Question

Which of the following materials is an example for aquitard?

• A. sand and poorly fractured metamorphic rock
• B. clay and highly fractured metamorphic rocks
• C. till and highly fractured metamorphic rocks
• D. poorly fractured metamorphic rock and clay

Hint:

Aquitards hinder water movement — think dense or poorly fractured materials like clay and metamorphic rock.

Answer 1

The Correct Option is D

To understand which material is an example of an aquitard, let's break it down step by step:

1. What is an Aquitard?
An aquitard is a layer of rock or soil that allows water to pass through, but very slowly. It's like a sponge that's hard to squeeze - water moves through it, but not easily.

2. Key Features of Aquitards:

• They have tiny spaces (pores) between particles
• Water moves through them very slowly (low permeability)
• They often act as barriers between aquifers (water-bearing layers)

3. Analyzing Each Option:

Option	Why It's Good or Bad
Sand and poorly fractured metamorphic rock	Sand lets water through too easily
Clay and highly fractured metamorphic rocks	Fractures let water move fast
Till and highly fractured metamorphic rocks	Till is mixed, fractures are bad
Poorly fractured metamorphic rock and clay	Perfect! Clay + unfractured rock both slow water

4. Why Clay + Poorly Fractured Rock is Best:

• Clay has tiny particles that block water
• Unfractured rock has no cracks for water to flow through
• Together they make the best "slow water" layer

5. Real World Example:
Imagine a peanut butter sandwich:

• Bread = aquifer (lets water through)
• Peanut butter = aquitard (sticky and slow)

The clay and unfractured rock are like the peanut butter!

Final Answer:
The best example of an aquitard is poorly fractured metamorphic rock and clay.