The Moeraki Boulders are a range of boulders stretching from Moeraki to Hampden. These boulders are located on Koekohe Beach, North Otago. Created by giants, according to the prevailing local legend, these boulders are not only one of the most fascinating geological phenomenons in New Zealand, but also on Earth.
Set up on the flat surface of Koekohe Beach, they are around 1-2 metres in diameter and weigh many tonnes. There are around 50 of them and what’s brilliant about them is their geometrical perfection: they are perfectly round. These boulders are said to have been a result of concretion which is the precipitation of calcite in mudstone over millions of years and are a protected reserve on State Highway 1.
However, the future for these boulders does not seem too fortunate. Due to erosion, they are gradually falling open and coming loose on the shore of the beaches. Nevertheless, it is always good to capture this natural site when driving through the Otago Coast
These boulders date back 60 million years ago when there were sediments settling on the surface of the sea that included small particles of shells and plants. Slowly, calcite started to form, very similar to pearl formation. This caused the spherical nodules that had hard outer layers while the inner layers dehydrated, leading to cracks that spread to the outer rims of the boulders.
The gradual erosion and upliftment of the landmass in New Zealand led to the boulders emerging onto the surface of the sea. The entire process took over 4-6 million years. Today, the Moeraki boulders are considered one of the most precious natural phenomena in the world.