Endogenous Processes and Associated Landforms
ENDOGENOUS PROCESSES AND
ASSOCIATED LANDFORMS
THE EVER CHANGING LANDSCAPE
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Earth’s surface is ever changing
Endogenous processess- interior of the earth
Mountains, plateaus and plains formed
Occurences of volcanoes and earthquakes
Processess- slow and sudden
Many areas rise or subside
NOTABLE CHANGES
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Breaking of Gondwanaland 120 mya
Indian peninsula started drifting towards north
Took present shape around 40 mya
Raising of Himalayas- present height during last
1 million years.
FORCES OF DIASTROPHISM
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Folding
Faulting
Uplift
Depression
– Act Very slowly
– Effects visible after thousands of years
• Two types of diastrophism
– Vertical forces
– Horizontal Forces
VERTICAL FORCES
• Continental rise and sink
– Upward forces- Uplift
– Downward forces- Subsidence
• Do not disturb the horizontality of rock layers
• At the most, layers may be inclined or tilted.
HORIZONTAL FORCES
• Mountain- building forces
• Act in a horizontal direction
• Disturb horizontal layers of rocks
– Compression- body pushed from opposite sides
– Tension- Rocks are pulled apart
FOLDING
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•
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Bending of horizontal layers of rocks
Tilting or twisting of rock strata
Caused by compression
Formation of series of crests and troughs
Anticlines & synclines
– Anticlines- limbs incline in different directions
– Synclines- limbs incline in same direction
TYPES OF FOLDS
• Symmetrical folds- both limbs equally bent, inclined at almost equal angles to the horizontal.
• Asymmetrical folds- one limb pushed too far, one side gradual slop, other side steeper
• Monoclinal fold- one fold is vertical
• Isoclinal fold- both sides are inclined in the same direction
• Recumbent fold- one limb is pushed over the other, both limbs are parallel to each other
• Overthrust fold- fracture occurs, one limb slides forward over the other limb.
FAULTING
• Result of tension
• Rock strata cannot withstand tension, breaks
• Displacement along the fault plane.
– Normal Fault- blocks
ASSOCIATED LANDFORMS
THE EVER CHANGING LANDSCAPE
•
•
•
•
•
•
Earth’s surface is ever changing
Endogenous processess- interior of the earth
Mountains, plateaus and plains formed
Occurences of volcanoes and earthquakes
Processess- slow and sudden
Many areas rise or subside
NOTABLE CHANGES
•
•
•
•
Breaking of Gondwanaland 120 mya
Indian peninsula started drifting towards north
Took present shape around 40 mya
Raising of Himalayas- present height during last
1 million years.
FORCES OF DIASTROPHISM
•
•
•
•
Folding
Faulting
Uplift
Depression
– Act Very slowly
– Effects visible after thousands of years
• Two types of diastrophism
– Vertical forces
– Horizontal Forces
VERTICAL FORCES
• Continental rise and sink
– Upward forces- Uplift
– Downward forces- Subsidence
• Do not disturb the horizontality of rock layers
• At the most, layers may be inclined or tilted.
HORIZONTAL FORCES
• Mountain- building forces
• Act in a horizontal direction
• Disturb horizontal layers of rocks
– Compression- body pushed from opposite sides
– Tension- Rocks are pulled apart
FOLDING
•
•
•
•
•
Bending of horizontal layers of rocks
Tilting or twisting of rock strata
Caused by compression
Formation of series of crests and troughs
Anticlines & synclines
– Anticlines- limbs incline in different directions
– Synclines- limbs incline in same direction
TYPES OF FOLDS
• Symmetrical folds- both limbs equally bent, inclined at almost equal angles to the horizontal.
• Asymmetrical folds- one limb pushed too far, one side gradual slop, other side steeper
• Monoclinal fold- one fold is vertical
• Isoclinal fold- both sides are inclined in the same direction
• Recumbent fold- one limb is pushed over the other, both limbs are parallel to each other
• Overthrust fold- fracture occurs, one limb slides forward over the other limb.
FAULTING
• Result of tension
• Rock strata cannot withstand tension, breaks
• Displacement along the fault plane.
– Normal Fault- blocks