Chapter 10: Rocks, Earthquakes, Tsunamis

Question 1

Igneous rocks

Answer 1

Igneous rocks are formed by volcanic activity. An igneous rock is formed when magma cools and solidifies

Question 2

Examples of igneous rocks

Answer 2

Granite in the mournes and basalt in the giants causeway.

Question 3

Sedimentary rocks

Answer 3

Sedimentary rocks are formed when bits of rocks or plants settle in layers and pressure compacts them together.

Question 4

Examples of sedimentary rocks

Answer 4

Limestone in Fermanagh and sandstone in the ards peninsula

Question 5

Metamorphic

Answer 5

Metamorphic rocks are formed when rocks are put under great pressure

Question 6

Examples of metamorphic rocks

Answer 6

Slate and marble

Question 7

Def. of fossils

Answer 7

Fossils are the remains of plants or animals buried in sediment

Question 8

Granite

Answer 8

If the magma cools down below the surface, it forms granite.

Granite has large crystals because the molten magma cools down slowly allowing large crystals to form

Question 9

Which mountain are formed from granite?

Answer 9

The mourne mountains in N.I

Question 10

Igneous rocks that form below the ground are described as:

Answer 10

Intrusive

Question 11

The two processes that can bring granite to the surface are:

Answer 11

Weathering and erosion - rocks above the granite are weathered away by wind, rain and ice.

Extrusion- if tectonic plates move, the granite rocks can be forced to the surface by a process of folding that pushes them up and through the rocks above them.

Question 12

Age of earth

Answer 12

The vast age of the earth (4500,000,000 years) has led to the concept of ‘deep time’. 4500,000,000 years is so much longer than any of the periods of time we are familiar with that it can be hard for us to imagine. Human history takes up only a fraction of the total history of earth.

Question 13

The age of rocks can be determined by….

Answer 13

Using radioactive elements such as ‘uranium’ and potassium in rocks. The proportion of daughter nuclei or elements found in these rocks allow scientist to work out how long it has Taken to decay. This is called ‘radio metric dating’.

Question 14

Age and structure of earth…

Answer 14

In 1648 Archbishop James Ussher calculated the age of the earth by adding together all the generations in the bible. He calculated that the creation of earth occurred in 4004BC, meaning the earth is around 6000 years old. However, fossils records suggested that the earth was much older than ushers estimate as creatures from millions of years ago were formed in rocks.

Question 15

The age of the earth is…

Answer 15

4.5 billion years