1. The Science of Caves

2. About Caves
Caves are natural openings within the earth that usually extend deep beyond the reach of light. They are found in many types of rock, but are most common in limestone and gypsum. These caves were formed by water under the surface of the earth.
A second type of cave is the lava cave, formed as liquid lava flows.
A third type of cave is the sea cave. Sea caves were formed along cliffs and rocky seashores.
The study of caves is known as speleology, and those who explore caves are called speleologists.

3. How are caves formed?
Caves are usually made when water runs over soft rock, such as limestone.
The acid in the water slowly eats away the limestone, making a hole. The hole gets larger and larger. If the water finds a new path, the cave is left dry.
Caves can also be created when hot lava melts rocks, forming holes. Occasionally, the ceiling of a cave collapses, leaving a huge room or cavern.
Tidal waters along a coast can also carve out caves.

4. Facts about caves
Dripping water contains lime, or calcium bicarbonate. Over hundreds of years, the lime builds up and hardens, becoming stalactites.
Sometimes stalagmites grow up from the floor of a cave. In all cases, these sculptures are caused by mineral deposits that have hardened.
Caves provide shelter for many animals, such as bats, insects and hibernating mammals.
A cave is also called a cavern.
Exploring caves is called caving, potholing, or spelunking.

5. Let’s experiment Steps:
You will need:
Clay
Sugar cubes
Newspaper/Clay mats
This experiment helps to explain how caves are formed.
Steps:
The clay represent sandstone, a hard rock, and the sugar, limestone.
Working on a newspaper-covered surface, mould the clay around the sugar cubes, being careful to leave at least part of a sugar cube exposed.
The shape of your sugar cubes, will be the shape of your cave.
When you have finished constructing the cave, leave it to dry for several days. Then soak the structures in water.
The sugar will dissolve, leaving the hollowed out spaces.