Generally:
* Bedrock: In most places, the soil layer rests on a layer of solid rock called bedrock. This is the foundation of the Earth's crust.
* Regolith: Above the bedrock, there can be a layer of loose, broken rock called regolith. This is formed by the weathering and erosion of the bedrock.
* Groundwater: Below the soil and regolith, there is usually a layer of groundwater, which is water that saturates the spaces between rocks and soil.
Specific Locations:
* Coastal Areas: Below the soil, you might find sand, clay, or even rock formations like limestone or sandstone.
* Mountainous Regions: In mountainous areas, the bedrock is often exposed, with little to no soil.
* Deserts: Deserts can have layers of sand, gravel, or even clay below the soil.
* Swamps and Marshes: In swampy areas, you might find layers of peat or mud below the soil.
Important Note: The depth and composition of these layers can vary significantly depending on the location and geological history of the area.
