A; A journey through geological time

Question 1

Describes the Earth ‘s shape?

Answer 1

The Earth is almost spherical

Question 2

Describe briefly the layered structure of the Earth?

Answer 2

The layered structure of the Earth is a bit like a scotch egg

Question 3

What are the outer layers of the Earth divided up into?

Answer 3

Tectonic plates

Question 4

What does each plate contain?

Answer 4

Dense organic crust

Question 5

What can organic crust carry on top of it ?

Answer 5

Lighter continental crust

Question 6

How do plates move?

Answer 6

By very slow convection currents in the underlying currents

Question 7

What causes oceans to open slowly?

Answer 7

Movement of the tectonic plates cause oceans to open slowly

Question 8

What are geologists?

Answer 8

Scientists who study the earth

Question 9

How do geologists explain the past history of the earth?

Answer 9

By processes that can be observed today

Question 10

Describe how the continents have changed over the past 500 million years?

Answer 10

The continents have drifted and moved. Several 100 million years ago all the continents were together in one large land mass called Pangaea. Through continental drift the continents moved and continue to move today?

Question 11

Use your answer to 4 to explain why there are so many different rock types in Britain?

Answer 11

As the continents have moved different rocks were formed under different climatic conditions, so when Britain was part of Pangaea the weather conditions would have been much different than today and hence why the rocks are different.

Question 12

Explain how continents drift?

Answer 12

The core of the earth is hot, this causes the particles in the mantle to rise towards the crust, cooler particles will drop towards the hotter core and this is convection current. This movement of hot particles to the surface of the earth causes the movement of the continents.

Question 13

Name 3 sedimentary rocks?

Answer 13

Sandstone, Limestone, Conglomerate

Question 14

Describe how sedimentary rocks are formed (your answer must include the words weathering, erosion, deposition and burial/compaction).

Answer 14

Rocks undergo WEATHERING and get broken down into smaller parts, these small sediments can then be moved by water or wind in a process called EROSION. The sediments can then be DEPOSITED on the bottom of a lake/sea and then get covered by another layer of sediment in a process called BURIAL. These sediments are put under high pressure from the sediments above and are COMPACTED together to form sedimentary rock.

Question 15

What are the 4 clues in sedimentary rock that tell geologists the conditions that the rock was formed under?

Answer 15

Fossils
Shapes of the grains/sediments
Presence of shell fragments
Ripples on the surface of rocks

Question 16

If shell fragments were found in rock at the top of Mount Everest what does this indicate about the conditions it was formed in?

Answer 16

That those rocks were formed under water.

Question 17

What important clues do fossils give to the conditions rocks were formed in?

Answer 17

Geologist can tell whether it was an aquatic or dry land environment, the climate they were formed under, the type of environment and the age.