Pillow basalt

Pillow basalt is a type of rock that is formed when lava cools down very quickly in water. It's just like when you have hot water and you put ice cubes in it, the ice cubes cool down the water fast. When the lava comes out of a volcano and touches water, it cools down so quickly that it forms into a bunch of little pillow shapes.

These pillow shapes are made up of a special kind of rock called basalt. Basalt is really hard and strong, kind of like the bricks that a house is made of. The pillows of basalt that form are usually black or dark gray in color.

Pillow basalt is really important because it tells us about the history of our planet. We can look at these rocks and tell that there was a time when there was a lot of volcanic activity underwater. This means that the Earth's crust was moving and shifting a lot, creating new land and sea beds.

Scientists study pillow basalt to learn more about the Earth's past and how it has changed over millions of years. It's amazing to think that these pillow-shaped rocks can tell us so much about our planet!