Explanations:Coal is a fossil fuel that forms from the remains of plants that lived millions of years ago. The type of coal found in a particular region depends on the geological age of the coal deposits and the conditions under which they were formed. Coal is classified into several types based on its age and the degree of carbonization, which affects its properties and uses.
The primary types of coal include lignite, sub-bituminous, bituminous, and anthracite. These types are further classified based on the geological periods during which they were formed. The Tertiary period, which spans from about 66 million to 2.6 million years ago, is a significant period for the formation of coal deposits in certain regions of the world, including parts of India.
In the northeastern states of India, such as Meghalaya, Assam, Arunachal Pradesh, and Nagaland, the coal deposits are primarily of the Tertiary type. This coal is relatively younger compared to other types like Gondwana coal, which is found in central India and formed during the Gondwana period (about 300 to 250 million years ago).
The Tertiary coal deposits in the northeastern states are formed from plant material that accumulated in swamps and bogs during the Tertiary period. Over time, these deposits were buried under layers of sediment, subjected to heat and pressure, and eventually transformed into coal. The specific conditions in the northeastern states, including the climate and geological processes, contributed to the formation of Tertiary coal deposits.
Understanding the geological context and the specific types of coal found in different regions is crucial for various applications, including mining, energy production, and environmental studies. The identification of Tertiary coal in the northeastern states is important for resource management and planning in these regions.