RAS question
Mica deposits in Rajasthan are mainly found in:
Correct answer: (A) Bhilwara and Ajmer.
In Rajasthan, mica deposits are mainly found in Bhilwara and Ajmer districts.
Explanation
Mica in Rajasthan is tied to pegmatite zones, with the main deposits in Bhilwara and Ajmer, in a belt extending from Bhilwara towards Jaipur within the Aravalli region. The Journal of Scientific Research, Banaras Hindu University describes pegmatite deposits in south-central Rajasthan, located mainly in the Jawaja and Rajgarh areas of Ajmer and the Gangapur and Jahazpur areas of Bhilwara, with muscovite present in the pegmatites. That makes Bhilwara and Ajmer the only option matching both the district pair and the pegmatite context behind Rajasthan's mica deposits.
Why the other options are wrong
- (B) Jaisalmer and Barmer are desert districts, while the main mica deposits are in the Bhilwara-Ajmer pegmatite belt.
- (C) Kota and Jhalawar are in the Hadoti region, which is not the main mica-bearing district pair.
- (D) Jodhpur and Nagaur are not major mica-producing areas; Bhilwara and Ajmer are the main districts.
Concept
This tests district-wise mineral distribution in Rajasthan Geography, with mica linked to pegmatite belts rather than broad physiographic regions. RAS repeats this concept because mineral questions often turn on matching a resource to its correct district cluster.