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TOPIC TWO

PLATE TECTONICS

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VOLCANOES

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INSIDE THE PLANET

Colour and label the diagram below. The thickness of each layer will

be given to you to add.

COLOUR SCHEME; Inner core- RED.

Outer core – ORANGE

Mantle - BROWN

Crust – GREEN and BLUE

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Pangea…….how the Earth came to be.

Clues: 1. Fossils of the land and fresh water dinosaur Mesosaurus are found in South

America and Africa.

2. A fossilized plant, Glossopteris, is found in Africa, Australia, India, South

America and Antartica

3. Labyrinthodont fossils are found in Southern Africa and Australia

4. Kannemeyerids are found in North America, South America, Asia and Africa

5. Warm weather plant fossils are found in Antartica

6. Evidence of glaciers can be found in tropical and temperate zones

7. Similar rock structures on different continents: Appalachian mountains are very

similar to mountains in Greenland and western Europe; Eastern South America and

western Africa have similar rocks.

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DIFFERENT TYPES OF VOLCANOES

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Parts of a volcano

After reading the following definitions, label the parts of the

volcano in the worksheet given below.

Magma – Molten rock beneath Earth’s surface.

Parasitic Cone – A small cone-shaped volcano formed by an accumulation of

volcanic debris.

Sill – A flat piece of rock formed when magma hardens in a crack in a volcano.

Vent – An opening in Earth’s surface through which volcanic materials escape.

Secondary Vent – A second, smaller opening on the side of the volcano

Flank – The side of a volcano.

Lava – Molten rock that erupts from a volcano that solidifies as it cools.

Crater – Mouth of a volcano – surrounds a volcanic vent.

Conduit – An underground passage magma travels through.

Summit – Highest point; apex

Throat – Entrance of a volcano. The part of the conduit that ejects lava and

volcanic ash.

Ash – Fragments of lava or rock smaller than 2 mm in size that are blasted into

the air by volcanic explosions.

Ash Cloud – A cloud of ash formed by volcanic explosions. ( also called a Py-

roclastic cloud)

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Volcanoes have 3 main categories: active, dormant, and extinct.

An active volcano is one which has recently erupted and there is a

possibility that it may erupt soon. A dormant volcano is one which

has not erupted in a long time but there is a possibly erupt in the

future. An extinct volcano is one which has erupted thousands of

hundreds of years ago and there is no possibility of eruption.

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CASE STUDIES....POMPEII 79AD

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CASE STUDIES.....KRAKATOA 1883

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CASE STUDIES….LAKE NYOS 1983

N.w. CAMEROON