Introduction | Energy | Water | Atmosphere | Ocean | Carbon | Nitrogen | Rock

The Rock Cycle

Over many thousands of years, energy from the Sun moves the wind and water at the Earth’s surface with enough force to break rocks apart into sand and other types of sediment. When sediment is buried and cemented together, it becomes a sedimentary rock such as sandstone or shale.

If rocks are buried very deeply, they are in an environment that is very hot and has high pressure. The crystals and texture of the rocks change as they turn into metamorphic rocks like marble or slate. If, deep underground, rocks are put under too much pressure and temperatures that are too hot, they will melt, forming molten rock called magma. Sometimes magma cools and forms igneous rock deep underground. Other times magma flows to the Earth’s surface and erupts from a volcano.

Rocks can affect the atmosphere! Erupting volcanoes send tiny particles of ash and gases into the atmosphere. Tiny particles of ash help make raindrops in the atmosphere as water condenses around them. The gases released from volcanoes can become sulfuric acid droplets that screen out sunlight. Large volcanic eruptions can even reduce Earth’s temperature for months or several years.