Kōrero: Rock, limestone and clay

This thin section of limestone from Raglan, South Auckland, shows the tiny sea creatures (in this case foraminifera) that make up the rock. Made of calcium carbonate, billions of skeletons and shells of ancient sea creatures have cemented together to form the rock. This process is continuous – off the shallow seas of New Zealand the limestone of the future is slowly forming as marine organisms die and sink to the sea floor.