Skip to main content

Geomorphology: Mountains

NOTE: Magma is molten rock below Earth's crust. Lava is magma that has reached the earth's surface.
A mountain is a large landform that stretches above the surrounding land in a limited area, usually in the form of a peak. Types of mountains:
1. Fold Mountains:
They are formed when two continental plates or one continental and one oceanic plate move towards each other at a convergent plate boundary. When the two plates collide the sedimentary deposits along the edges of Continental plates are forced to fold and hence folded mountains are formed. e.g. Himalyas.
Image result for fold mountains
2. Block mountains:
They are formed due to faulting. They are not true mountains as they are formed by differential settlement of land mass. There is no actual upliftment taking place as in case of fold mountains. Middle part of any land mass gets  lowered resulting into relatively raising of adjoining landmasses or Lowering of landmasses on either sides resulting into relatively raising of middle landmass. Block mountains are surrounded by faults on side of rift valleys or grabens. The uplifted part is called Horst and the depression is called Graben. e.g. Great African Rift valley.
Image result for block mountains

3. Volcanic mountains:
When a continental and an oceanic plates move towards each other at a convergent plate boundary, the oceanic plate subduct beneath continental plate because oceanic plate is denser. Due to high temperature below continental crust the oceanic plate melts and turns into magma. This magma is forced to come to the surface. When this magma reaches the earth's surface it cools down it formsrocks and eventually form Volcanic mountains. e.g. Mt. Fiji in Japan.
Related image

4. Dome mountains:
Formed when molten rock or magma pushes its way up under earth's crust. The magma does not erupts to the earth's surface but just pushes up the overlaying rock layers. e.g. Adirondack mountains of Australia.
Image result for dome mountainsImage result for dome mountains

5. Residual mountains:
They are formed from already existing mountains which are reduced by agents of denudation like water, air, ice etc. e.g. Mt. Monadnock in USA.
Image result for residual mountains


Comments

Post a Comment

Popular posts from this blog

Universe and the Earth: Universe consists of millions of Galaxies. Galaxy is a gravitationally bound system of solar systems, stars, stellar remnants, interstellar gas, dust and dark matter. The name of our Galaxy is Milky Way Galaxy. Age of Universe is said to be 13.7 billion years. Structure of Universe: 1. Galaxy: Large group of many Solar Systems. On basis of shape there are 3 type of galaxies:  i. Spiral  ii. Elliptical  iii. Irregular. 2. Solar System: Solar system is the collection of 8 planets, asteroids, kuiper belt, dwarf planets, meteoroids, comets and interplanetary dust with Sun at the centre. There are mainly 3 theories regarding origin of Universe: 1. Big bang theory: It was proposed by George Lemaitre. According to this theory the Universe is formed due to the expansion of a hot, condensed single point called 'point of Singularity'. Initially the Universe permeated energy. Some of this energy is transformed into particles like Hydroge...
Post a Comment
Read more

Geomorphology

Geo means earth, morpho means form, and logy means description. So Geomorphology is the study of earth, its landforms and various process, forces responsible for their formation. Based on the region of action these forces are classified into 2 types- Endogenetic and Exogenetic Forces. 1. Endogenetic forces act inside the Earth's crust. Objective of these forces is to create relief features on Earth's crust. It is further divided into Diastrophic and Sudden Forces. Diastrophic forces act slowly and are of 2 types- Epeirogenic forces and Orogenic forces. Epeirogenic forces are related to Continent. They act in vertical direction. This causes upliftment or subsidence of continent. Orogenic forces are related to mountains. They act in horizontal direction and can be tensile, compressive and shear. In Tensile forces plates move away from each other. In compressive forces plates move towards each other. In Shear forces plates slides past each other. Sudden forces act sudden...
Post a Comment
Read more