Bedrock is consolidated rock near or at the surface of the Earth. Soil and other loose strata, known as surficial deposits, often cover the bedrock. The bedrock geology map of Iceland classifies the bedrock on the basis of the rock type and age. A distinction is made between volcanic and plutonic rock, and between silicic rocks (e.g., rhyolite and dacite) and basaltic and intermediate rocks (e.g., basalt and tholeiite).