Transcript Mountain Building

Mountain Building
 Mountains are significant relief features of the
second order on the earth’s surface.
 A mountain may have several forms:
1. Mountain ridge- system of long, narrow & high
hills. Slope of one side of ridge is steep other side
slope is moderate
2. Mountain range- system of mountains & hills
having several ridges, peaks, summits and valleys
3. Mountain system- It consists of different mountain
ranges of the same period.
4. Cordillera- It consists of several mountain groups
and systems.
Classification of mountains
Based on height
Low mountains
Rough mountains
Rugged mountains
High mountains
Based on location
Continental mountains
Oceanic mountains
Based on mode of origin
Relict mountains
Tectonic mountains
On the basis of height
On the basis of location
1. Continental mountains1. Low mountainsexamples- Applachians,
height ranges
western & eastern Ghats of
between 700- 1000 m. India.
2. Rough mountainsheight- 1000- 1500 m.
3. Rugged mountainsheight- 1500- 2000 m.
4. High mountainsheight- above 2000m.
2. Oceanic mountainsmountains below the
water surface are oceanic
mountains.
On the basis of mode of
origin
1. Tectonic mountainscaused due to tectonic
forces like tensile and
compressional forces
2. Relict mountainsexamples- Vindhayachal,
Aravallis, Satpura etc.
Plateaus
- Plateaus are significant relief features of the second
order.
- They cover around 33 % of the surface area of the
globe.
- Plateau may be defined as that upland which has
atleast one side of very steep slope and the upper
part is extensively and almost flat.
- Examples- Ranchi plateau, Shillong plateau etc.
Characteristics of a plateau
• From locational point of view, plateaux vary from one
place to another place. Some plateaux are surrounded by
hills & mountains, some are bordered by hills &
mountains on one side while they are bordered by plains
or coastal areas on the other side.
• Some plateaux are very extensive in areal context.
•
• Plateaux have flat and rolling top surfaces.
• Generally, the slopes of the side walls are very steep but
the top surfaces are more or less flat.
Origin and evolution of Plateaux
Plateaux are originated in a number of ways:• Due to downwarping of surrounded areas.
• Due to upwarping of some portion of an extensive landmass
by a few hundred metres in relation to surrounding ground
surface.
• Due to deposition of thick covers of basaltic lavas.
• Due to the transformation of extensive mountains into low
uplands having extensive rugged surfaces due to prolonged
denudation.
Classification of Plateaux
On the basis of mode
of origin
According to geographical
situation
coastal
Piedmont
Intermontane
Continental
According to size & shape
Dome shaped
Dissected
Step like
Flat topped
Rejuvinated
Fluvial
Glacial
Aeolian
Intermontane
Piedmont
Continental
According to stage
volcanic
of erosion
Young
Mature
Old
Plains
• Plains are flat areas with low height.
• Plains may be above or below sea level but
they cannot be higher than the surrounding
regions.
• They are characterized by almost flat surface
but it also becomes undulating because of
erosion.
• Plains are dominated by level to gentle slopes.
Origin and development of plains
• Most of the plains have been originated due to upliftment of
submerged landmasses due to diastrophic movements.
• Plains are formed due to filling of depressions with sediments,
which are created in front of the mountains during the
process of orogenesis.
• Extensive plateaux after prolonged denudation become
plains.
• Deposition of enormous volume of lavas over extensive area
gives birth to volcanic plains.
Classification of Plains
According to structural
characteristics
According to mode of origin
Diastrophic
Flat
volcanic
Undulating
Rolling
Erosional
Dissected
Depositional
According to location
Inland
Coastal