1. Soil Formation By :Reynaldo Thomas

2. Formation of Soil  Soil is an accumulation of tiny particles of rock which are formed when rocks are weathered.  Weathering is when rocks are broken up into smaller particles.  This happens by :  1.Physical Processes  2.Chemical Processes  3.Biological Processes

3. Physical /Mechanical Processes  This involves breaking rocks into smaller pieces.  Its chemical composition does not change in this process.  Physical processes occurs as a result of: 1.Water 2.Ice 3.Abrasion 4.Temperature change

4. Water and ice  Water expands when it form ice.  When the cracks in rocks collect water it will freeze in clod climate.  The ice will make the cracks bigger.  Hence pieces of rocks will fall away.

5. Abrasion  On the beach and in rivers, large rocks crash into each other.  Small particles of rock are chipped off.  Eventually the rocks get smaller and more rounded.

6. Temperature change  In extreme temperatures of the desert, the days are very hot and the nights are very cold.  The outer layer of rocks will crumble and fall away (like onion layers).  Minerals in the rocks will expand and contract as the temperature changes.  This process is called exfoliation.

7.  In regular strong winds particles of wear away larger rocks (abrasion).  This is the same effect when rubbing wood with sandpaper.

8. Chemical Processes  Weathering is also caused by different chemical reactions.  Weathering is also caused by chemical reactions.  The actions of carbonic acid, oxidation, dissolving and pH.

9. Oxygen  Oxygen oxidized minerals in rocks, making them more soluble (crumble more easily). Dissolving  Water dissolve minerals from rocks.  Forming crevices and hole.  Hence the rock structure getting weaker, making it easier for physical weathering.

10. Biological Processes  Biological processes is cause by plants, animals and microorganisms.  The roots of plant expand rock crevices, which force the rock apart.  Organic acids formed from dead leaves react with minerals in rock.

11.  Micro-organisms such as earthworms consume soil particles with food.  When passing out the particles they rubbed against each other and get smaller.