The correct option is (d).
Explanation
Shale gas is an unconventional form of natural gas found trapped within shale formations, which are fine-grained sedimentary rocks. Unlike conventional natural gas, which resides in permeable reservoirs, shale gas is trapped in rocks with low permeability, requiring hydraulic fracturing (fracking) for extraction. The identification and assessment of these resources in India are overseen by agencies such as the Directorate General of Hydrocarbons (DGH).
Analysis of Regions
Various studies, including those by the United States Geological Survey (USGS) and Indian agencies, have identified several sedimentary basins in India as potential sources of shale gas. The Government of India has prioritized specific basins for exploration and assessment.
- Cambay Basin: Correct. Located in Gujarat, this is one of the primary basins identified for shale gas exploration due to its geological characteristics.
- Cauvery Basin: Correct. Located in Tamil Nadu, this basin is included in the list of prospective regions for shale gas and oil resources.
- Krishna-Godavari (KG) Basin: Correct. Located on the east coast (Andhra Pradesh), the KG Basin is a significant hydrocarbon province and is considered highly prospective for shale gas.
Consequently, all three regions mentioned possess identified shale gas resources.
Key Takeaway: The Ministry of Petroleum and Natural Gas has identified six basins as potentially shale gas-bearing: Cambay, Assam-Arakan, Gondwana, Krishna-Godavari, Cauvery, and the Indo-Gangetic plain.