UNIT 6. EARTH’S STRUCTURE

UNIT OBJECTIVES To learn what the Earth is like. To understand the Earth’s changes. To learn about the Earth’s dynamics and rock

formation.

A DESCRIPTION OF THE EARTH

LAYERS OF THE EARTH

BIOSPHERE

ATMOSPHERE

HYDROSPHERE

GEOSPHERE

THE RELIEF

LAND RELIEF

SUBMERGED RELIEF

The emerged parts

(Continents and islands)

Mountain ranges

Plains

Continental

platformsAbyssal plains

Ridges

Trenches

Oceanic extensions with a continental

shelf.The ocean floor.Underwater mountain rangesDeep narrow depressions

ACTIVITIES1. Match:a) Biosphere 1-All the gases on the Earthb) Atmosphere 2-It’s made of rocksc) Hydrosphere 3-All the water on the planetd) Geosphere 4-All the living things on the planet2. Complete the diagram

3. Fill in the blanks:a) The emerged zones of the geosphere are called______ and________b) ________ __________are formed by mountains whicj lie along a large area.c) _____________ are formed by flat areas.d) The___________ __________ are areas at a lower level that the landforms around them.

THE LAYERS OF THE GEOSPHERE

THE CRUST THE MANTLE THE CORE

-The outer layer.-Solid hard rocks

Oceanic crust

Continental crust

-The middle layer.

-Malleable and molten rocks

-The deepest layer.

-It’s made of iron and nickel

Outer core

Inner core

Molten rocks

Solid rocks

It creates the

oceans

It creates the

continents

EARTH STRUCTURE

THE LITHOSPHERE It’s made up of solid rocks. It’s formed by the Earth’s crust and the upper

part of the mantle. Two types:

Continental litosphere. Oceanic litosphere.

The litosphere is not a continous layer. It’s divided into fragments called litospheric

plates (tectonic plates) Plate boundaries are

Oceanic ridges Oceanic trenches Large mountain ranges

LITHOSPHERIC PLATES

ACTIVITIES4. True or false? Correct them.a) The Earth’s crust is made up of elastic rocks.b) The earths’s crust can be continental or oceanic.c) The mantle is the thinnest layer of the geosphere.d) The core is made up of the outer core which is solid, and the inner core which is molten.5. Write the name of all the tectonic plates.6. Write down the name of two continents which are almost completely on a single plate.

THE EARTH’S INTERNAL HEAT The internal heat is called geothermal

energy. It increases with depth. The convection currents:

The hot rocks from the deep mantle rise to the surface.

The cold rocks from the upper mantle sink to the deeper zones.

ACTIVITIES7. Fill in the blanks:The Earth’s internal energy is called______ _______ and it creases with______.This energy produce some cyclic displacements called_______ _______, in which very hot rocks from the ______ mantle become less______ and they rise to the________, while the rocks in the ______ mantle which are ______ sink to the deeper zones.

ROCK FORMATIONTYPES OF ROCKS

MAGMATIC METAMORPHIC

SEDIMENTARY

Volcanic rocks

Plutonic rocks

Lava solidifies quickly on the surface. Tiny

crystals.

Magma solidifies slowly inside the crust.Big crystals.

Formed by

magma

Formed by crushed rocks by

pressure and temperature

Formed by atmospheric

and hydrospheric dinamics

- The sediments accumulate and are compressed.

- They can contain fossils.

MAGMATIC ROCKS Examples of Volcanic: Basalt, Obsidian,

Pumice Example of Plutonic: Granite, Diorite, Gabbro

METAMORPHIC ROCKS Examples: Slate, Marble, Schist

SEDIMENTARY ROCKS Examples: Sandstone, Limestone,

Conglomerate

ACTIVITIES8. Match:a) They can contain fossils 1) Volcanic rocksb) They cool down very quickly 2) Plutonic rocksc) They have been exposed to 3) Sedimentary rocksstrong pressure and temperature 4) metamorphic rocksd) They cool down very slowly9. Answer the questions:a) What rocks are formed by the action of inner dynamics of Earth?b) What rocks are formed by the action of the external dynamics of Earth?c) What is the name of the layers where sedimentary rocks are usually found?d) Where are plutonic rocks formed?

10. Julia was walking in the country and she picked up a rock. This rock was from part of a Wall of rock where several layers could be seen. She realized that the rock had the shape of a snail on it. What type of rock was it? Explain your anwer.11. Which layer is it?a) It’s the thickest layer of the geosphere.b) It’s made up of molten metals.c) It’s the coldest and thinnest layer.d) This layer is made up of metals and it’s solid.12. True or false? Correct them.a) The lithosphere is made up of the crust and the mantle.b) Spain and China are located on the same tectonic plate.c) Plate boundaries coincide with large landformsd) The USA and Brazil are on the same tectonic plate.

13. Match:a) Ridges 1) Large fragments of lithosphereb) Geosphere 2)Underwater mountain rangesc) Lithosphere 3) The solid part of the Earthd) Tectonic plates 4) Formed by the crust and upper mantle.

14. Match:a) Slate 1) Volcanic rocksb) Sandstone 2)Metamorphic rocksc) Granite 3) Sedimentary rocksd) Pumice 4) Plutonic rocks