

Answer 5

resistant to erosion and weather
hard
shines when polished

Question 6

describe Metamorphic rocks

Answer 6

soft texture
resistant to weather
hard wearing

Question 7

examples of sedimentary rock

Answer 7

sandstone chalk
limestone
shale

Question 8

examples of igneous rock

Answer 8

obsidian volcanic ash

basalt granite

Question 9

examples of metamorphic rock

Answer 9

marble schist

slate

Question 10

how are sedimentary rocks formed

Answer 10

Sedimentary rocks are formed from sediments that have settled at the bottom of a lake, sea or ocean, and have been compressed over millions of years. ​

Question 11

how are metamorphic rocks formed

Answer 11

Metamorphic rocks have been subjected to tremendous heat and/or pressure, causing them to change into another type of rock

Question 12

how are igneous rocks formed

Answer 12

Igneous rocks are formed by magma cooling from the molten interior of the Earth.​

Question 13

extrusive igneous rock

Answer 13

form from lava cooling at the surface of the Earth.

Question 14

intrusive igneous rock

Answer 14

form from magma cooling underground, often relatively deep in the Earth.​

Question 15

weathering

Answer 15

Weathering is the breaking down of a rock by the action of things in its environment e.g. heat, cold, rain, plants, chemicals etc. ​​

Question 16

erosion

Answer 16

Erosion is the wearing away and removal of rock stone and soil by rivers waves wind and glaciers

Question 17

Physical weathering

Answer 17

caused by the effects of changing temperature on rocks, causing the rock to break apart.

Question 18

Freeze-thaw weathering (physical)

Answer 18

occurs when water continually seeps into cracks, freezes and expands, eventually breaking the rock apart.

Question 19

Exfoliation weathering (physical)

Answer 19

occurs as cracks develop parallel to the land surface a consequence of the reduction in pressure during uplift and erosion.

Question 20

Solution weathering (chemical)

Answer 20

removal of rock in solution by acidic rainwater. In particular, limestone is weathered by rainwater containing dissolved CO2, (this process is sometimes called carbonation)

Question 21

chemical weathering

Answer 21

caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.

Question 22

Hydrolysis weathering (chemical)

Answer 22

the breakdown of rock by acidic water to produce clay and soluble salts.

Question 23

oxidation weathering (chemical)

Answer 23

the breakdown of rock by oxygen and water, often giving iron-rich rocks a rusty-coloured weathered surface.

Question 24

Biological Weathering

Answer 24

Living organisms contribute to the weathering process

Question 25

burrowing animals weathering ( biological)

Answer 25

(moles and rabbits) can also make cracks bigger.

Question 26

Lichens, algae and mosses weathering (biological)

Answer 26

can produce weak acids which open cracks in rock and expose them to chemical and mechanical weathering.

Question 27

Plants put down roots weathering (biological)

Answer 27

through joints or cracks in the rock in order to find moisture. As the plant grows, the roots gradually prize the rock apart.

Question 28

rock cycle

Answer 28

The Earth’s rocks do not stay the same forever
continually changing because of processes such as weathering, erosion and large earth movements.
The rocks are gradually recycled over millions of years.

Question 29

What is the Geological Timescale

Answer 29

It is a record of the forms and geological events in earth’s history

Question 30

Rock Cycle Order

Answer 30

See powerpoint / geography book

Question 31

How did scientists develop the geological time scale

Answer 31

Scientists develop the timescale by studying rock layers and fossils worldwide

Question 32

What helps to determine the divisions of the geological timescale

Answer 32

Radioactive dating help to determine the divisions of the geological timescale