The lignite deposits of Neyveli in Tamil Nadu belong to which geological system?
- A.Gondwana system
- B.Tertiary system
- C.Dharwar system
- D.Archaean system
Correct answer
Explanation
The correct answer is B, the Tertiary system. Lignite, or brown coal, is a low-rank coal formed from vegetation buried relatively recently, and the Neyveli field of Tamil Nadu is a Tertiary deposit, as are the petroleum-bearing rocks of Assam and Gujarat. Option A is wrong because the Gondwana system, much older, carries India's bituminous coal in the Damodar, Mahanadi, Godavari and Wardha valleys; the trap in this question is to answer Gondwana simply because the question mentions coal. Option C is wrong because the Dharwar system is the metalliferous system of iron ore, manganese and gold. Option D is wrong because the Archaean rocks are the fossil-free gneisses and granites of the Basement Complex and contain no fuel at all. The rule to remember is that metals come from the oldest rocks and fuels from the younger ones.
Read the full article: Geological Structure and Rock Systems of India Notes
Practice Questions
View allAny natural mass of mineral matter that makes up the earth's crust is _____.
- A.Garbage
- B.Rock
- C.Stone
- D.Fossil
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In geology a rock is any natural aggregate of one or more minerals that forms part of the earth's crust, whether it is hard like granite or soft like clay, and rocks are classified as igneous, sedimentary or metamorphic according to how they were formed.
Read the full explanation →Almost the whole of India's coal reserve belongs to which rock system?
- A.Dharwar system
- B.Vindhyan system
- C.Gondwana system
- D.Cuddapah system
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From the Upper Carboniferous onwards, thick beds of plant material accumulated in troughs and freshwater basins on the Gondwana landmass and were buried under sandstone and shale, giving the coalfields of the Damodar, Mahanadi, Godavari, Son and Wardha valleys.
Read the full explanation →The diamond-bearing conglomerates of India, including those of the Panna area, occur in which rock system?
- A.Archaean system
- B.Vindhyan system
- C.Gondwana system
- D.Tertiary system
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The sandstones, shales and limestones of this Purana system, which stretch across central India into the Son valley, contain the conglomerate beds in which diamonds are found, and the Panna mines of Madhya Pradesh as well as the diamonds once traded from the Kurnool area are associated with them.
Read the full explanation →Which rock system of India is the richest in metallic minerals such as iron ore, manganese and gold?
- A.Cuddapah system
- B.Dharwar system
- C.Vindhyan system
- D.Deccan Trap
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Named after the Dharwar region of Karnataka, it is the oldest metamorphosed sedimentary system in India and is described as highly metalliferous, yielding iron ore, manganese, gold, copper, lead, zinc and mica; the Champion gneiss of the Kolar gold field belongs to it.
Read the full explanation →Marble is formed by the metamorphism of which rock?
- A.Granite
- B.Sandstone
- C.Limestone
- D.Shale
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Limestone is a sedimentary rock composed mainly of calcium carbonate, and when it is subjected to heat and pressure its grains recrystallise into the dense, even-textured rock called marble.
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