Dunedin to Catlins to Bluff

The Moeraki Boulders are the most perfect example of their kind found anywhere in the world. They consist of mud, fine silt and clay, cemented by calcite. The rock is riddled with large cracks that radiate outward from a hollow core lined with calcite crystals. They were formed in ancient sea floor sediments by a process similar to the formation of oyster pearls, where layers of material cover a central core. For the oyster, this core is an irritating grain of sand. For the boulders, it was a fossil shell, bone fragment, or piece of wood. If you visit this area make sure you come near low tide to get the best view of the boulders. Select the photo below to see more of this area.