Rocks Meaning and Types of Rocks


Meaning of rocks
Types of rocks



Subject : 

Basic Science and Technology


Term :

Second Term



Week 8


Class :

Basic 5 / Primary 5


Previous lesson : 

The pupils have previous knowledge of water cycle and rain formation in their previous lesson


Topic :

Meaning of rocks
Types of rocks
Uses of rocks
Major landmark rocks


Behavioural objectives :

At the end of lesson, pupils should be able to:

  • Define rock .
  • Say how rocks are formed .
  • Mention types of Rocks .
  • List the importance and uses of Rocks .
  • Mention some major landmark rocks in Nigeria .



Instructional Materials :

  • Wall charts
  • Pictures
  • Related Online Video
  • Flash Cards
  • Textbooks
  • Workbooks
  • Water bottle
  • Sample rocks or stones

Methods of Teaching :

  • Class Discussion
  • Group Discussion
  • Asking Questions
  • Explanation
  • Role Modelling
  • Role Delegation


Reference Materials :

  • Scheme of Work
  • Online Information
  • Textbooks
  • Workbooks
  • 9 Year Basic Education Curriculum
  • Workbooks


Content :

What is a rock  ?

A rock is an aggregate solid composition of matters that are living things which is a collection of mineral grains that are held firmly together . Rocks are found in different shapes and sizes. Rocks are breakdown into small stones and pebbles by the action of sun, rains and chemicals. At times rocks are broken down into smaller units ,pebbles . shapes or sizes by weather conditions like sun , rain ,change in temperature , wind or ice . This process of breaking down of rocks is known as weathering .


How are Rocks Formed  ?

Rocks  are formed by physical changes such as melting, cooling, eroding, compacting, or deforming . These physical changes that affect how rocks are formed are also known as agents of weathering .



Types of Rocks 

  1. Igneous Rocks : These rocks are the end results of hot molten materials inside the earth that leaks to the surface and later cools off .This hot molten material inside the earth surface is known as lava. When it escapes to the surface of the earth, the lava solidified to form igneous rocks. This usually occurs when there is a crack on top layer of the earth surface. The crack on the top layer of the earth is called volcano. Igneous rock is therefore called fire formed. They can be light or dark in color. Examples of igneous rocks are basalt and granite.


Features of Igneous Rocks 

  • They usually do not react with acid
  • They are glassy in nature
  • They are very hard
  • The composition of igneous does not include any fossil deposit


2.  Sedimentary Rocks : Sedimentary rocks the most common form of rock found in earth surface. They are formed when igneous rocks are broken down by the action of wind and water. Silt, sand and pebbles formed from breaking down of igneous rock are settle down in layers and formed sedimentary rocks. They also contain plant and animal dead body decay know as fossil. Examples of sedimentary rocks are shale, slate, coal, limestone, sand stones etc


Features of Sedimentary Rocks 

  • They are formed by the accumulation and decomposition of organic particles of both plants and animals
  • They are always arranged in layers that are stratified .
  • They are formed from broken down of pieces of already exiting rocks like the  igneous rocks



3. The Metamorphic Rocks : These are the rocks that are formed or changed  because of heat or pressure . They are not made from molten rocks . They are do not melt but the minerals that they contain are chemically changed .These changes are caused by heat, pressure or chemical action below the earth surface. Examples of metamorphic rocks are slate and marble.


Features of Metamorphic Rocks 

  • They metamorphosed or changed from igneous rocks and sedimentary rocks
  • The chemical composition of metamorphic rocks have been altered by the exertion of heat or pressure
  • They are soft rocks that are used in the construction of roads


Uses of Rocks 

  • Rocks like limestones are used to produce cement
  • Rocks attract tourist and serve as places of visit to tourists
  • Precious stones like gold, marbles are all from rocks
  • Sedimentary rocks are used in the production of writing materials like chalk
  • rocks are used in the building of houses
  • Rocks are used in the building of bridges
  • They are used are ornament for body decoration and beautification
  • They are used in road construction
  • Marbles can also be used in making furniture
  • Marbles are used to make tiles
  • Coal is used as source of fuel
  • They are used in the construction of slabs in hospitals or police stations




Some Major Landmark Rocks in Nigeria 

  • Aso rock in Abuja
  • Olumo rock in Ogun state
  • Zuma rock in Niger state
  • Shares hill in Plateau
  • Kufena rock in Kaduna




The topic is presented step by step


Step 1:

The class teacher revises the previous topics


Step 2.

He introduces the new topic


Step 3:

The class teacher allows the pupils to give their own examples and he corrects them when the needs arise




The class teacher wraps up or conclude the lesson by giving out short note to summarize the topic that he or she has just taught.

The class teacher also goes round to make sure that the notes are well copied or well written by the pupils.

He or she does the necessary corrections when and where  the needs arise.



Evaluation . 

  • Define rock .
  • Say how rocks are formed .
  • Mention types of Rocks .
  • List the importance and uses of Rocks .
  • Mention some major landmark rocks in Nigeria




Prepare for the next lesson by reading about acid and base