29 Apr 2013

Endless Basalt Columns in Iceland - a Geologist's Dream

When you visit Iceland, one of the first landmarks you're likely to visit is the wonderful Hallgrímskirkja (Hallgrims Church), that sits atop a small hill in the centre of Reykjavik. Architecturally it is magnificent, and when you travel around the volcanic countryside of Iceland you begin to understand where the inspiration for its design came from. There are basalt columns everywhere!

Although I studied geography up to 'A' level at school, I don't remember learning about basalt columns. I learnt about ox-bow lakes, folds in the earth's crust, the different shapes of volcanoes and so on, but basalt columns have either slipped from my memory, or were slipped from the curriculum. I've seen them in a number of different locations around the world over the years - Montagne D'Ambre National Park in Madagascar, Yellowstone National Park in the US, Chirpoy Island in Russia's Kuril Islands and even some up on the Isle of Skye and in Edinburgh, but I've never seen quite so many (or quite such impressive examples) as in Iceland - from Vestmannaeyar and Vík, to Stykkisholmur and Svartifoss, Arnastapi to Kirkjugólf, Dverghamrar and many many more!

Simply put, basalt columns are formed during rapid cooling of lava flow following a volcanic eruption. Fractures form during the cooling, and an extensive fracture network may develop and result in the formation of columns, which are usually hexagonal. They may be vertical or horizontal in orientation, although the most impressive ones, in my opinion, are the vertical, hanging ones.

Below is a small selection of the basalt columns that I saw on my visit to Iceland this year. Notable locations around the world can be seen on this useful Wikipedia page.

The first one I came across on this recent trip was at the black sandy volcanic beach of Reynisfjara, near Vík, along the south coast of Iceland. The beach had been gouged away since my trip a year earlier, revealing more of the base of the fascinating columns. I got there just in time to see the soft golden light in the half hour before sunset cast an orange glow on the columns.

A couple of days later I was further east (having passed a couple of columnar sites, but having decided to visit on my return in hopefully better weather), and I hiked up to Svartifoss, a waterfall that drops between vertical columns in a very striking setting in the Skaftafell National Park. I'd visited the previous year and it was one of my favourite spots - a half hour uphill hike was well worth the reward at the end. This year there was lots of ice around, so it looked completely different. The flow from the waterfall was tiny, and large icicles hung from some of the columns, crashing rather scarily down to the ground every once in a while. The columns themselves were dry, where last year they had been moist from the spray from the voluminous falls. Some of the columns were rusty from the oxidation of iron-rich mineral deposits.

After a few days in the south-east I tore myself away from the iceberg-littered Jökulsárlón beach - my favourite spot - and headed back along the ring-road. The first stop was Dverghamrar, a couple of columnar outcrops near a pretty waterfall (Foss á Sidú). The name means "Dwarf Cliff" but I couldn't really see the dwarflike resemblance. The weather was a little overcast, but the sun attempted to peek out as I was there.

Back in the car and on to Kirkjugólf, which means "church floor" in Icelandic. It was never the site of a church, but could easily have been mistaken for this, with smooth and pretty regular hexagonal stones - the top of columns that lie underground. Again, the sun briefly came out for me while I was there. My decision to postpone my visit to these sites on my return journey had been a wise one!

I stopped at Vík again, this time visiting the beach at Dyrhólaey, which had also suffered some beach erosion since my previous visit. Only the tops of the basalt columns were visible at the beach, jutting out of the cliff against the shore. The weather by now was pretty dismal.

I had one more trip to the beach at nearby Reynisfjara, hoping that the weather would miraculously improve for sunset, but no such luck. The winds were strong and cold, as usual, but I got a last chance to marvel at these wonders of nature that have inspired so much of the architecture and sculptures in Iceland.

I'm sure I'll find even more next year...

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