pyroxene

Rocks as grief therapy

Today’s song is Queen’s Under Pressure.

Five years ago, a light went out in my life.

I was heartbroken and lost. There was a vast expanse of future ahead and I had no idea what it would look like. Friends told me to keep moving forward but I could only look back and I knew I had to find something that would take me away from it.

So I packed up my car and started to drive. I had no idea where I was headed except that it had to be far, far away from the suffocating present. If I could drive off into the future maybe I would get there sooner, shortcut the grief process, and stave off the free-fall plunge to excruciating pain that I knew lay ahead.

I had music blaring, boy-racer style, although my stereo system was way too under-bassed. Unashamedly, I sang my heart out in between bouts of ab-wracking sobs and cascades of tears that flowed down my cheeks in biblical proportions. After 8 hours, I was gently welcomed into Nelson by soft apricot hues in the sky. They were gradually deepening, behind the hills, as a curtain of indigo began to descend on the already dark day.

Next morning, I rose to a crystal clear sky and a frost. Those are the mornings I love best – always the promise of warmth, as the day wears on, and the light turns even ordinary things into something magical. Tramping in the autumn crispness is one of life’s joys so it seemed like a natural solution for an escape. Maybe a trip up Dun Mountain, behind the camping ground where I spent the night, would offer some respite. I had learned a little about it, during a cursory foray into ultramafic rock types, in my Earth Science class.

dun mountain track sign-1000650

Ultramafic, I learned, was a very dark-coloured rock containing a high proportion of mafic minerals. These are magnesium and iron. Mafic comes from magnesium and the chemical symbol for iron, Fe. These rocks originate in the mantle – that layer of the Earth which lies beneath the crust:

Earth's layers showing peridotite region. Credit: Janis Russell

Earth’s layers showing peridotite region. Credit: Janis Russell

The track up to Dun Mountain was beautifully graded and I met several mountain bikers on the way up. I planned to take my time and stay at the aptly named Rocks Hut and finish off the extra the next morning. At that time of the year there was hardly anyone about once I veered off the graded path.

Higher up, the immediate landscape of tussock and rock takes on a strangely golden hue and contrasts with the dark, bush-covered hills in the distance.

mountains view2-

The rocks are knobbly and rough and are part of the Dun Mountain Ophiolite Belt. They are composed of Dunite, a type of peridotite named after this place, which consists mainly of a beautiful, green mineral called olivine (after the colour olive) together with a little of another mineral, pyroxene.

Normally these rocks don’t appear at the surface because olivine usually reacts with water in the upper crust and is altered to serpentinite. However, a section of the oceanic crust and underlying mantle was uplifted and exposed above sea level (an ophiolite). Dunites are usually surrounded by bands of serpentinite. During the alteration process, copper atoms in the structure of pyroxene are forced out. Metals in the rock like chrome and nickel prevent plants from growing, or at least severely limit them.

Serpentinite

Serpentinite

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Coppermine Saddle en route to Dun Mountain

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Ultramafic rock isn’t conducive to plant life but there are exceptions.

I sat down for an hour or so just looking at the view, soaking up the sunshine and inspecting the rocky surroundings. These rocks are such a tactile experience. Here I was, reaching through the time warp, touching a rock that was about 280 million years old. I imagined the hundreds of kilometres I had driven to get here and if I travelled the same distance straight down into the Earth I would be in the peridotite zone. The temperatures are extremely high – enough to melt the rocks, but they don’t. The pressure of the overlying rock prevents it from doing so. It remains solid but continues to flow. I guess that my friends were right. No matter what the conditions we can keep moving even if it’s just baby steps.

Then the time came to leave. I walked out and during the descent followed the transition down back into the lushness of the bush. A small waterfall stopped me in my tracks. A strange yet familiar sensation spread across my face as the corners of my mouth pushed upwards of their own accord. A cascading waterfall is cleansing and mine would be too. The escape was brief and not entirely complete but those couple of days, alone in the hills, allowed me time to sow the seeds for a different future – a future which included rocks.

waterfall2-1000777

 

Header photo credit: Rob Lavinsky, iRocks.com – CC-BY-SA-3.0