Here are some examples of impermeable rocks:
* Clay: Clay has very small particles packed tightly together, leaving almost no space for water to flow through.
* Shale: Shale is a fine-grained sedimentary rock that forms from compacted clay and silt. It's also very dense and impermeable.
* Granite: Granite is a hard, igneous rock that is often very dense. While it may have small cracks, they are usually not large enough to allow significant water flow.
* Basalt: Basalt is another igneous rock, often found in volcanic areas. It is also dense and usually impermeable.
Important Note: Even impermeable rocks can have some water flow, especially if they have cracks, fractures, or other openings. The amount of water flow will depend on the size and interconnectedness of these openings.