The History of the Moeraki Boulders

Moeraki Boulders are just one of the many naturally occurring oddities that are found on Koekohe Beach and surrounding areas in New Zealand. Some have likened the appearance of these boulders to the bowling balls of giants, who have long since abandoned their game. In a way, they do look like bowling balls because some of them are nearly perfectly spherical. This sort of boulders occur naturally elsewhere, but the number of them in the area and the beauty of the surrounding New Zealand landscape seems to draw people to the Moeraki Boulders in particular.

Roughly 56 million years ago (during the Paleocene Epoch), small bits of wood, fossils and bones on the bottom of the ancient sea floor began to accumulate layers in what is now New Zealand. Over time, these small formations grew larger and larger in much the same way an oyster’s pearl grows in size. The large, round stones that resulted from this process are known as septarian concretions. They eventually became trapped in the stunning sheer cliffs that grace the coast of Kohekohe Beach between Moeraki and Hampden, New Zealand.

When erosion began to take its toll on the cliffs, the ancient Moeraki Boulders were freed. Today, they are scattered across the landscape like errant marbles. Some are not spherical, but are oval instead. These Moeraki Boulders look like dinosaur eggs, really big ones, at that. Some of them have cracked open and revealed their softer, eroded interior. Some of these are big enough for a man to sit in, giving the appearance that he has just been hatched from the ancient stone. The biggest of the Moeraki Boulders are close to nine feet in diameter and weigh several tons.

The surfaces of the Moeraki Boulders are cracked, causing them to look like turtle shells. The reason for this cracking is yet unknown to science. We do know that the interiors of the boulders are weaker than the exteriors, yet the exteriors are cracked. Some of the boulders are much smaller than others. The cracked surface makes them look like large turtles half-buried in the sand.

An 1848 drawing by W.B.D. Mantell shows the Koekohe Beach with more of the Moeraki Boulders than are currently there, so they are slowly vanishing. However, more are still trapped in the cliffs, as evidenced by those that are only half-exposed today. There is no telling how many of them are still waiting to be revealed.


De Hek, Danny, retrieved 10/28/10,

Facts about Moeraki Boulders, retrieved 10/28/10, moeraki-boulders-facts.php

Evans, RJ, The Mysterious Moeraki Boulders,