I apologize, but I don't have access to specific exam questions like the 49th question of IIT JAM Geology 2019. However, I can provide you with some general information and guidance on how to approach such questions in the geology exam.

1. Understand the Question:
Read the question carefully and understand what it is asking for. Identify the key concepts and terms mentioned in the question.

2. Break it Down:
Break down the question into smaller parts or sub-questions. This will help you analyze the question effectively and answer each part separately if needed.

3. Recall Relevant Concepts:
Recall the relevant concepts, theories, and principles related to the question. Think about the topics covered in your geology course that are relevant to the question.

4. Gather Information:
If needed, gather information from your geology textbooks, lecture notes, or any other reliable sources. Ensure that the information you gather is accurate and directly addresses the question.

5. Analyze and Solve:
Analyze the question and apply the relevant concepts to solve it. Use logical reasoning and critical thinking skills to come up with the correct solution.

6. Present your Answer:
Present your answer in a clear and concise manner. Use appropriate scientific terminology and provide any necessary explanations or calculations. Make sure to organize your answer in a structured manner.

Remember to manage your time effectively during the exam and allocate sufficient time for each question. It is also crucial to practice solving previous exam papers and sample questions to familiarize yourself with the exam format and types of questions that might be asked.

Additionally, it is important to consult your geology textbooks, notes, and other study materials for detailed information on specific topics.