The Ancient Moeraki Boulders Moeraki New Zealand
These ancient boulders, the cores of which consist of bone, shell or plant fragments, were formed beneath the sea by calcium carbonate (calcite) slowly depositing around mud stone, c 60 million years ago.
© Sally Hill
Large cracked boulder at the edge of the cliffs. The boulders have been exposed along the shoreline by the erosion of the mudstone cliffs behind.