Perfectly Spherical Boulders or Moeraki Boulders are found on Koekohe Beach, on the south island of New Zealand. These formations were created by hardening sea sediments that have been exposed through erosion. The boulders measure up to 3 metres in diameter, and were formed around 60 million years ago. Studies show their composition as magnesium and iron along with the stable isotopes of oxygen and carbon. Rocks measuring 2 metres in diameter ‘grew’ over a five million year period, when up to 50 metres of marine mud settled on top of them. The relentless pounding of waves has gradually eroded the softer stone and uncovered the spherical stones.
Spherical Boulders
