Aquifuge

An aquifuge is a geological formation that does not contain any amount of groundwater. It acts as an impermeable barrier, preventing the movement of water through it. Unlike aquitards, aquifers, and aquicludes, aquifuges do not store or transmit water.

Explanation:

Aquitard:
- An aquitard is a geological formation that has a low permeability, meaning it restricts the movement of groundwater but does contain some amount of it.
- Aquitards act as barriers to the flow of groundwater and can store water, but they do not transmit it easily.
- Examples of aquitards include clay, silt, and shale layers.

Aquifer:
- An aquifer is a geological formation that can store and transmit water.
- It is composed of permeable rocks or sediments that allow the movement of groundwater through them.
- Aquifers are a vital source of water for wells and springs.
- Examples of aquifers include sand, gravel, and limestone layers.

Aquiclude:
- An aquiclude is a geological formation that can store water but does not transmit it.
- It is composed of impermeable rocks or sediments that prevent the movement of groundwater.
- Aquicludes act as barriers to the flow of water and can store water within their layers.
- Examples of aquicludes include clay and shale layers.

Aquifuge:
- An aquifuge is a geological formation that does not contain any amount of groundwater.
- It is composed of impermeable rocks or sediments that completely prevent the movement of water.
- Aquifuges act as impermeable barriers and do not store or transmit water.
- Examples of aquifuges include solid rock formations such as granite or unfractured basalt.

Conclusion:
The correct answer is option D, Aquifuge. Aquifuges do not contain any amount of groundwater and act as impermeable barriers, preventing the movement of water.