UPSC Prelims 2014 · Question 18 of 100
UPSC Prelims 2014 question on Coalbed Methane Shale Gas
- ExamUPSC CSE
- Year2014
- PaperGeneral Studies Paper I
- SubjectEnvironment and Ecology
- TopicMiscellaneous Environment and Ecology
- DifficultyMedium
- TypeStatement
With reference to two non-conventional energy sources called 'coalbed methane' and 'shale gas', consider the following statements:
1. Coalbed methane is the pure methane gas extracted from coal seams, while shale gas is a mixture of propane and butane only that can be extracted from fine-grained sedimentary rocks.
2. In India, abundant coalbed methane sources exist, but so far no shale gas sources have been found.
Which of the statements given above is/are correct?
Show answer
Answer: D. Neither 1 nor 2
Verdict
The answer is neither 1 nor 2. Both statements misdescribe the composition of shale gas and India's shale gas position.
Analysis
Statement 1 is INCORRECT. Coalbed methane is indeed predominantly methane from coal seams, but shale gas is not a mixture of propane and butane only. Shale gas is itself largely methane with propane and other hydrocarbons present, so the definition given is wrong on its main constituent. Statement 2 is INCORRECT. Shale gas bearing formations have been identified in India, and the Cambay basin in Gujarat was reported as a shale gas prospect, so the claim that no sources have been found does not hold.
Source
Indian Express report on the Cambay project and India's place on the global shale gas map.
How to crack it
Statement 1 carries the word only, which converts a loose description into an absolute claim, and one counter example destroys it. Methane in shale gas is that counter example. Statement 2 carries so far no sources have been found, which is a negative existence claim, and a single reported discovery destroys it too. When both statements in a two statement question contain a restrictive word, check whether neither 1 nor 2 is the intended landing point before anything else.
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