* "Impermeable" means: A material that does not allow fluids (like water) to pass through it.
* "Bedrock" means: The solid rock that lies beneath soil, sediment, and other unconsolidated material.
What is important to consider:
* Type of Rock: Different types of rock have different permeabilities.
* Permeable Rocks: Sandstone, limestone, fractured granite. These allow water to pass through them.
* Impermeable Rocks: Shale, claystone, unfractured granite. These resist water flow.
* Fracturing and Weathering: Even impermeable rocks can become permeable if they are fractured or weathered. This creates pathways for water to move through.
* Context: The term "impermeable bedrock" is often used in the context of groundwater. If the bedrock is impermeable, it can act as a barrier, preventing groundwater from flowing deeper into the Earth.
To get a more specific answer, you need to consider:
1. Location: Where are you interested in?
2. Purpose: What are you trying to understand?
* Groundwater movement?
* Construction?
* Environmental impact?
Example:
* "The impermeable bedrock beneath the city prevents groundwater contamination from reaching the aquifer." This implies that the bedrock is acting as a barrier to water flow, protecting the aquifer.
In short, "impermeable bedrock" refers to any bedrock that significantly restricts the flow of water. The specific rock type, its fracturing, and the context of its location determine how impermeable it truly is.
