RAS question
Delhi Supergroup rocks are found in which part of Rajasthan?
Correct answer: (C) NE Aravalli (Alwar-Jaipur).
Delhi Supergroup rocks in Rajasthan are found in the north-eastern Aravalli belt, especially around the Alwar-Jaipur sector.
Explanation
The Delhi Supergroup is linked with the north-eastern Aravalli belt, especially the Alwar-Jaipur sector. The official Alwar district hydrogeological atlas places Alwar in the north-easterly part of the Aravalli range and states that the district is covered primarily by rocks of the Aravalli and Delhi Supergroup. Delhi Supergroup formations in Alwar include quartzite, arkose, conglomerates, limestones or marbles, schist, slates and phyllites. These rocks occur in the NE Aravalli belt and include quartzite, marble and schist. Delhi Supergroup rocks in Rajasthan belong to the Aravalli geological belt, not to a broad plains, desert or plateau setting.
Why the other options are wrong
- (A) Southern plains are not the Delhi Supergroup setting in Rajasthan; the relevant setting is Aravalli metamorphic rocks.
- (B) The western desert is associated with younger rocks, not the Delhi Supergroup belt.
- (D) Hadoti plateau belongs to a different geological province and is linked with Vindhyan rocks.
Concept
Rajasthan's geological divisions distribute major rock systems across the Aravalli belt, desert, plains and plateau regions. In RAS preparation, physiography, minerals, groundwater and regional geology frequently depend on matching rock systems with their correct locations.