STRUCTURE
OF A FOLD.
The
peak of a fold is called an anticline. The bottom part of a fold is called a
syncline. The sides of a fold are the limbs. The anticlines stand as hills and
syncline as valleys.
TYPES
OF FOLDS
SYMMETRICAL
FOLD-
limbs are equal. Equal pressure comes from either side.
ASYMMETRICAL
FOLD-
Pressure is greater from one side. One limb is steeper than the other.
OVERFOLD- One
limb is pushed over the other. OVERTHRUST
FOLD/THRUST FAULT/NAPPE- Pressure causes the strata to fracture.
One side of the fold slides along the line of fracture called a fault LANDFORMS
ASSOCIATED WITH FOLDINGFOLD
MOUNTAINS The anticlines form ridges and synclines for valleys. Slopes
are steep and the mountain peaks are sharp and jagged. Almost all fold mountain
ranges are along plate boundaries. Effect
of fold mountains on people Tourism
can be an important activity especially snow skiing.Hydroelectric power stations can be found in fold mountains
because of high rainfall and steep slopes.Agriculture is limited to sheep and cattle rearing because of the steep
slopes.Population densities are low
in these regions.
FAULTING
A fault is a crack which forms in rocks as a result of
continuous tension and compression.
Faulting is caused by forces of compression or tension. Fault
line is a line along the surface of the Earth where a fault occurs.
TYPES
OF FAULTS
NORMAL
FAULT- This is caused by forces of tension. REVERSE
FAULT- Is caused by forces of compression. TRANSFORM/TEAR
FAULT- Tearing forces cause rocks to move past each other
laterally.
When tectonic forces are working and plates are pushed
together, the rock layers are put under great pressure and get
compressed. This pressure may make the rocks to bend into
folds.
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