Fourth Grade
Worksheets
Landforms Under the Ground
Caves are hollow spaces in rock. Some caves are under the ground. They are formed when water flows through certain kinds of rock and dissolves it. Water seeps through pores in the rock. It soaks into cracks between rocks. Carbon dioxide dissolved in the water turns it into a weak acid. The acid slowly dissolves rock.
Some caves are small, but some are huge! Large caves may have a series of rooms. Each room may be bigger than a football field. Sometimes water fills a cave or a part of it. When this happens, underground lakes are formed.
Over time, water can create huge cave systems. These are most often found in limestone rock. Limestone caves are the largest and deepest caves in the world. There are more limestone caves than any other type of cave. They are intriguing to explore. They often have long, twisting tunnels. They have interesting formations inside.
