Monday, September 9, 2013

Visit to Moeraki Boulders

Even though Sarah and I have been in Dunedin for over a year, we haven't really started getting out of town until the last couple of months. We have no car (a refreshing experience for an American), and it hasn't been until recently that we've been lucky enough to be invited out of town with various friends, such as our department scientific illustrator Luke, and Zoology Postdoc Nic Rawlence and wife Maria Zammit (an Australian marine reptile paleontologist). Nic and Maria invited Sarah and I to go up the coast to Moeraki Boulders - I've driven by it about a dozen times with Ewan, and every time Ewan has said something like "We really ought to stop by there sometime - but not today!". We also visited Katiki Point, and those photos will be on the next blog post. The boulders are Paleocene in age, and the largest ones took about 4 million years of diagenesis to form. These photos are mostly going to be pretty, scenic photos and not really accompanied by much geologic information. However, the Wikipedia page has some great information.

The Moeraki Boulders are a series of enormous spherical septarian concretions with numerous radiating veins. The outer zone is well indurated, but when they crack open the middle is easily eroded. This boulder had lost the middle, and had a tidepool inside about 1 m above the beach.

Maria and Nic enjoying a snack at the boulders.

Complete and damaged concretions.

Sarah standing on a concretion.

Small pool between some concretions. The concretions on the right show the 
surface cracks from the veins.

Sand ripples and boulders.

The view north from Moeraki boulders with the Kakanui coastline off in the distance.

Nic Rawlence hanging out on a concretion.

Sarah sitting on one of the boulders - remember, she's short so it's not really that enormous.

Another pretty photo.

This one shows up in a lot of professional photos; this photo, I'll admit, is not very professional.

My wife, the concretion troll.

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