BASALT MINING: GEOGRAPHY

NEWS: Basalt mining work resumes at West Bengal’s Deocha Pachami coal block, activists allege crackdown by administration

 

WHAT’S IN THE NEWS?

The Deocha-Pachami-Dewanganj-Harisingha coal project in West Bengal has been halted due to protests from local villagers, who are concerned about environmental impacts and displacement. The project involves mining basalt and coal, raising issues of land use, pollution, and community welfare.

 

Basalt Mining:

  1. Definition of Basalt Mining
    • Basalt is an igneous rock formed from the rapid cooling of lava on the Earth's surface. It is dense, hard, and durable, making it highly valued for industrial applications. Basalt mining involves extracting these rocks from the Earth’s crust for use in various sectors, including construction, agriculture, and manufacturing. Basalt’s resistance to wear and tear, high compressive strength, and natural abundance make it a sought-after resource for many industries.
  1. Mining Methodology
    • Basalt is usually extracted through quarrying, which is the process of digging deep trenches or pits to reach the basalt beds. Quarrying is done through techniques such as open-pit mining, where large areas of land are excavated. Once the basalt is exposed, it is cut into blocks or broken into smaller pieces for use in construction or other industrial applications.
    • For larger-scale mining, drilling and blasting may be used to fracture the rock, and heavy machinery like excavators and loaders transport the material to processing plants.
  1. Environmental Impacts
    • Air Pollution: Basalt mining contributes significantly to air pollution due to dust created by the extraction process, as well as emissions from the machinery used. Additionally, the vehicular traffic in mining areas generates pollutants that affect air quality.
    • Dust: The quarrying process generates substantial dust, especially when unpaved roads are used for transporting the mined basalt. This dust can lead to respiratory issues for workers and nearby populations.
    • Air Quality Monitoring: Given the environmental risks, regular monitoring of ambient air quality is essential to assess the concentration of particulate matter and other pollutants. This helps mitigate health risks for the local population and ensures that mining operations comply with environmental standards.
    • Domestic Fuel Burning: In rural mining areas, local communities often rely on traditional cooking fuels such as wood or biomass. The combustion of these fuels leads to additional air pollution, compounding the environmental issues caused by mining operations.
  1. Carbon Sequestration Potential of Basalt
    • Basalt rocks have a unique property of naturally absorbing carbon dioxide (CO₂) from the atmosphere during their formation. Over geological time, the minerals in basalt react with CO₂, sequestering it in the form of carbonates, thus making basalt an effective natural tool for mitigating climate change.
    • Long-Term CO₂ Storage: By using basalt as a construction material, such as for tiles, slabs, or concrete, CO₂ can be locked within the rock, effectively storing it over the long term. This is a key benefit of basalt, especially when used in building materials for sustainable construction, as it can offset carbon emissions from other sources.

 

Applications of Basalt:

  1. Construction Material
    • Basalt is highly valued in construction due to its hardness, durability, and resistance to wear. It is used as building blocks, tiles, slabs, and aggregates. Its ability to withstand environmental factors like heat, moisture, and abrasion makes it ideal for structures exposed to harsh conditions, such as roads, bridges, and buildings in coastal or seismic zones.
    • In some regions, basalt is used for paving roads and walkways, providing an aesthetically pleasing, long-lasting alternative to other materials like concrete or asphalt.
  1. Agriculture
    • Natural Fertilizer: When basalt is crushed into fine particles and spread over soil, it acts as a natural slow-release fertilizer. The minerals in basalt, such as calcium, magnesium, and iron, are essential for plant growth. Over time, these nutrients are released, improving soil fertility and encouraging healthy plant development.
    • Soil Neutralization: Basalt helps neutralize acidic soils. In areas where the soil pH is low (acidic), basalt can raise the pH, making the soil more suitable for a wide variety of crops. This property is especially beneficial for regions where soil degradation has made agriculture more difficult.
    • Rejuvenating Weathered Soils: Over time, basalt can help restore the fertility of weathered and nutrient-depleted soils by providing essential trace elements and minerals. This rejuvenates the soil, increasing its productivity and supporting sustainable agriculture practices.
  1. Geogrid Meshes for Road Reinforcement
    • Basalt fibres are used to make geogrid meshes, which are employed in civil engineering projects, particularly for road reinforcement. These meshes help distribute loads across a road’s surface, thereby improving its structural integrity and reducing the chances of erosion and surface cracking.
    • Roads built with basalt-fibre-reinforced geogrids have a longer lifespan as they are more resistant to damage from traffic and weather. This makes basalt an excellent material for reinforcing highways, rural roads, and infrastructure in areas prone to heavy rainfall or high traffic loads.
  1. Thermal and Acoustic Insulation
    • Basalt fibres are also highly effective as thermal and acoustic insulators. Their high melting point and durability make them suitable for applications in buildings where heat resistance is critical, such as industrial facilities or residential homes in hot climates.
    • In addition to thermal insulation, basalt fibres are also used for acoustic insulation. By reducing sound transmission, basalt fibres improve the acoustic comfort of indoor spaces, making them popular in construction projects that require noise reduction, such as in urban areas, theaters, and office buildings.

 

Major Basalt Zones and Mines in India:

  1. Deccan Traps
    • The Deccan Traps is one of the most famous and extensive basalt regions in India, located primarily in the western-central part of the country. This region formed as a result of volcanic eruptions that occurred millions of years ago, and its extensive basalt layers are rich in minerals. The Deccan Traps are one of the world’s largest volcanic provinces and provide significant amounts of basalt for industrial use.
  1. Deocha-Pachami Coal Block
    • The Deocha-Pachami coal block is located in the Birbhum district of West Bengal and is India’s largest coal reserve. It is home to 12.31 billion tonnes of coal and basalt deposits, making it a significant mining site. Basalt from this region is used in various applications, while coal extracted from the area is a crucial energy resource.
    • However, the mining of both basalt and coal in the region has faced opposition from local communities. Protests have erupted due to concerns over environmental degradation, displacement of communities, and the potential loss of agricultural land, highlighting the tension between industrial development and local community rights.
  1. Rajmahal Basalts
    • The Rajmahal Basalts are located in the Rajmahal Hills of Jharkhand, stretching into parts of the Bengal Basin. This region has vast basalt deposits and is known for its volcanic history. Rajmahal Basalts are rich in minerals and are important both for mining and scientific studies related to volcanic activity and mineral deposits.
  1. Bombay Area Basalts
    • The basalt formations in the Mumbai region, including the islands of Bombay (Mumbai), Salsette, and Trombay, belong to the Upper Deccan group. These rocks were formed from volcanic eruptions millions of years ago and continue to be a source of basalt mining. The geological significance of the Bombay Area Basalts is considerable due to their age and the role they played in shaping the region's landscape.

 

Challenges and Controversies:

  • The Deocha-Pachami-Dewanganj-Harisingha (DPDH) coal project has been facing a halt due to renewed protests from local villagers. These protests are driven by concerns about the environmental impact of the project, including deforestation, soil erosion, and air pollution. Additionally, villagers are worried about the displacement of local communities and the loss of livelihoods from mining activities. This scenario highlights the challenges of balancing industrial development with the rights of local populations and environmental sustainability.

 

Source: https://www.thehindu.com/news/national/west-bengal/basalt-mining-work-resumes-at-west-bengals-deocha-pachami-coal-block-activists-allege-crackdown-by-administration/article69303376.ece