60
The Earth: origin and composition
33.
Find out the thicknesses of the different layers of
the Earth and order them from thickest to thinnest.
34.
Make a table to compare the characteristics of the
continental crust and the oceanic crust.
35.
Were all materials distributed according to their
density from the very beginning? Explain your
answer.
36.
Explain why the following statements are true or
false.
a)
The seismic method only allows us to know the
composition of the Earth’s crust.
b)
The Earth is made up of solid materials.
c)
The Earth’s crust has a uniform thickness of 50 km.
d)
Denser materials in the geosphere are found on the
Earth’s surface.
e)
The Earth’s mantle is located between the Mohorovičić
discontinuity and the Lehmann discontinuity.
f)
The Earth’s inner core is solid because the temperature is
lower than in the outer core.
37.
The following graph shows how seismic waves
move around the planet. Which seismic waves are
travelling at a higher speed? Which layers of the
Earth do they go through?
Minerals
38.
Which property of materials
does the image show?
39.
Describe four properties of minerals.
40.
Explain if an ice cube and coral used in jewellery
are minerals or not.
41.
Investigate and then copy and complete the table
in your notebook.
42.
According to the Mohs scale, what is the hardness
of a mineral that scratches orthoclase but is
scratched by quartz?
43.
Explain how to distinguish white quartz from
orthoclase, which is the same colour?
44.
Find out why the colour and streak of a mineral
isn’t always the same.
45.
Find out why pyrite is also referred to as ‘fool’s gold’.
Rocks
46.
Explain the three characteristics that are used to
classify rocks.
47.
Pumice is a rock that floats in water. Why do you
think this is? Is it a natural or an artificial rock?
Justify your answer.
48.
Copy the following terms in two columns in your
notebook and then match them.
A:
limestone, granite, clay, marble, basalt, chalk
B:
detrital sedimentary, non-detrital sedimentary, plutonic,
volcanic, foliated metamorphic, non-foliated metamorphic
49.
Are there any rocks which are not composed of
minerals? What type of rocks are they?
50.
When 1 kg of granitewas analysed in the laboratory
using different chemical processes they obtained
250 g of a white mineral, 300 g of another mineral,
almost black, and the rest was a grey mineral.
a)
What is the name of each mineral that composes granite?
b)
Which mineral corresponds to the grams of minerals
above?
51.
On an excursion, Ana found a rock that contained
a plant fossil that lived on Earth millions of years
ago. What type of rock do you think it was? Explain
your answer.
52.
Which rock forms quartzite after metamorphism?
What size are the grains of the original rock?
Speed of siesmic wave (km/s)
Depth (km)
0
Moho
Gutenberg Lehmann
Waves S
Mantle
Outer
core
Inner
core
Waves P
0
3
6
9
12
1000 2000 3000 4000 5000 6000
Mineral
Ore
Cassiterite
...
...
Lead
Hematite
...
...
Zinc
Chalcopyrite
...
CONSOLIDATION
