Moeraki Boulders
Exploring a fascinating geological phenomenon located on Koekohe Beach, near Moeraki on the east coast of the South Island
NEW ZEALAND
The Moeraki Boulders are a fascinating geological phenomenon located on Koekohe Beach, near Moeraki on the east coast of the South Island of New Zealand. These large, spherical boulders, some reaching up to several meters in diameter, are scattered along the beach and emerge from the eroding cliffs.
The boulders are spherical rocks-concretions that reach over 1 m across. They started to form about 55 million years ago, when mud, pebbless, and shells were deposited on a quiet sea floor, and gradually buried. In places, lime was deposited slowly and evenly around a shell or pebble, to form a hard, cemented, spherical concretion.
While still buried, some concretions split, and became infilled by walls of yellow crystals of lime. As the region was uplifted in recent geological times, the sea eroded nearby cliffs of mudstone, to free the boulders from their encasing softer rock.
The boulders in the water have been weathered by the waves but new ones are constantly being unearthed by high tides and the large waves and storms washing away the sand.
The rocks were such a unique feature on the landscape as we walked around the beach. Arriving near low tide makes it easier to reach all the the boulders and see them up close.
This is truly a continually evolving landscape and one not to miss on your trip down the east coast of the South Island. Happy exploring!
