Which of the following rock systems in India is the latest one?

The correct answer is D (Gondwana). Gondwana rocks are the youngest of the four, spanning roughly the Carboniferous to the Cretaceous (about 300 to 66 million years ago), and they hold most of India's coal.

• Dharwar is Archaean, among the oldest rock systems in India, and is known for its greenstone belts and gold and iron ore.
• Cuddapah is a Proterozoic (Purana) system in the Cuddapah basin of Andhra Pradesh, far older than Gondwana.
• Vindhyan is also Proterozoic (Purana), lying in the Vindhyan basin of central India, and is older than the Gondwana sequence.

The core concept is the stratigraphic sequence of Indian rocks: Archaean, then Purana (Proterozoic), then Gondwana (Palaeozoic-Mesozoic), followed by Tertiary. For Mains GS-I, Gondwana coal-bearing rocks explain India's coal reserves in the Damodar, Mahanadi and Godavari valleys, which links directly to the economic geology and energy questions.

Trap: Aspirants pick Vindhyan because it is the most familiar name, but the Purana rocks are all Proterozoic and older than Gondwana.