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Hyalocalstite rocks and the Gæsavatnaleið

Hyalocalstite rocks and the Gæsavatnaleið

The following day was to be our first rock sampling day in Iceland. We were looking to find specific types of rocks called hyaloclasites. These rocks were formed during submarine or subglacial eruptions. The rapid cooling of the erupting lavas in contact with cold water/ice produced volcanic glass fragments through a process called quenching. Within these glass fragments we hoped to find primary olivine crystals that would preserve geochemical information about the magmas and their sources.

The typical view from central Iceland, 2016

Paul Martin had pre-picked numerous volcanic targets across Iceland based on previously published data. The main target for that day was a volcanic center named Kistufell. Located just north of Vatnajökull, Iceland’s largest ice cap, Kistufell is not an easy place to get to. The F-road we had to take was one of the roughest and most notorious roads in Iceland: Gæsavatnaleið.

The road to Vatnajökull

From our lodging at Nyidalur we drove north on the F26 to get on the F910. The weather was perfect. Sunny and mildly warm with a slight cool breeze. The F910 would take us back south towards Kistufell, as well as other targets along the way. Our first one was a small and insignificant looking mound of rocks in the middle of nowhere called Bokki.

Basaltic mound (tumulus) at Bokki

There were still no hyaloclastite rocks at Bokki, but we did grab a couple of basalt fragments that were rich in olivines. Despite not being the target rock, this would end up being quite a good sample later on.

Further along the road we reached the second target of our day, Kambsfell. Here is where we found our first hyaloclastites. These rocks were basically breccias containing pillow basalt and volcanic glass fragments held together by a compacted brownish crystal matrix. Very easy to break off and sample with a hammer.

My first hyaloclastite rocks and a nicely shaped pillow basalt at the bottom

Following the road southeast, we reached a junction where we turned towards Gæsavatnaleið. To this day I’m uncertain if Gæsavatnaleið is just a section of the F910, or is the actual name of the entire road. It’s fairly hard to figure out these roads based on google maps and the limited information available online. For the purpose of consistency, I’ll just stick to calling Gæsavatnaleið the portion of the road that came after the aforementioned junction and ran along the northern edges of the ice field.

Gæsavatnaleið – as rough as they come

We had reached the northwestern edges of Vatnajökull and were now driving parallel to the grand glacier. At certain points it would have been easy to pull over and just run over to touch the ice, but we had to stay focused on our work.

Getting closer and closer to the Vatnajökull ice cap

Soon enough the vast flood plains of the ice field opened up before us. The road seemingly disappearing in a large canvas of wet sand and shallow water flowing down from the glacier. A continuous set of road pilons were the only thing keeping us from completely veering off course. Occasionally, we could see fresh tracks of vehicles that had previously left their mark in the sand.

Paul was driving slow and steady over the wet sands, but the car was showing signs of poor grip. There were several occasions where we feared we might get stuck in the sand. Unfortunately I have no images of the flood plains, but for anyone curious, there is this video I found on YouTube showcasing this section of the Gæsavatnaleið.

On the way to Kistufell, passing several fascinating volcanic edifices. Some might think we were in the heart of Mordor

After about 10 kilometers of flood plains came the basalt fields. We were back on solid rock at least, but it was the bumpiest “road” I’ve ever experienced. As opposed to other sections of the F910, the road here was rarely level and barely graded. At times it simply consisted of continuous rounded mounds of basaltic outcrops with the all too familiar road pilons telling you which way is less deadly to go. The whole SUV was rattling from side to side for the rest of the way. Suffice to say, our car did not have a good time.

Kistufell, a harsh wasteland

The last bit of road before reaching Kistufell was extremely rough. The belly of the car took more then one bump on the rocks while we were traversing the old lava flows. But everything seemed fine when we finally came to a stop.

I tried to take some photos of the various terrain we saw from the car, but the bumpy road did not help at all

In the vicinity we spotted a massive crater, Urðarháls, just northeast of the road. The road didn’t exactly lead to our mountain, but it got us close enough that we just had to hike a short half an hour south to reach it.

Remarkable features of the an old subaqueous fissure eruption

On our way we passed long, jagged stretches of rocks that were the results of old fissure eruptions along the rift. Being hyaloclastites in nature, we sampled these as well. As we passed the fissures and volcanic edifices nearby, the landscape opened up to reveal Kistufell. A towering, elongated mountain with patches of snow covering it’s steep inclines.

Mount Kistufell, at last

To reach Kistufell we had to cross an open field of old lava flows, sprinkled with ash and pumice. I kept remarking how the flow-direction features frozen in the basalts beneath our feet reminded me of that thin, wrinkly top crust of cooling mushroom soup. I was indeed craving mushroom soup at that point…

The “wrinkly” looking basaltic flows that reminded me of mushroom soup

After crossing that barren wasteland we reached the base of Kistufell. We climbed slightly up the steepening slope to get a fresh sample from the outcropping rocks.

Trouble on the horizon

The weather had stayed good thus far. However there were quite a few dark clouds gathering towards the east. With our work done, we considered having a late lunch break under the mountain as it was well in the afternoon.

The barren wastelands around Kistufell

As we stood there debating, we noticed an ominous haze growing on the horizon. A pale-brown veil began falling over the landscape in the east. We weren’t sure what it was, but quickly decided to best head back to the car.

We proceeded to cross the open wasteland once more. As the brown haze grew in size it became apparent that it was in fact an approaching dust storm. We covered up as well as we could and continued our hike. Within a matter of minutes the storm was upon us.

It was at this moment we knew that we were screwed

Fine-grained volcanic ash and pumice engulfed us in a windy torrent. Anything that wasn’t fully covered up like my ears, quickly filled up with dust. My sunglasses and buff were barely enough to keep the debris from my getting into my eyes, nose and mouth. I had to squint walking back the whole way as I felt the sand creeping in around my glasses. I could even taste the grains of dust in my mouth as we pushed trough the storm.

Trying to capture the dust storm… Good thing my camera survived

Finally, we reached the car and much needed relief from the harsh elements outside. Having never been in a desert myself, I couldn’t begin to imagine how awful one of these dust storms could truly be.

By the time that we finished our lunch it was passed 3 pm. The dust storm had passed and we were ready to head back to camp. The drive back should have taken us about one and a half hour. However, things didn’t exactly go smoothly.

We have a problem…

As soon as we started driving, something was off. We felt the car bouncing around way more than it should be. We weren’t sure if it was still just the awful road, or if there was a problem with the vehicle. After about 10 minutes of violently rattling around we decided to pull over and have a look at the tires. However, there were not flats and the pressure on all four tires looked to be fine.

On our way we passed one of Iceland’s largest shield volcanoes, Trölladyngja

I took the opportunity to answer natures call and when I was walking back towards the car I noticed something very strange. From afar, the back of the car was clearly tilting downwards. I told Paul and then it became even more clear that the chassis was barely above the back tires whereas there was significantly more space in the front. Could something have happened to the suspensions we wondered? But how?

We tried to look under the car, but due to the vehicle design and heavy dust cover we could barely see anything. At that point there was not much we could do anyway, so we decided to continue on slowly.

In the desolate brown-grey wastelands of central Iceland, Vatnajökull shined blindingly bright

The rocking became extremely violent as we drove over the worst parts of the F-road. It became more and more obvious to us that there was a serious problem with the suspensions.

In the middle of nowhere

Paul Martin was increasingly concerned about crossing the flood plains with our damaged car. With the stops we made and the slow driving, it was now passed 4 pm. As it was getting late in the day, the chances of any more traffic on the Gæsavatnaleið were dropping rapidly. This meant that our chance of potentially getting help in case we got stuck were quickly diminishing.

Ash fields, lava flows and volcanic ridges

We stopped the car on the last ridge before the flood plains. I remember us preparing a plan in case we had to ditch the car and walk. Luckily we spotted a shelter hut on our way to Kistufell, so we knew we could at least take shelter for the night. However, that was past the flood plains. Over 10 km away. It was the best we could come up with though.

We got out of the car and walked around to try to get reception on our phones. By some miracle my phone managed to scrape up one measly signal bar close to the hood of the car. Paul immediately called the car rental agency to explain our predicament.

I recall it was frustratingly funny to try to explain to the guy where we actually were: Central Iceland, north of Vatnajökull on the Gæsavatnaleið, east from the F910 junction and west of Mount Kistufell. The guy had no clue. Then I realized we had Garmin GPS devices on us. As I was telling Paul that we can give them coordinates, my phone lost reception and the call got cut off.

Man in the middle of nowhere

About 15 minutes and several attempts later, we managed to reestablish connection and give them our coordinates. The guy’s response was “So you’re in the middle of nowhere…”. Yes. Yes we were.

The resolution to our adventurous day

The guy told us that there was nothing they could do for us there. We had to bring the car back to Akureyri where they could have a look at it. Paul explained to him the potential hazard we were facing by crossing the flood plains and asked for advice. The guy didn’t know what to say so he took some time to consult with his colleagues. Another 15 minutes later he got back to us and suggested we attempt the crossing. Their thinking was that with the car’s weight bouncing around a lot more, it may actually keep us more buoyant when crossing the water and wet sand.

There was only one way to find out. In any case, we were to check back with them if we crossed safely or ran into any more trouble. Considering the poor signal coverage, it was unlikely they’d hear from us again if we did get stuck. Luckily, the flood planes proved to be a breeze to cross. Perhaps there was indeed something to their buoyancy idea.

All of in a day’s work for a geoscientist

It took us another two hours to slowly get back to camp. Poor Paul was completely exhausted by the end. We were both relieved and grinning proudly back in camp. We had gotten our first set of samples, endured the unforgiving dust storm and survived one of the worst roads of the Icelandic highlands, with a broken car no less.

Yet with all of this taking place within just the first day of field work, we knew there was much more to come. I was cautiously curious what this alien world would have in store for us in the coming days.