Fieldtrips in the Arctic

Of the time I have spent working as a PhD student so far (2 weeks), at least half of that time has been spent on field trips, and I have, in fact, only spent 1 day so far in my office. This feels somewhat like I've been thrown in the deep end, but it has been nice to spend time outside, getting used to glacial topography, and enjoying what I have been told is really nice weather for this part of the world (mostly like a nice sunny, but chilly winter's day in Cape Town). I've even seen people tanning. I think for me to consider 18˚C to be tanning weather I'm going to have to experience an arctic winter first. Anyway, the fieldtrips have also given me the opportunity to have some typical Norwegian experiences such as eating a waffle and brunost on a ferry (because apparently one cannot ride a ferry without having a waffle), and seeing reindeer.

My first field experience was for the masters tectonic course last week, looking at brittle and ductile deformation in archean TTG's and supracrustal metasedimentary and metavolcanic rocks at Torsnes. I saw some awesome folds, and amazing euhedral garnets the size of golf balls (unfortunately my camera died, so I don't have any photos of the outcrop, but I managed to hack a sample out of the rock, so a picture of a slightly-less-than-golf-ball size garnet is below.) Overall this was a nice geo-tourism trip for me and it got me used to walking on extremely slippery rocks.

Top left: Migmatitic deformed gneisses intruded by a planar felsic dyke which has subsequently been deformed by small shears. Top right: Ptygmatic folded felsic dyke. Bottom left: Buckle-folded pegmatite dyke. Bottom right: My desk-crop containing a massive euhedral garnet.

Perhaps a more challenging task was assisting with the 3-day first year structural geology field trip to Vannøya. Vannøya is an island northeast of Tromsø that requires the usage of several roads, a bridge, an undersea tunnel, and a ferry to get to (a +/- 4 hr round trip, which we did everyday). The trip was challenging not because the rocks are complex, or the content is difficult, or because it's a 60-student class, but because the undergraduates are taught entirely in Norwegian. Since I've been here only two weeks, my Norwegian skills are non-existent, and so I felt largely like a fish trying to climb a tree. Helpless and useless!

My first task was to translate the field guide, which is only in Norwegian. Google translate gave some amusing translations (sprø forkastinger (brittle faults) translates directly to "crazy faults"). It did, at least, give me some understanding of basic geological terminology in Norwegian, which I found came in handy when attempting to explain things to students. So my Norglish sounded something like this "Look at this kløv, see how it intersects the lagdeling so that it gives you a skjæringslinja. Have you measured the strøk og fall of anything yet?"

My second challenge has been actually understanding what is going on on the field trip. Since the Professor speaks Norwegian the entire time, it means I can't even understand the instructions the students are given, so I had to ask the students what they were supposed to be doing a lot of the time (and as those of you who do any teaching know very well, students usually don't know what they're supposed to be doing). Also, although all the students can speak english (and do so surprisingly well) they speak Norwegian amongst themselves, so I was almost always completely clueless as to what they were working on, or whether they actually needed help!

In terms of the geology, I found the whole exercise really became a test of my own observational ability, because I couldn't rely on a professor's explanations... which in the end was probably good for me. And I learned mostly that a confused-looking Norwegian student looks the same as a confused-looking South African student. Fantastic! Now I just need to learn to speak Norwegian. Hmmm.

First years on rocks

So now a little about the rocks at Vannøya; these rocks are the most pristine 2.4-2.2 billion year old rocks I've ever seen. They are low metamorphic grade (greenschist facies), folded and faulted, metasedimentary rocks (also intruded by some diorite), and the ripples and cross bedding are so well preserved that they could be in rocks only a couple of million years old. Perfect 2.4 billion year old ripples. Now that's rare! This is perhaps the one and only time I have, and will, get excited about sedimentary structures. The deformation in the rocks manifests as a series of several 100-metre scale folds with some smaller parasitic folds on their limbs, and a number of (mostly) strike slip faults. It's a pretty fantastic area for teaching because the students get the opportunity to see an unconformity, intrusive contacts, folded contacts, sedimentary structures, folds, faults, and perfect examples of bedding-cleavage relationships. Now let's hope that they actually saw all those things!

Top left: Intrusive diorite-sandstone contact defined by a layer of breccia. Top right: Slightly deformed pebble bed along the unconformity between the supracrustal rocks and older TTG's. Bottom left: Fold hinge! Bottom right: More folds.

Really old ripples (left) and cross bedding (right). 

And just because I cannot bring myself to end a post with sedimentary structures, here's a fault:

Thrust fault with mudstone footwall and sandstone hangingwall. Note the smaller faults in the hangingwall sandstone. 

On a side note: I caved and bought a tube of cheese today... it's pepperoni flavoured... the jury's still out on that one.