The process of breaking of rocks - Humus process called - Humification

1. WEATHERING
I PG MICROBIOLOGY
SRCW

2. INTRODUCTION
• The break down of rocks and other
materials on the earth’s surface -
WEATHERING
AFFECTS THE
SUBSTANCE
EXPOSED TO
THE
ENVIRONMENT
CONTINOUS
PROCESS
SLOW

3. TYPES
TYPES OF
WEATHERING
PHYSICAL CHEMICAL BIOLOGICAL

4. PHYSICAL WEATHERING
PHYSICAL
TEMPERATURE WATER WIND

5. A) TEMPERATURE
Differential
expansion &
contraction of
materials
MINERALS - ROCK
EXPAND- HIGH TEMP
CONTRACT – LOW
TEMP
INTERNAL TENSION
– BREAKING INTO
FINER PARTICLES
Exfoliation
ROCKS- MANY
LAYERS
TEMP CHANGES –
SEPARATION &
DISINTEGRATION
Frost action
TEMP CHANGE-
FREEZING POINT
RESULTS IN WATER
ACCUMULATION IN
THE ROCKS
PRESSURE 150
TONES
BREAKS THE ROCKS

6. B)WATER
RAIN
RUNNING
WATER
WAVE
ACTION
GLACIER
FORMATION

7. C)WIND
CAUSES ABRASION OF
EXPOSED ROCKS

9. CHEMICAL WEATHERING
CHEMICAL WEATHERING
SOLUTION
HYDROLYSIS
OXIDATION
REDUCTION
CARBONATION
HYDRATION

10. CHEMICAL WEATHERING
• SOLUTION • HYDROLYSIS
WATER REACTS
WITH THE
MINERALS IN
THE ROCK
Na,K,Ca,Mg -
LOST
ROCKS GET
EASILY
REMOVED
WATER +
STRONG BASE ->
HYDROOXIDES
WATER + WEAK
ACID + CO2 ->
CARBONATES
CLAY
FORMATION/
DESTRUCTION
OF ROCKS

12. • OXIDATION • REDUCTION
CHEMICAL WEATHERING
1
• ADDITION OF CO2 +
MINERAL COMPOUND
2
• WEAKEN THE ROCKS
3
• IRON, ALUMINIUM,
MANGANESE OXIDES &
SULPHIDES
1
• REMOVAL OF O2
FROM
MINERALS
2
• TAKES PLACE IN
DEEP ZONE –
WERE O2 IS
ABSENT

13. • CARBONATION • HYDRATION
CHEMICAL WEATHERING
CO2 + H2O ->
H2CO3
CARBONIC
ACID
WEATHERING
H2O CHEMICALLY
ATTACH TO ROCK
MATERIALS
HEMALITE + H2O
-> LIMONITE

14. BIOLOGICAL WEATHERING
• Microorganisms present on
rocks
• Lichens, bacteria, fungi
• In presence of moisture – the
organism release Carbonic acid
– corrodes the rock