residual mountains for 3 February 2026

Residual mountains are ancient landforms formed by the continuous erosion of old mountain ranges or plateaus over millions of years. They are created when weathering and denudation remove softer rocks, leaving behind hard and resistant rock structures. These mountains usually have rounded peaks, lower heights, and appear as isolated hills or small ranges. Examples include the Aravalli Range in India and the Ural Mountains, Scottish Highlands, and Scandinavian Highlands in the world.

Residual Mountains Formation

Residual Mountains also known as Circum-erosional or Relict mountains are formed through the long-term process of erosion and denudation, where external natural forces gradually wear down ancient mountain ranges or plateaus. Over time, softer rocks are removed, leaving behind hard and resistant rock structures as residual mountains.

• Origin from Ancient Mountain Ranges or Plateaus: Residual mountains were originally part of large fold mountains or elevated plateau regions formed by tectonic forces millions of years ago.
• Weathering of Rocks: Physical, chemical, and biological weathering processes break down rocks into smaller particles, weakening the mountain structure.
• Erosion by External Agents: Natural agents such as rivers, wind, glaciers, and rainfall remove weathered rock materials layer by layer, reducing the mountain’s height.
• Denudation Process: Continuous removal of surface material through erosion, transportation, and deposition gradually reshapes mountains into smaller remnants.
• River Dissection of Plateaus: Rivers cut deep valleys and separate plateau regions into hills and ridges, which later appear as residual mountains.
• Survival of Hard Rocks: Hard and erosion-resistant rocks like granite and quartzite remain intact after softer rocks are removed, forming the core structure of residual mountains.
• Gradual Reduction in Height and Size: Over long geological periods, erosion lowers the elevation and changes the rugged mountain terrain into smoother, rounded landforms.

Residual Mountains Characteristics

Residual mountains are ancient landforms formed after long periods of erosion and denudation that wear down older mountain ranges or plateaus. The key characteristics of the residual mountains are:

• Ancient Geological Formation: Residual mountains are among the oldest mountain landforms on Earth. They represent the remaining parts of once massive mountain ranges that have been reduced in height due to continuous erosion over millions of years.
• Rounded Peaks and Gentle Slopes: Due to prolonged weathering and erosion, residual mountains generally have smooth, rounded summits and less rugged terrain compared to young fold mountains like the Himalayas.
• Lower Elevation: These mountains usually have moderate or low heights because erosion gradually removes upper rock layers, reducing their overall size and elevation.
• Composed of Hard and Resistant Rocks: Residual mountains mainly consist of strong rocks such as granite, quartzite, and basalt, which resist erosion and remain standing after softer rocks are removed.
• Isolated or Fragmented Appearance: Many residual mountains appear as scattered hills or small mountain ranges surrounded by plains or plateaus, giving them a distinct landscape presence.
• Thin Soil Cover and Sparse Vegetation: Continuous erosion removes fertile topsoil, leaving rocky surfaces where vegetation is often limited.
• Evidence of Long-Term Erosion Processes: Residual mountains serve as geological records showing the impact of weathering, river erosion, wind action, and glacial activity over long time periods.

Residual Mountains in India

India contains several prominent residual mountain ranges that provide evidence of ancient geological activity and erosion.

1. Aravalli Range

The Aravalli Range is one of the oldest mountain systems in the world, stretching from Gujarat to Delhi. It represents the eroded remains of ancient fold mountains and contains important mineral deposits such as copper and zinc.

2. Parasnath Hills (Jharkhand)

Parasnath Hill is the highest peak in Jharkhand and is considered a residual mountain formed through long-term erosion. It is also a significant religious site for Jain pilgrims.

3. Nallamala Hills (Andhra Pradesh and Telangana)

These hills are part of the Eastern Ghats and are formed through plateau dissection by river erosion. They consist mainly of ancient sedimentary rocks.

4. Mahendragiri Hills (Odisha)

Mahendragiri is a residual mountain within the Eastern Ghats and is known for its geological and religious importance.

5. Javadi, Veliconda, and Palkonda Hills

These hill ranges in southern India are remnants of ancient plateau regions dissected by rivers and erosion processes.

Residual Mountains in the World

Residual Mountains are found across different continents, showcasing the universal impact of erosion on Earth’s surface.

1. Ural Mountains (Russia)

The Ural Mountains are among the oldest mountain ranges and form a natural boundary between Europe and Asia. They are heavily eroded remnants of ancient fold mountains.

2. Highlands of Scotland

The Scottish Highlands represent a classic example of residual mountains formed through long-term glacial and river erosion.

3. Scandinavian Highlands

Located in Northern Europe, these highlands are remnants of ancient geological structures shaped by glaciation and erosion.

4. Sierras de Europa (Spain)

This mountain range is formed from the erosion of older mountain systems and contains limestone formations shaped by weathering.

5. Mesas and Buttes (United States)

Mesas and buttes are flat-topped elevated landforms created when plateau surfaces are eroded by rivers and wind, leaving isolated residual hills.

UPSC CSE PYQs

Question: Which of the following mountains is considered a residual mountain? [2018]

1. A) Andes
2. B) Ural Mountains
3. C) Himalayas
4. D) Alps

Answer: (B)