January 20, 2023: South from Oamaru enroute to Dunedin lie the bizarre Moeraki boulders, lying on the beach like petrified dinosaur eggs.
“Whoa, I think those must be Gozilla eggs!”
The almost perfectly spherical boulders are not fossilized eggs, of course. But they are just as fascinating, and often have hidden secrets to reveal.
Concretions
The stones are concretions, formed when dissolved calcite in groundwater precipitates concentrically around a particle, much like an oyster creates a pearl around a grain of sand. Often they form around organic material – a leaf, tooth, or small dead animal, so concretions do sometimes contain fossils. They can form rapidly (geologically speaking), taking shape in months to decades. As the softer earth around the concretion erodes, the hard calcite spheres are exposed.
The Moeraki Boulders
The Moeraki boulders lie on a beautiful remote beach area just off of State Highway 1 enroute to Dunedin. The government protected the area, and built hiking paths and a pleasant tourist shop. The hike makes a short and easy leg-stretch as you drive down the coast. I would however skip the over-priced restaurant.
Shag Point
Just beyond Moeraki is Shag Point. We didn’t see many shags (New Zealand cormorants). But fur seals abound here. Once hunted nearly to extinction, they are making a comeback and are a common sight lounging on the rocks of the south coast.
Allans Beach
We arrived in Dunedin early, so made a side trip to Allans Beach on the Otago Peninsula. There we found rare Hooker Sea Lions lounging on the sand. They look lazy, but these are top predators in the area, eating fish and penguins. Do not put yourself between them and the water; they are known to come violently awake. Believe it or not, they can move 3x as fast as a person on the beach over a short distance.
Next up on the road trip… Dunedin and Burns Night.