Chalk Formation

Chalk is a type of rock that is made up of tiny little sea creatures called coccolithophores. These little creatures have hard shells made out of something called calcium carbonate.

When these creatures die, their little shells sink to the bottom of the ocean and over time, with a lot of pressure, they turn into the chalk rock that we use to write on chalkboards.

So, chalk formation basically means that all of these little sea creatures, through a process that takes millions of years, end up forming a type of rock that we can use to write on things! Cool, right?