Categories: Lesson Notes

SS1 First Term Geography Lesson Note – Rocks

The content is just an excerpt from the complete note for SS1 First Term Geography Lesson Note – Rocks. Check below to download the complete DOCUMENT

WEEK 9 & 10          

TOPIC: Rocks

CONTENT:

  • Meaning of rock and types of rocks.
  • Mode of formation of rock types.
  • Characteristics of rock types.
  • Importance of rocks to man.

Sub – Topic 1: Definition and types of rocks.

Definition of Rock    

A rock is any solid substance that forms part of the earth crust. This solid substance may be hard, like granite or even be soft like mud. In other word, rocks are aggregates of minerals, that is, a combination of different minerals.

The most common rocks and their minerals include;

ROCKS          MINERALS
Limestone quart, feldspar, micas
Sandstone quart, calcite, feldspar
Granite feldspar, augite

Types of Rock

There are three major types of rocks according to their origin, mode of formation and physical appearance. They are

  1. IGNEOUS ROCKS

Mode of formation:

These rocks are formed from the cooling and solidification of molten rock or magma from the earth beneath. They are crystalline in nature examples are Basalt and Granite.

Igneous rock could be divided into two, namely: Intrusive or plutonic igneous rock and Extrusive or Volcanic Igneous rock

Intrusive Igneous rocks are rocks which solidified deep in the crust and they are only seen on the surface after a prolong erosive action. Examples are granite, diorite and gabbro.

Extrusive Igneous rocks are rocks that formed when the molten rock or magma are ejected and poured on the earth’s surface as Lavas. These rocks do not contain fossils. Example is Basaltic rock and they can be located in North Eastern part of Nigeria.

CHARACTERISTICS OF IGNEOUS ROCKS

  1. These rocks are crystalline in nature
  2. They are non- stratified rocks i.e. they do not occur in layers.
  3. They are resistant to erosion and are usually hard and impervious.
  4. They do not contain fossils.

SEDIMENTARY ROCKS

Mode of formation:

These rocks are formed from the accumulation of sediments either by water, ice or wind. They are derived from other pre- existing rocks such as igneous rocks. They are laid in layers or strata. These rocks are said to be stratified rocks only when they become harder in nature by compressional forces.

To gain full access to the note: DOWNLOAD FILE

Sunday

Share
Published by
Sunday

Recent Posts

XTR 102 Theory Questions: Magnetic Relay and Fuse Ratings

100 Level Department Of X-Ray Technicians exam questions and detailed answers. Download the answers in…

5 hours ago

XTR 102 Theory Questions: Precision – Errors In Radiography

100 Level Department Of X-Ray Technicians exam questions and detailed answers. Download the answers in…

5 hours ago

XTR 102 Theory Questions: Electrical Symbols – Functions Of General Fuses In X Ray Department

100 Level Department Of X-Ray Technicians exam questions and detailed answers. Download the answers in…

7 hours ago

XRT 101 Theory Questions: Stages Of Human Dentition

100 Level Department Of X-Ray Technicians exam questions and detailed answers. Download the answers in…

8 hours ago

XRT 101 Theory Questions: Teeth As A Component Of Oral Cavity – Structure Of Teeth

100 Level Department Of X-Ray Technicians exam questions and detailed answers. Download the answers in…

8 hours ago

XRT 101 Theory Questions: Anatomy of the Mouth and Functions of the Tongue

100 Level Department Of X-Ray Technicians exam questions and detailed answers. Download the answers in…

8 hours ago