GEOMORPHOLOGY-
It is a tangle of Physics, Chemistry, Biology, and History. It may be defined as the scientific study of surface features of the Earth's surface involving the interpretative description of landforms, their origin, development, nature, and mechanism of the geomorphological processes which evolve the landforms.
An understanding of geomorphology and its process is essential to the understanding of physical geography.
MOUNTAIN SYSTEM-
# Mountains are significant relief features of the second order on the Earth's surface.
# Generally, the mountains are more than 1000m high.
# The mountains whose height is less than 1000m, called Hills.
# Mountain System refers to mountains formed in a single period, which includes many mountain ranges and groups of single mountains. Ex.Appalachian.
# Mountain range refers to mountains formed in the same age and with the same process but having structural differences arranged in narrow belts. Ex.Himalayan mountain range.
# Mountain groups are highlands composed of different mountains with an unsystematic pattern. Ex.Juan mountain group.
# Mountain Ridges are mountains formed due to local folding and faulting and rise abruptly from the adjoining region. Ex.Blue ridge mountains(USA)
TYPE OF MOUNTAINS-
Based on their mode of formation, there are four main types of mountains.
1. FOLD MOUNTAINS-
* Formed when a thickly bedded sedimentary layer is subjected to horizontal compressional forces for millions of years.The sediments get bent into up and down folds. This leads to the formation of anticlines and synclines.
* These are the highest and most extensive mountains of the world.
* TYPES OF FOLD MOUNTAINS:
(i) Young fold mountains- The Himalayas, The Alps, The Rockies, The Andes etc.
(ii) Mature fold mountains-The Pennines, The Appalachians, and the Cape range of south Africa were formed during the carboniferous age.
(iii) Old fold mountains-The high mountains of Scotland and Norway, the Sayan and the Stanovai mountains of Russia, and the Aravalli and the Mahadeo mountains of India.
2. BLOCK MOUNTAINS-
* These mountains are formed by tensional or compressional forces produced on the crustal part led to faulting.Tensional forces tend to pull the crust apart and develop the blocks that enclosed the fault looks like risen parts and are called Block mountains.
* It represents the upstanding parts of the ground between two faults or on either side of a rift valley or a graben.
* The Vosges in France, Black forest mountains in Germany, and the Sierra Nevada in North America are typical examples of block mountains.
3. DOME MOUNTAINS-
* Sometimes Earth's crust does not break into blocks but rises upwards as a result of Earth movements. In the region where it raises upwards, a dome-like structure is formed. They are called Dome mountains.
* The Henry mountain in North America is one such example.
* Volcanic mountains also looks like dome mountain as it is formed by the accumulation of ejected materials from fissures in the Earth's crust . The ejected materials flow from the vent in layers and form a conical peak. Volcanic mountains are often called mountains of accumulation.
4. RELICT MOUNTAINS-
* Relict mountains are the remnants of former old mountains and plateaus, which have been subjected to severe denudation, thus, exposing the base of mountains.
* Vindhyas, Aravallis, Satpura, Western Ghats, Eastern Ghats are examples of relict mountains.
Major Mountain Ranges
Range Location Length(km)
Andes South America 7200
Himalayan Asia 2400
Rockies North America 4800
Great Dividing Range East Australia 3500
Atlas Northwest Africa 2400
Western Ghats Western India 1610
Caucasus Europe 1200
Alaska USA 750
Alps Europe 1100