Block mountains are created when large areas are broken and displaced vertically. The uplifted block is called Horsts and the lowered blocks are called graben.

What are Block Mountains?

• Block mountains, also known as fault-block mountains, result from tectonic forces causing significant blocks of the Earth’s crust to break and shift.
• They take shape when the crust undergoes stretching, triggering the creation of extensive faults that cause crustal blocks to either drop or rise.
• Block mountains stand as upright land sections positioned between two faults or flanking the sides of a valley or canyon gap.
• The formation of block mountains is primarily associated with tectonic activities.
• Under the influence of tensional forces, the Earth’s crust can experience extension and fracturing, leading to the emergence of significant faults.
• As these blocks travel along the faults, certain portions experience uplift, while others may subside.
• The elevated blocks, confined by the faults, are termed “horsts,” while the sunken blocks between horsts are known as “grabens.”

There are two basic types of block mountains:

• Tilted block mountains have one steep side contrasted by a gentle slope on the other side.
• Lifted block mountains have a flat top and extremely steep slopes.

Examples of block mountains –

Block Mountains Examples in India

India is known for its diverse and varied topography, and there are several examples of block mountains in the country. Block mountains are formed when large sections of the Earth’s crust are uplifted along faults or fractures. Here are some examples of block mountains in India:

• Aravalli Range: The Aravalli Range, stretching across the states of Rajasthan, Haryana, and Gujarat, is one of the oldest fold mountain systems in the world. It is formed by a series of block mountains and is known for its rich mineral resources.
• Vindhya Range: The Vindhya Range, located in central India, is a complex mountain system that includes block mountains. It separates the Indo-Gangetic plains from the Deccan Plateau and is known for its scenic beauty.
• Satpura Range: The Satpura Range, located in central India, is a series of block mountains that run parallel to the Vindhya Range. It is characterized by rugged terrain, deep valleys, and dense forests.
• Eastern Ghats: The Eastern Ghats, running along the eastern coast of India, comprise several block mountains. They extend from Odisha in the north to Tamil Nadu in the south and are known for their scenic landscapes and waterfalls.
• Western Ghats: The Western Ghats, also known as the Sahyadri Range, is a UNESCO World Heritage Site and consists of several block mountains. They run parallel to the western coast of India and are famous for their biodiversity and lush green forests.
• Dhauladhar Range: The Dhauladhar Range, located in the Indian state of Himachal Pradesh, is a part of the larger Himalayan mountain system. It consists of block mountains and is known for its snow-capped peaks, deep valleys, and scenic beauty.

Characteristics of Block Mountains

• Block mountains, resulting from large-scale faulting in the Earth’s crust, form due to tensional forces creating fractures or faults. This process causes some blocks to rise as horsts and others to sink as grabens, with steep slopes often characterizing their rugged appearance.
• Adjacent rift valleys, being elongated grabens or down-dropped segments of the Earth’s crust, are typically found near block mountains due to the recent tectonic activity responsible for their formation.
• Unlike fold mountains, associated with compressional forces, block mountains originate in regions experiencing tensional tectonic forces, resulting from the pulling apart of the Earth’s crust. These mountains often exhibit a linear or rectangular shape, mirroring the orientation of the faults that gave rise to them, and frequently feature a substantial presence of uplifted sedimentary rock layers.

Significance of Block Mountains

1. Biodiversity Hotspots: Block mountains foster diverse ecosystems due to their varying altitudes, microclimates, and isolation, leading to the evolution of unique flora and fauna.
2. Hydrological Features: Rift valleys associated with these mountains create basins that accumulate precipitation, forming lakes and rivers, which play a vital role in local water resources.
3. Climate Influence and Resource Utilization: Block mountains serve as natural wind barriers, impacting local climate patterns with rain shadow effects and orographic rainfall. The fertile valleys between these mountains are conducive to agriculture, and the topography may offer renewable energy opportunities, such as hydroelectric power generation from rapid river flows.

Read Also :

• Plateau
• Landforms on The Earth
• Formation of Block Mountains
• Types Of Mountains