Unit 3: THE GEOSPHERE: minerals and rocks · a) Do most rocks consist of one or more minerals? b)...

Unit 3: THE GEOSPHERE: minerals and rocks

1. The geosphere

2. Minerals

3. Minerals and their properties

4. Rocks

5. Igneous and metamorphic rocks

1. THE GEOSPHERE VOCABULARY: depth (profundidad), crust (corteza), mantle (manto), consist of (formado de),

core (núcleo), huge (enorme), inner core (núcleo interno), outer core (núcleo externo), layer

(capa), thick (grueso), plain (llanura).

TYPES OF CRUST América – Atlantic Ocean – Europe

THE OCEANIC CRUST América – Atlantic Ocean – Europe

Activity 1. Activity 5 on page 28. Copy and

complete the table below in your notebook.

Activity 2. Activity 6 on page 28

2. MINERALS

There are amorphous minerals because their components do not have time to form geometrical shapes. Examples: opal.

VOCABULARY: fixed chemical composition (composición química fija), crystalline structure

(estructura cristalina), shape (forma), crystalline network (red cristalina), cool (enfriar),

amorphous (amorfo), quartz (cuarzo), feldspar (feldespato), mica (mica), ore (mena).

3. MINERALS AND THEIR PROPERTIES

Density Cleavages (exfoliación)

Fracture Hardness (dureza)

Colour Lustre (brillo)

Streak (raya) Magnetism (magnetismo)

Actividad 3. Copia en tu libreta los recuadros que aparecen en las páginas 62 y

63 de tu libro en español relacionados con estas ocho propiedades de los

minerales (densidad, exfoliación, fractura, dureza, color, brillo, raya y magnetismo).

Copia su definición y un ejemplo de cada una.

Actividad 4. Copia en tu libreta los diez minerales que forman la escala de Mohs

en orden creciente de dureza. Página 62 de tu libro en español.

Actividad 5. Haz un resumen del uso de los minerales en español. Solo hay que

escribir el mineral y su uso o usos. Páginas 64 y 65 de tu libro en español.

Density

Relationship between the mass and the volume of a mineral

(Relación que existe entre la masa del mineral y su volumen)

Mercury (Mercurio)

(13,5 g/cm3)

LOW NORMAL HIGH (baja) (alta)

Galena (Galena) (7 g/cm3)

Gold (Oro)

(19 g/cm3)

Sulfur (Azufre)

(2 g/cm3)

Cleavage (exfoliación)

When a mineral breaks into smooth, flat-sided fragments

(Un mineral tiene exfoliación cuando al golpearlo y romperlo presenta caras planas)

IN SHEETS (en láminas)

White mica (Moscovita o mica blanca)

Black mica (Biotita o mica negra)

Gypsum (Yeso)

Cleavage (exfoliación)

IN CUBES (en cubos)

Halite (Halita o sal común)

Galena (Galena)

Sylvite (Silvina)

Cleavage (exfoliación)

IN RHOMBOHEDRON (en romboedros)

Calcite (Calcita)

Fracture When minerals break into irregular pieces

(Los minerales que no se rompen presentan distintos aspectos, que en conjunto se denominan fractura)

Silex (Silex)

CONCHOID FIBRILLAR (Concoide) (Fibrilar o astillosa)

Asbestos (Asbesto)

Lustre (Brillo)

How the surface of the mineral appears when it reflects light

(Aspecto que presenta la superficie de un mineral cuando refleja la luz)

Pyrite (Pirita)

Olivine (Olivino)

METALLIC VITREOUS OR GLASSY GREASY

Gold (Oro)

Talc (Talco)

Colour

Sulfur (Azufre)

Olivine (Olivino)

Malachite (Malaquita)

Azurite (Azurita)

Graphite (Grafito)

Streak (Raya)

The colour of the mineral in powder form (El color del mineral pulverizado; es más característico y constante que el color del

mineral por lo que se utiliza para su identificación)

Gypsum (Yeso)

Pyrite (Pirita)

WHITE BROWN OR BLACK

HARDENESS (Dureza)

Resistance that the material has to being scratched (Resistencia que opone un mineral a ser rayado)

PARA MEDIR LA DUREZA SE UTILIZA LA ESCALA DE MOHS Esta escala está constituida por 10 minerales dispuestos en orden, de

forma que cada uno raya a los anteriores y es rayado por los

posteriores. Ejemplo: el apatito raya a la fluorita, calcita,

yeso y talco, pero es rayado por el feldespato, cuarzo, topacio, corindón y diamante.

https://www.youtube.com/watch?v=pv5h9K7eOwI

Actividad 3. Copia en tu libreta los recuadros que aparecen en las páginas 62 y 63 de tu libro en español

relacionados con estas ocho propiedades de los minerales (densidad, exfoliación, fractura, dureza, color,

brillo, raya y magnetismo). Copia su definición y un ejemplo de cada una.

Actividad 4. Copia en tu libreta los diez

minerales que forman la escala de Mohs en

orden creciente de dureza. Página 62 de tu libro

en español.

Actividad 5. Haz un resumen del uso de los minerales en español. Solo hay que escribir el

mineral y su uso o usos. Páginas 64 y 65 de tu libro en español.

4. ROCKS

Rock is a natural material that consists of minerals

Types or groups of rocks

IGNEOUS OR MAGMATIC ROCKS SEDIMENTARY ROCKS METAMORPHIC ROCKS

VOCABULARY: detrital sedimentary rock (roca sedimentaria detrítica), conglomerate

(conglomerado), sandstone (arenisca), clay (arcilla), saline rock, gypsum (yeso), limestone

rocks (rocas calizas), living beings, coal (carbón), oil (petróleo), remains (restos).

Most of rocks are formed by different minerals. Examples: granite, syenite.

Some rocks are formed by only one mineral. Examples: gypsum.

Sedimentary rocks Are formed from fragments of other rocks or the remains of living things or

dissolved salts that precipitate

Types of sedimentary rocks

Saline Detrital Limestone Consist mainly of calcite

Formed from fragments of other rocks

Are classified according to the size of their grains

Examples: conglomerates, sandstone and clay

Formed when dissolved salts in the water precipitate because

the water evaporates

Examples: halite and gypsum

Can be formed from the remains of living things (skeletons, shell…)

or through chemical processes (stalactites and stalagmites)

Examples: limestone, stalactites and stalagmites

Coal, oil and natural gas were formed millions of years ago from plant and animal remains. Some people think they are a type of sedimentary rocks but other people don’t agree with it.

Detrital sedimentary rocks

Clay (arcilla)

(grains smaller than 1/16 mm)

Are formed from fragments of other rocks. There are three types according to the size of their grains

Sandstone (arenisca)

(grains between 2 mm and 1/16 mm)

Conglomerates (conglomerados)

(grains greater than 2 mm in diameter)

How are detrital sedimentary rocks formed?

Saline sedimentary rocks

Gypsum (yeso)

Are formed when dissolved salts in the water precipitate because the water evaporates.

Halite (halita)

Limestone sedimentary rocks

Stalactites and stalagmites

Are formed from the remains of living things or through chemical processes (when calcite dissolved in water precipitates)

Limestones (calizas)

Fossil fuels

Oil (petróleo)

Are formed from plant (coal) and animal remains (plankton: oil and natural gas)

Coal (carbón)

Natural gas

Activity 6. Answer the following questions:

a) Do most rocks consist of one or more minerals?

b) How many types of rocks are there?

c) How many types of sedimentary rocks are there?

d) How can the sedimentary rocks be formed?

e) How do the grains differ between clays, sandstones and conglomerates?

f) What types of sedimentary rocks are formed by dissolved substances

that precipitate? And from the remains of living things? Write some

examples

g) Which is the main difference between a stalactite and a stalagmite?

5. IGNEOUS AND METAMORPHIC ROCKS

MAGMA Molten material from the Earth’s interior. It is a mixture of gases and minerals in a liquid state.

COOLS

Igneous or Magmatic rocks

TWO TYPES (depending on where magma or lava cools)

PLUTONIC rocks Are formed when magma cools

deep inside the Earth

VOLCANIC rocks Are formed when lava cools on the

Earth’s surface

VOCABULARY: Molten (fundido), granite (granito), syenite (sienita), gabbro (gabro), basalt

(basalto), pumice (piedra pómez o pumita), andesite (andesita), slate (pizarra), marble (mármol).

Differences between plutonic and volcanic rocks

1. Are formed when magma cools deep inside the Earth

2. Very slow cooling

3. Many crystals with similar sizes

PLUTONIC rocks VOLCANIC rocks

1. Are formed when lava from volcanoes cools on the Earth’s surface

2. Very fast cooling

3. Few crystals

Examples:

- Granite (the most common plutonic rock)

- Syenite

- Gabbro

Examples:

- Pumice

- Andesite

- Basalt (the most common

volcanic rock)

Activity 7. What is the main difference between magma and lava?

PLUTONIC rocks

Granite (granito)

(the most common rock in continental crust)

Syenite (sienita)

Gabbro (gabro)

VOLCANIC rocks

Basalt (basalto)

(the most common rock in oceanic crust)

Pumice (pumita)

Andesite (andesita)

METAMORPHIC ROCKS

Igneous and sedimentary rocks from deep inside the Earth

High pressure and high temperature

Clay

Metamorphic rocks In solid state

Examples: slate, marble and gneis

Very high pressure and high temperature

Granite

Limestone

SLATE (pizarra)

GNEIS

MARBLE (mármol)

Very high temperature and high pressure

Very high pressure and high temperature

PROGRESS CHECK

Activities 1 and 2 on page 34.

Activities 1 and 2 on page 35.

Actividad. PROPIEDADES DE LOS MINERALES con

ejemplos. El profesor la escribirá en la pizarra.

Activity. TYPES OF ROCKS and examples of each. The

teacher will write it on the blackboard.

Activity 8. How are metamorphic rocks formed?

Activities 12 and 13 on page 32.