SOILSSOILS

ONE OF THE MOST IMPORTANT ONE OF THE MOST IMPORTANT SUBSTANCES IN THESUBSTANCES IN THE WORLDWORLD!!

SOILSSOILS

AGRONOMIST’S DEFINITIONAGRONOMIST’S DEFINITION

The loose cover of earth made The loose cover of earth made of minerals (sand, silt and of minerals (sand, silt and clay), water, air and organic clay), water, air and organic matter; is capable of matter; is capable of supporting plant growthsupporting plant growth..

How is soil formed?How is soil formed?

Try to picture the rocks that Try to picture the rocks that originally formed the outer originally formed the outer surface of the earth’s crust. surface of the earth’s crust. This the raw material of soil This the raw material of soil and is called and is called parent material.parent material.

What are the five factors of soil What are the five factors of soil formation?formation?

Parent materialParent material TopographyTopography ClimateClimate Life – biological, animal & (human)Life – biological, animal & (human) Time - absoluteTime - absolute

- relative- relative

Parent materialParent material

TopographyTopography

Climate - weatheringClimate - weathering

Mechanical weathering from windMechanical weathering from wind

LifeLife

TimeTime

How rapidly rocks break down How rapidly rocks break down depends on:depends on:

Physical, chemical and Physical, chemical and biological forcesbiological forces

The kinds of minerals the rock The kinds of minerals the rock containscontains

Rocks definedRocks defined

Rocks consists of any Rocks consists of any mineral or aggregate mineral or aggregate (clusters) of minerals that (clusters) of minerals that forms as a part of the earth.forms as a part of the earth.

Three categories of rocks:Three categories of rocks:

Igneous Igneous SedimentarySedimentaryMetamorphicMetamorphic

IgneousIgneous

Brought up from below in a Brought up from below in a molten conditionmolten condition

Has no evidence of bandingHas no evidence of bandingAll surfaces look the sameAll surfaces look the same

Igneous rockIgneous rock

Examples of igneous rocksExamples of igneous rocks

GraniteGranite

Another example of igneous rockAnother example of igneous rock

BasaltBasalt

Another example of igneous rockAnother example of igneous rock

ObsidianObsidian

Sedimentary RockSedimentary Rock

Sedimentary rock is a result from Sedimentary rock is a result from weathered weathered particles of rocksparticles of rocks that have that have been been deposited from suspensiondeposited from suspension transported by wind, water or ice and transported by wind, water or ice and is is cementing togethercementing together under under pressure.pressure.

Often forms in layersOften forms in layers

Sedimentary RockSedimentary Rock

Examples of sedimentary RockExamples of sedimentary Rock

Limestone – CaCO3Limestone – CaCO3

Another example of sedimentary rockAnother example of sedimentary rock

SandstoneSandstone

Another sedimentary rockAnother sedimentary rock

conglomerateconglomerate

Another sedimentary rockAnother sedimentary rock

ShaleShale

Metamorphic RockMetamorphic Rock

Metamorphic rock is a Metamorphic rock is a secondary rock that may form secondary rock that may form from Igneous rock or from Igneous rock or sedimentary rock as a result of sedimentary rock as a result of heat, pressure or chemical heat, pressure or chemical action.action.

Metamorphic rockMetamorphic rock

Examples of metamorphic RockExamples of metamorphic Rock

quartzitequartzite

Another example of metamorphic Another example of metamorphic rockrock

marblemarble

Another example of metamorphic Another example of metamorphic rockrock

slateslate

Another example of metamorphic Another example of metamorphic rockrock

schistschist

Another example of metamorphic Another example of metamorphic rockrock

gneissgneiss

What types of rocks do you find in What types of rocks do you find in Connecticut?Connecticut?

Eastern CT- mostly metamorphic rocks such as Eastern CT- mostly metamorphic rocks such as gneiss, schist and quartzite with some igneous rock gneiss, schist and quartzite with some igneous rock such as granite.such as granite.

Central CT – is low land consisting of red sandstone. Central CT – is low land consisting of red sandstone. The hiss in this low area consists of igneous rock, The hiss in this low area consists of igneous rock, such as basalt, which is also called trap rock.such as basalt, which is also called trap rock.

Northwestern CT – Sedimentary rocks such as Northwestern CT – Sedimentary rocks such as limestonelimestone

Western CT – Metamorphic rocks such as schist and Western CT – Metamorphic rocks such as schist and quartzite.quartzite.

How are complex rock surfaces How are complex rock surfaces broken down?broken down?

Sudden changes in temperature causes rocks to Sudden changes in temperature causes rocks to expand or contract which causes rocks to crumble and expand or contract which causes rocks to crumble and flake.flake.

Water finds its way into cracks and crevices.Water finds its way into cracks and crevices. Water in the cracks can change to ice and expand, Water in the cracks can change to ice and expand,

causing the rock to break into smaller fragments.causing the rock to break into smaller fragments. As the rocks are reduced, minerals combine with As the rocks are reduced, minerals combine with

water forming new compounds.water forming new compounds. Some minerals disolve and are washed away, while Some minerals disolve and are washed away, while

some like quartz and clay, become an important part some like quartz and clay, become an important part of the soil.of the soil.

How can parent material be moved How can parent material be moved from one place to another?from one place to another?

GlaciersGlaciers GravityGravity WaterWater WindWind Each time particles are moved, Each time particles are moved,

they may be further broken down they may be further broken down and sorted to size.and sorted to size.

Geological Classifications of soils are Geological Classifications of soils are based on how the soil was depositedbased on how the soil was deposited

CT Geological Soil classificationsCT Geological Soil classifications Glacial till – A mix of gravel, sand, silt and clay that Glacial till – A mix of gravel, sand, silt and clay that

was was deposited by ice with little or no water deposited by ice with little or no water

transportationtransportation..

Stratified driftStratified drift

Rock materials sortedRock materials sorted by waters from glaciers by waters from glaciers and and left in layersleft in layers as partially sorted. The finer as partially sorted. The finer particles, silt and clay, were generally carried particles, silt and clay, were generally carried off.off.

AlluviumAlluvium

Materials Materials moved by watersmoved by waters and later deposited and later deposited along stream beds. This is rich soil, great for along stream beds. This is rich soil, great for farming!farming!

LoessLoess

Mostly transported by Mostly transported by wind wind during dry during dry weather periods right after the melting of the weather periods right after the melting of the glacial ice.glacial ice.

GlaciolacustrineGlaciolacustrine

Very fine sand, silt and clay picked up by Very fine sand, silt and clay picked up by glacial action to glacial lakes. (layered with glacial action to glacial lakes. (layered with varied thickness)varied thickness)

Organic SoilsOrganic Soils

Plant material accumulated in shallow waters. Plant material accumulated in shallow waters. As As generations of plants diedgenerations of plants died they filled in they filled in saucer like depressions called peat (if saucer like depressions called peat (if identifiable) or muck (if impossible to identify.identifiable) or muck (if impossible to identify.