The older alluvium of the Indo-Gangetic plain, which contains lime nodules called kankar, is known as
- A.Khadar
- B.Bhangar
- C.Karewa
- D.Terai
Correct answer
Explanation
The correct answer is B, Bhangar. Bhangar is the older alluvium occupying the higher terraces above the present flood level of the rivers, and its soils often hold calcareous concretions known as kankar. Option A is wrong because Khadar is the newer alluvium of the flood plains, renewed by fresh silt in almost every flood and therefore the more fertile of the two; the pair is the most repeated distinction in this chapter. Option C is wrong because Karewas are lake deposits of the Kashmir valley, of the same broad age but a different formation, and are known for the cultivation of saffron. Option D is wrong because the Terai is a belt of damp, marshy land south of the Bhabar at the foot of the Himalaya, defined by its water table rather than by the age of its alluvium.
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
Show answer
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
Show answer
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
Show answer
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
Show answer
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
Show answer
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.
Read the full explanation →