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SubjectPaid lesson

Rocks

ClassNotes Team 2 MIN READUPDATED 5 JUL 2026

Geography SSS1 First Term

Week 8

Rocks

Performance Objective

The student should be able to:

  1. Types of Rock
  2. Characteristics of Rocks
  3. Mode of Formation of rock types
  4. Importance of Rock to Man

Definition of Rock

A rock is any solid substance that forms part of the earth’s crust. Rock is made up of minerals. The most common rocks and their minerals are:

Types of Rocks

Rocks are grouped based on their origin and mode of formation

  1. Igneous Rocks: They result from the eruption, cooling and solidification of magma from beneath the earth. They are usually crystalline. There are two types; plutonic (intrusive) igneous rock and volcanic (extrusive) igneous rock. Examples are basalt and granite.

Characteristics of Igneous Rocks

  • Igneous rock…