Mountains, Plateaus and Valleys
Complete Notes & Free Quiz

A mountain is a large landform that rises steeply above its surroundings, to a peak or ridge above 600 metres.

Mountains are classified on the basis of how they are formed into four types:
1. Fold mountains — folding
2. Block mountains — faulting
3. Residual mountains — weathering and erosion
4. Volcanic mountains — volcanic eruption

Fold mountains form when two plates collide and the soft sedimentary rocks between them bend or buckle up — this process is called folding, caused by compressional forces, over millions of years.

The Himalayas formed when the Indian Plate moved towards the Eurasian Plate, 40 to 50 million years ago. Other examples: the Alps (Europe), Andes (South America), Rockies (North America) and Urals (Russia).

Block mountains form by faulting — when rocks develop cracks, the side blocks are pushed down and the central block is pushed up. A block mountain with a flat top is called a horst.

Pakistan's major fault lines: the Chaman Fault (west), the Pab Fault (south) and the Main Mantle Thrust (north).

Residual mountains are the harder rocks left behind after long weathering and erosion wear away the soft rocks. Examples: Girnar hills, Nilgiri hills (India) and Sierra of Spain.

Volcanic mountains form when volcanoes erupt and pile layers of magma on the surface. Examples: Mount Vesuvius (Italy), Mount Fuji (Japan), Mount Kilimanjaro (Africa), Mount Pinatubo (Philippines) and Mount Erebus (Antarctica).

The Himalayas are like a wall separating the subcontinent from central Asia and extend nearly 320 km into Pakistan, splitting (south to north) into the Pir Panjal, Zaskar and Ladakh ranges. To the north lies the Karakoram and to its west the Hindu Kush.

Melting snow feeds the rivers: Jhelum (Pir Panjal), Indus (Zaskar & Ladakh) and Shyok (Karakoram). The Karakoram Highway — the highest paved road, the "eighth wonder of the world" — is the only overland link between Pakistan and China.

Pakistan lies at the boundary of two continental plates — the Indian Plate and the Eurasian Plate — which cuts through the centre of the country in a north-east to south-west direction. Because both plates have the same density, folding occurred and formed the Himalayas.

Convergent movement continues, so the Himalayas rise about 1 cm every year and earthquakes occur frequently. One of Pakistan's deadliest earthquakes struck Azad Jammu and Kashmir in 2005 (7.6 on the Richter Scale, about 79,000 dead).

A plateau is a raised, flat-surfaced landform, also called table land or a flat-topped mountain (about 500 m to thousands of metres high). Plateaus cover 45% of the Earth's land surface; the Tibetan Plateau (Central Asia, ~4,500 m) is the largest and highest — the "roof of the Earth".

Pakistan has two plateaus: the Potohar Plateau (Jhelum on the East, Indus on the West, Margalla Hills on the North, Salt Range on the South) and the Balochistan Plateau (west of the Sulaiman and Kirthar ranges).

A valley is a long depression surrounded by higher ground.

1. V-shaped valley — cut by rivers and streams into a narrow, steep "V" (a river valley), e.g. the Chitral Valley.
2. U-shaped valley — eroded and widened by glaciers into a broad "U" (a glacier valley).
3. Rift valley — an elongated lowland between two highlands formed by faulting, e.g. the East African Rift Valley system.

Chitral Valley (KPK) — a V-shaped valley at 1,128 m, famous for the world's highest polo ground at Shandur.
Kaghan Valley (KPK) — glaciers, lakes and waterfalls; visited in summer.
Murree — in the Himalaya (Pir Panjal) range, ~30 km NE of Islamabad, built in British rule.
Hunza (Gilgit Baltistan) — famous for its scenery and the Ladyfinger peak.
Bagrot (Karakoram range) — known for fruits and vegetables.
Naran (KPK) — 2,500 m above sea level.

People at high altitude face harsh conditions. Ahmed (mountains) farms on terraces and travels by jeep or donkey; Faisal (Potohar Plateau) grows wheat and cotton and works at the Attock oil refinery; Abdullah (Pir Panjal) does trans-human farming.

The Himalayas are rich in minerals (limestone, rock salt, marble) and, with the Karakoram, act as a barrier for the monsoon winds, affecting Pakistan's precipitation pattern.