Macca 'Rocks'
Imagine if you will, a group of expeditioners out on a walk on a rare sunny day here on Macquarie Island. Despite the bright sun, everyone is rugged up against the cold biting wind, sporting heavy jackets and colourful beanies. They have formed a firing line of cameras aimed at a couple of wrestling elephant seals. The seals are grunting and burping as they rise up to bite and overpower each other. In the background massive waves crash on the black beach, sending sun kissed golden sea spray over a group of penguins. It is an absolute spectacle that encompasses the wonders of this beautiful and harsh island.
However, you notice one expeditioner facing the wrong way, kneeling in the mud and wet sand. They are missing the amazing scene behind them. Did they trip? Are they hurt? No. I have just found a cool rock. The island is made almost entirely of interesting geology, and I am like a kid in a candy store. Rock candy, of course.
While I am strictly an amateur, I am quickly learning about the different types of rock on the island. Each rock and formation tells a story and gives a glimpse of the history of the Macquarie fault zone.
Green, magnesium rich serpentine, snaking its way along a ridge, tells a story of rock forming before being pressure cooked into a new form.
The thick quartz veins dispersed so regularly and reliably that you could set your watch to them. These are where faults in the rock were flooded by super heated, silica rich water, which then solidified.
The round polished basalt stones, formed from cooling and solidified molten rock. When this molten rock erupts and cools underwater it is called pillow basalt and makes a great rock for a sleepy seal to rest their head.
The black volcanic glass offers us a window back in time where magma cooled so rapidly that crystals could not form.
With so much beauty around us it can be easy to forget we are living on an active fault line too. As I write this, we haven't had any tremors yet. But when one hits, we might need a stiff drink. Martinis perhaps? Shaken, not stirred.
On a geological time scale, we will only be on the island for the blink of an eye. But it's such a privilege to see and live on the very bones of the earth as they rise out of the ocean and provide habitat and shelter for such vast array of animals and plants.
Simon.
