Coal deposits found in Northeast India belong to various geological ages, and their formation can be attributed to different periods spanning millions of years.
The geological history of coal in this region is fascinating, as it provides insights into the ancient landscape and environmental changes.
In this article, we’ll explore the geological age of coal found in Northeast India and the factors that contributed to their formation.
So, let us start!
- Gondwana Age Coal:
The primary geological age of coal in Northeast India is the Gondwana period, which dates back to about 300 million years ago. During this era, the landmasses of the southern hemisphere were part of the supercontinent Gondwana.
The coal-bearing sediments in this region were formed when the land was covered by lush tropical forests. Over millions of years, plant material accumulated in swampy environments and underwent a process of sedimentation and compaction, eventually leading to the formation of coal seams.
These Gondwana-age coal deposits are found in various states of Northeast India, including Assam, Meghalaya, Nagaland, Arunachal Pradesh, and parts of Manipur and Mizoram. The coals from these deposits are generally high in moisture and volatile matter and are considered sub-bituminous or lignite in terms of rank.
- Tertiary Age Coal:
In addition to Gondwana-age coal, some parts of Northeast India also contain Tertiary-age coal deposits, which are relatively younger, with an age ranging from 2 to 66 million years. These deposits are more recent compared to Gondwana-age coal. They were formed during the Tertiary period, characterized by a warm and humid climate.
Tertiary-age coal is primarily found in the region of Assam. The coal from this period is often classified as lignite and is known for its relatively high moisture content and low carbon content.
These coal seams formed in swampy environments, similar to their Gondwana-age counterparts, but the environmental conditions during the Tertiary period were different, influencing the coal’s composition and characteristics.
Formation Factors:
The formation of coal in Northeast India is closely linked to the geological processes that occurred during these ancient ages. During the Gondwana period, the land was characterized by extensive forests, which provided an abundant source of plant material.
The accumulation of this plant material in waterlogged, low-oxygen environments was essential for coal formation.
The Tertiary-age coal deposits, on the other hand, formed due to different geological and environmental conditions, such as tectonic movements and changes in sea levels. These factors influenced the type and quality of coal formed during this period.
Utilization and Significance:
Coal from Northeast India has been a valuable resource for the region, serving as a source of energy for both industrial and domestic use. It has played a pivotal role in the economic development of the states in this part of the country.
Furthermore, the geological age of coal is significant in determining its quality and energy content. Gondwana-age coal from the region is typically of sub-bituminous or lignite quality, which is used for power generation and in industries.
Tertiary-age coal is often lignite, suitable for thermal power generation.
In a nutshell, the geological age of coal found in Northeast India is primarily of Gondwana and Tertiary ages.
These coal deposits offer a glimpse into the ancient history and environmental conditions of the region.
Understanding the geological ages of coal is essential for the efficient utilization and conservation of this vital energy resource.