Koutu Boulders - Hokianga
A couple of the Koutu Boulders in the Hokianga Harbour, New Zealand. It was late in the afternoon and it was getting quite dark already.
I think I must have been at the wrong end of the beach as I only saw a handful of them.
The boulders are excellent examples of concretions : hardened nodules that form within sedimentary rocks. The word concretion comes from Latin and means “grown together”. They are composed of the same material as the surrounding rock and they form when a cementing mineral binds grains of sediment into a cohesive mass. It has been estimated that the largest of the boulders may have taken 5 million years to grow.
There are other examples of concretions around New Zealand, the most publicized being the Moeraki boulders south of Oamaru. The Concretions in the Hokianga are found on both sides of the Harbour, and are numerous beneath the surface of the surrounding land.
Koutu Boulders - Hokianga
A couple of the Koutu Boulders in the Hokianga Harbour, New Zealand. It was late in the afternoon and it was getting quite dark already.
I think I must have been at the wrong end of the beach as I only saw a handful of them.
The boulders are excellent examples of concretions : hardened nodules that form within sedimentary rocks. The word concretion comes from Latin and means “grown together”. They are composed of the same material as the surrounding rock and they form when a cementing mineral binds grains of sediment into a cohesive mass. It has been estimated that the largest of the boulders may have taken 5 million years to grow.
There are other examples of concretions around New Zealand, the most publicized being the Moeraki boulders south of Oamaru. The Concretions in the Hokianga are found on both sides of the Harbour, and are numerous beneath the surface of the surrounding land.