Wednesday, March 19, 2008

March 8, 2008 - Moeraki

After 3 days of enjoying the cosmopolitan pleasures of Dunedin, we pointed our wagon north and headed out of town. We didn't have to cover much distance today, so we took the opportunity to explore anything (and everything) along the way that struck our fancy. We spent a while wandering around a deserted old farmstead. A bit further up the road we took a short hike in the woods, where a little fantail followed us around, eating the insects disturbed by our footsteps. Around midafternoon we stumbled across the rest of the tourists at the Moeraki boulders.
These strangely spherical boulders are formed much like a pearl. Unlike typical boulders, which emerge from bedrock, they are created through the process of concretion. Nobody really knows what forms the nucleus of the these boulders, but theories include fossilized bits of shell and bone fragments. Over time, calcite layers build up around the nucleus, creating the round rocks. The ones on the beach at Moeraki aren't the only ones in the world, but they are particularly spherical, and large (some have a diameter of more than 2 meters across). Scientists believe that they took about 4 million years to form, one layer of calcite at a time. As the cliff above the beach erodes, the boulders emerge, and roll down to the shoreline.

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