Competitive Exams: Folded Mountains
Folded mountains are formed due to folding of crustal rocks by compressive forces generated by endogenetic forces coming from within the earth. Its features
- They are found in great height
- Highest and extensive
- The width is less than height
- Arrow-like shape
- Faults are common cause of mountain uplift and faults in turn are due to shrinking of the crust
- Fossilsare being found
- Highest peaks are found in folded mountains
- Folded mountains are the youngest on the surface of the earth
- Basically found in the form of sedimentary rocks
- Have been Phanerozoic formed in long and shallow seas: Geosyncline (k); Are generally formed in arc shape having one side concave slope and the other convex slope
- Are found along the Archean margins of the continents facing ocean; Young Fold Mountains: Himalayas, Alps, Rockies, Andes
Old Fold Mountains
Pennines, Appalachians, Cape Ranges of South Africa, Great Dividing Ranges of A-ustralia.
Oldest: Scotland, Norway. Asia: Himalayas (8848 m); Arakana Yoma; Sulaiman; Hindukush; Zagros; Elburz; Pontus; Taurus; Kunlun; Karakoram (8611 m). Europe: Caucasus (5630m); Balkan; Carpethian; Alps (4810m); Dinaric Alps.
mass by a few 100 m. for eg. Western Patlands of Ranchi and Palamu (India) -Jharkhand.
Due to the deposition of the lava (volcanic), e. g. Dexcan trap, Entream of Ireland Columbian plateau (USA), Mahabalsstuvar and Panch gani. It is formed due to depo sition of basaltic lava
Due to the adjoining areas which are not folded, but are raised during the process of mountain building, eg. Cumber-land plateau to the west of Apalachian mountains
Because of the marginal sediment of geo-syncline are folded into parallel ranges, eg. Tibetan plateau between Kunlun and Tienshan, and Himalayas, Iranian plateau between Zagros and Elbruz mountains, Anatolian plateau between Pontus and Taurus mountains (Turkey)
Erosional or dissected plateau: Thick deposits of loose materials of wind also form plateau. Loess plateau of China is the best example. Classification of plateaus: There are ten types of plateaus. According to mode of origin: Simple plateau & complex plateau
Plateaus formed by exogenetic factor
It is of three types:
Glacial plateau: Examples are-Garhwal plateau, Greenland plateau, Marg of Kashmir.
Aeolian plateau: Examples are-Potwar (Pak) and Loess (China) plateaus
Fluvial plateau: It is formed due to the rivers. Examples are-Bhandar, Kashmir, Rewa, Rohtas and Panna plateaus.
Plateaus formed by endogenetic factors
It is of the following types:
Intermontane plateau: Features of these plateau are: Highest and most extensive plateau on the globe; It is caused by upwarping of the middle portion of geosyn-cline, known as median mass; Example: Tibetan plateau: Highest (5000 m) and most extensive (20, 64, 000 sq. Km.) plateau of the world. It is also called the ‘roof of the world’ It is surrounded by: Kunlun mountain: North-Himalayas: South-Kunlun and Himalayas: West-Chinese mountain: East Many rivers originate from this plateau in different directions: Southern plateau region: Indus and Brahmaputra rivers; Eastern plateau region: Hwangho, Yangtze, Salween and Mekong rivers; Northeast plateau region: Tsaidan swamps. [NOTE: The endogenetic forces cause high mountains than exogenetic forces. ] Mexican plateau: It is surrounded; by: West: Sierra Madre Occidental Mt. Range; East: Sierra Madre Oriental Mt. Range; The average height near Mexico city is 2250 m (7410 ft.) and decreases to 1216 m (4000 ft.). near the international border with USA. Plateau of Bolivia and Peru (South America): The Peruvian plateau is surrounded by Cordilera Central ranges and Cordillera Occiden-tal ranges in the east and west respectively. The average height is 3648 m (from sea-level, 12000 ft.). LakeTiticaca, a fresh water lake, comes out of it.
Gobi plateau in Asia Iranian and Tarin basin Columbian plateau Great basin
Piedmont plateau: It is formed at the foot hillzone of extensive mountains.