Soil Formation
 Soil is the top layer of the earth’s surface
 It varies from place to place depending on
 Geology ,climate, time etc
 Formation of soils
 Formed mainly through the weathering of geological materials
 Most irish soil comes from 15 thousand years ago when last ice sheet of glaciation melted
 Deposited glacial drift around Ireland
 Except west and the mountains
 After ice age climate improved and forests grew
 Added organic matter to soils
 True soil formation took place
 Formation factors
 The parent material the soil is on
 May be solid bedrock/glacial material
 Exposed to weathering/erosion leading to soil formation
 The area and landscaoe the soil is formed on
 The weather/climate of the area
 Surrounding organisms
 Trees, animals, plants
 Length of time
 Human effort
 Weathering is the process which rocks are broken down to smaller pieces
 Physical weathering
 Material broken down by temperature changes
 Frost,wind/water erosion and drying
 Chemical weathering
 Material broke down through chemical reaction
 Acid rain breaks down rock
 Carbon dioxide + water = carbonic acid (acid rain)
 Biological weathering
 Organisms break rocks down by physical and chemical means
 Carbon dioxide from plants mixes with rainwater making acid rain
 Roots break rocks as they grow
 Climate
 Weathering of rocks depends on weather
 Lots of water in ireland
 Water dissolves and removes various consitutents
 Called leaching
 Makes soils acidic
 topography