For our next New Zealand Adventure we headed further south to the Moeraki Boulders, just outside of a small town of Timaru along the Pacific coast. The Moeraki Boulders are really neat. Almost perfect spherical rocks just plopped on the beach. According to my mom, they look like “petrified dinosaur poops.”
The Moeraki Boulders are unusually large and spherical boulders lying along a stretch of Koekohe Beach on the wave cut Otago coast of New Zealand between Moeraki and Hampden. They occur scattered either as isolated or clusters of boulders within a stretch of beach where they have been protected in a scientific reserve. The erosion by wave action of mudstone, comprising local bedrock and landslides, frequently exposes embedded isolated boulders. These boulders are grey-colored septarian concretions, which have been exhumed from the mudstone enclosing them and concentrated on the beach by coastal erosion. The most striking aspect of the boulders is their unusually large size and spherical shape, with a distinct bimodal size distribution. Approximately one-third of the boulders range in size from about 0.5 to 1.0 metres (1.6 to 3.3 ft) in diameter, the other two-thirds from 1.5 to 2.2 metres (5 to 7.3 ft), mostly spherical or almost spherical. A small proportion of them are not spherical; being slightly elongated parallel to the bedding of the mudstone that once enclosed them.
Enjoy the photos!