2. Exogenic (Exogenetic) The processes
which occur on earth’s surface due to the
influence of exogenic forces are called as
exogenic processes
The forces which derive their strength from
the earth’s exterior or originate within the
earth’s atmosphere are called as exogenic
forces or external forces.
Weathering, mass wasting, erosion, and
deposition are the main exogenic processes.
3. All the exogenic processes are covered
under a general term- denudation, which
means strip off or uncover.
The elements of nature capable of
doing these exogenic processes are
termed as geomorphic agents (or
exogenic geomorphic agents). E.g. the
wind, water, waves etc.
4. WEATHERING
Weathering is defined as mechanical
disintegration and chemical decomposition of
rocks through the actions of various elements of
weather and climate.
As very little or no motion of materials takes place
in weathering, it is an in-situ or on-site process.
There are three major groups of weathering
processes: (i) chemical-(due to air & water);
(ii) physical or mechanical;
(iii) Biotic factors.
5. MASS MOVEMENT
Movement of weathered material down a slope due
to gravitational force.
Soil creep: slow, gradual but continuous movement
of soil down the hills( damp soils)
Soil flow: soil saturated with water and acts like
liquid and soil flow happens
Landslides: large mass of soil or rock falls suddenly
on steep slopes such as mountain, cliffs
etc.Earthquake and volcanoes also leads to it.
6. LANDFORMS
Fluvial landforms and Cycle of Erosion –
Erosional Landforms and
Depositional Landforms
Glacial landforms
Marine landforms
Arid landforms
Karst landforms
7. FLUVIAL EROSION
The landforms created as a result of degradation
action (erosion) or aggradational work
(deposition)of running water are called fluvial
landforms.
The fluvial processes may be divided into three
physical phases – erosion, transportation and
deposition
8. Upper course
1.River capture-natural diversion of the
headwaters of one stream into the channel of
another, typically resulting from rapid headward
erosion by the latter stream
2.Rapids and waterfalls
13. GLACIAL LANDFORMS
Highland glaciation
1.Cirque or corrie- A glacially eroded rock basin
2. Aretes and pyramidal peak- High sharp pointed, steep sided
peaks
3. Bergschrund- forms where moving glacier ice separates from the
stagnant ice
4. U-shaped glaciated trough
5.Hanging valleys
6.Morains
16. GLACIATED LOWLAND
1.Roche moutonne- produced by action of
advancing ice, the smooth slope being on the
side of ice advance(abrasion) and the rough
slope on the other side
17. 2.Boulder clay-clay containing many large stones and
boulders
3.Drumlins- elongated hill in the shape of an inverted
spoon or half-buried egg
4.Outwash plains Made up of fluvio glacial deposits
18. ARID LANDFORMS
Arid regions are regions with scanty rainfall. Deserts and
Semi-arid regions fall under arid landforms.
Water Eroded Arid Landforms
19. Rill: In hill slope geomorphology, a rill is a narrow and shallow
channel cut into soil by the erosive action of flowing water.
Gully: landform created by running water. Gullies resemble large
ditches or small valleys, but are metres to tens of metres in depth
and width.
Ravine: a landform narrower than a canyon and is often the product
of stream cutting erosion. Ravines are typically classified as larger
in scale than gullies, although smaller than valleys.
Canyons: bigger in depth, steep walled eg: grand canyon
Badland Topography: in arid regions occasional rainstorms
produce numerous rills and channels which extensively erode weak
sedimentary formations.
: Chambal Ravines.
22. Mushroom rocks: also called rock pedestal or a
pedestal rock, is a naturally occurring rock whose
shape, as its name implies, resembles a mushroom.
Inselbergs: A monadnock or inselberg is an
isolated hill, knob, ridge, outcrop, or small
mountain that rises abruptly from a gently sloping
or virtually level surrounding plain.
23.
24. ARID DEPOSITIONAL LANDFORMS
Sand dunes:
Sand dunes are heaps or mounds of sand found in deserts.
Generally their heights vary from a few metres to 20 metres
but in some cases dunes are several hundred metres high and
5 to 6 km long.
Loess
In some parts of the world, windblown dust and silt blanket the
land. This layer of fine, mineral-rich material is called loess.
Extensive loess deposits are found in northern China, the
Great Plains of North America, central Europe, and parts
of Russia and Kazakhstan.
The thickest loess deposits are near the Missouri River in the
U.S. state of Iowa and along the Yellow River in China.
27. KARST LANDFORMS
Karst topography is a landscape formed from the
dissolution of soluble rocks such as limestone,
dolomite, and gypsum.
It is characterized by underground drainage
systems with sinkholes, caves etc.
28. LANDFORMS
Erosional-
1. Uvalas or valley sinks-small depression
2. Polje : It is large depression in a karst region with steep sides
and flat floor. It is drained by surface water sources
3. Swallow hole
4. Caves and Caverns: A natural cavity, chamber which leads
beneath the surface of the earth generally in a horizontal or
obliquely inclined direction
5. Blind valleys
6. Springs
Depositional –stalcite and stalagmite