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Moeraki Boulders
Along Koekohe Beach, between Moeraki and Hampden, there are a series of spherical boulders. Some of these are the size of pebbles, while others are three metres in diameter. Kelly and I went on a photographic expedition to capture these geological oddities as part of our Oamaru trip. As I climbed on and around these rocky giants, a host of childlike questions ran through my mind: Are they dinosaur eggs? Are they the fossilised dropping of a Tyrannosaurus Rex? Why do the innards look like gobstoppers?

Deep in the history of Te Rununga Nga Tahu there is a story of the wreck of Ara Te Uru. The Māori people believe that this giant canoe foundered and the hull became the reef off Shag Point. The boulders formed when the food baskets and water gourds from the wreck washed up on the beach.

According to scientists the boulders are ‘septarian concretions’, and they were definitely not the flotsam of a wrecked canoe, or shat out by dinosaurs. They were formed on the bottom of the seabed and encased in the mudstone some 60 million years ago. The chemical balance around small deposits of organic material transformed the mudstone as the earth’s tectonic plates shifted. To me, with my non-scientific mind, it seems similar to how a grain of sand becomes a pearl in an oyster.

Today, millions of years later, with the aid of the tectonic plates and their uplifting action, the boulders are encased in the brown cliffs that flank Koekohe Beach. Thanks to the wave action of the Pacific Ocean, and the wild weather that assaults the coastline the cliffs are slowly eroding and the boulders are being ‘hatched’ out onto the beach. Similar boulders can be found at the Hokiangia Harbour, in the North Island of New Zealand.

It takes about an hour to drive to Moeraki from Dunedin, and there is ample parking space, a café and toilets at the main car park. It pays to check the tides before going, for two hours either side of the high tide the beach is basically inaccessible and the boulders covered by the waves. Also, dress warmly as we found the wind can be biting.

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Kelly and the boulders.
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Spllit Boulder