Sedimentary rock types are formed when rock material is set loose as the result of erosion and transported into the bottoms of bodies of water. Over the course of millennia, these materials are compressed into dense layers. In time, these layers form new types of rock.

Sedimentary rock types can be identified by the presence of distinctive layers and different materials. Sometimes, even the patterns caused by ancient waves can be seen in sedimentary rocks.

Sedimentary rock types include sandstone and claystone, the names of which suggest from what kinds of material the types of rocks have formed.

Limestone is formed when the lime-rich shells of dead clams and gastropods are layered and condensed into stone. Magnificent limestone banks can be seen on the shores of the islands of Gotland and Öland.

There are very few types of sedimentary rock in Finland. Sandstone can be found in the Satakunta region, claystone can be found near Oulu and limestone can be found in Parainen.