In this episode we hear from Bjørn Thomassen, Emeritus senior scientist at the Geological Survey of Denmark and Greenland, about what drew him to Greenland and kept him coming back for 42 summers, working as an economic geologist and mineral prospector.
In this episode we hear from Bjørn Thomassen, Emeritus senior scientist at the Geological Survey of Denmark and Greenland, about what drew him to Greenland and kept him coming back for 42 summers, working as an economic geologist and mineral prospector.
Transcript
04: Bjørn Thomassen – ‘Taken in’ – the beginnings that led to 42 summers exploring Greenland
Based on interviews held on September 30 – October 2, 2019 in Copenhagen, Denmark
Note: Polar Podcasts are designed to be heard. If you are able, please listen to the audio, which includes emotion and emphasis that's not evident in the transcript.
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Bjørn 0:02
So I really choose geology as my er profession not out of a special interest for geology but as a means to get to Greenland.
Julie 0:11
Welcome to Polar Podcasts, where you’ll hear stories from geologists who’ve spent their careers, their lives, exploring and studying the remarkable and remote geology of Greenland. Why did they become fascinated with Greenland? What were the problems and the discoveries that drove them? And what was it like working in these remote places, where few people venture, even now? I’m Julie Hollis.
In this episode we hear from Bjørn Thomassen, Emeritus senior scientist at the Geological Survey of Denmark and Greenland, about what drew him to Greenland and kept him coming back for 42 summers, working as an economic geologist and mineral prospector.
Bjørn 0:56
Yeah, my name is Bjørn Thomassen. I was born here in Copenhagen in nineteen hundred and forty two. And er I spent much of my adult life summers in Greenland doing er geological fieldwork and mineral exploration and at the same time spending the most of the year actually the winter time in Copenhagen doing office work. My interest in Greenland er built up. I mean, as a child I heard stories about Knud Rasmussen and er the other explorers er, that was a big adventure. So at the time for, in those days there was compulsory military service er, military service when you’d finished high school. So when I was eighteen, I had to do my duty for the my country. I volunteered for er Grønnedal which was a naval base in southern Greenland. And er they took me, so I spent 11 months on Grønnedal in er south Greenland. And er, I was taken in by Greenland and decided well, I’ll make myself a Greenland man and a Greenland life. How to do it? First I thought of meteorology but er, there seemed to be study there, pure mathematics. That was nothing for me. So I ended up with geology. So I really choose geology er, as my profession er not out of a special interest for geology but as a means to get to Greenland. And that seemed to work out quite well because as I said now I can calculate I had in total 42 summers field seasons in Greenland. I lived in Greenland for two years working as a mine geologist at the Black Angel Mine, and yeah, now I retired five years ago and here we are.
Yeah, so my, my, after my military career, which, I was really working hard being a waiter at the officers’ mess, standing there in, in my neat white uniform and er, when the officers, they put up three fingers in the air, I clicked my heels and brought them immediately three er bottles of beer. That was, was the life in, happy life in the naval station Grønnedal.
So I started to study geology and er, my first two field seasons in Greenland er, 64 and 67, I worked as a student helper or assistant with the Geological Survey of Greenland. And that was in South-West Greenland. And especially the second field season, around Paamiut, that was mapping of the Precambrian basement. And I was a helper. And I should walk behind the geologist and we were working in the area, making observations and main observations that was about the orientation of the rocks, dip and strike, which you measure with a compass and you can’t get enough of those measurements and er, noting of er, types of lithology and they are are all gneisses.
Julie 4:02
Gneisses are a typically banded or layered metamorphic rock.
Bjørn 4:06
And er, and I walked behind the geologist and carried his er rock samples and er, already in that time I had interest in, in economic geology. I like things to be used. So I started to go after the malachite staining, green spots on the rocks, indicating copper mineralization. I was immediately called to order by the geologist, saying, “we are not supposed to, we are the Government, we’re the State, we’re not supposed to look after er, economic minerals. We leave that to industry. Here at our survey, we do science.” So every night in the tent, we were working from a two-person tent camp, a common sleeping tent and a kitchen tent. So in the evenings we were sitting in the kitchen tent. I did the cooking. And the geologist, he was plotting up all his er measurements, I mean dip and strikes on a diagram. And by rotating the diagram, he could find the fold axis.
Julie 5:06
Plotting measurements on a Wulff net or steronet diagram like this is how geologists figure out the orientation of folds and other three-dimensional structures in rocks.
Bjørn 5:17
And the fold axis that was the big thing, the main thing. And er, the whole idea with that sort of mapping is to build up, all sorts of mapping, is to build up a chronology, that means, distinguish the oldest rocks from the youngest rocks and so to speak build a story. And er so here in an old terrane, you count how many times it’s been folded. And you do that with the help of, of er fold axes. And er, to make it short, I found that rather boring. And it was a long season, three months. And it was raining because Paamiut, that’s er, well a wet part of Greenland to put it in that way.
So after that I, I wrote a letter. I heard a lot about East Greenland. And I wrote a letter to a mining company who is operating over there called Nordisk Mineselskab, or short Nordmine. Er, or in English the Northern Mining Company. And that company had been running a lead zinc mine in central East Greenland er, at Mestersvig from 1958 to 62. And we are now in 68. They offered me a job doing prospecting in that area. And er, I was very happy about it. Then what’s happened, I was run down by a car in southern Norway, just before the field season, broke my ankle in four parts and er, was very sad. I thought now that was the end of my career as a field geologist. But they did a very good job here in, in Copenhagen. So the next year er, I went with that mining company to central East Greenland. And er, that was quite another story.
We were operating out of Mestersvig. We had one helicopter and about five, six, seven field teams of two persons and er, working out of field camps, camps being shifted by the helicopter every week or thereabouts. The other, all the other persons, they were Austrian mining engineers because the exploration manager, Erik Hintsteiner, very dynamic and charming and gifted young mining engineer, who had worked at the lead mine, he hired the whole staff in the back at his university at Leoben, Montanistischen Hochschule in Austria. And they were happy guys. And they were singing and shouting in the mountains. And they’d never heard about a Wulff net and, and I don’t doubt that they knew what a fold axis was, er at least not how to construct them. So we did prospecting. The first job was to er, we were a team of four er, using three weeks to dig a trench through a black shale enriched in copper, lead and zinc, of the contemporaneous and at the same time as the famous German Kupferschiefer,
Julie 8:10
The Kupferschiefer, which is German for copper shale, are sedimentary rocks that extend over a vast area of central Europe.
Bjørn 8:17
which had been an important source of especially copper since the Middle Ages in Europe. The occurrences are now in Poland. Anyway, we have found similar rocks and er, with similar mineralization in East Greenland. Problem was er, the sequence about 20m thick, it was situated on top of a steep mountain. And that sort of rock is, it’s very soft, that means it weathers. And when you sample er, you always need whatever type of geology you do, doing, either it’s science or economic geology, you want fresh rocks. And er, that black shale was covered about a metre of rotten rocks, that means weathered rocks, where you know by weathering processes some of the metals are removed and you don’t get a, a true impression of the, the er metal contents of the rocks. So you had to remove that. We did that in the trench by drilling, hand-held drilling called a Cobra and drilling holes and putting dynamite in. And “wheeet….bang!” And then we had to dig out the, the loose rocks. And finally, we had a very neat exposure one metre down, very steep. And er, we took by hand a channel sample through the whole sequence. That means with hammer and chisel we excavated er, five by five centimeter thick er furrow through the bottom of that, that trench, which was steeply inclined. Put them in bags and er, send them for the laboratory. And it later turned out that well, yes er, there’s copper, lead and zinc, and er, and a lot of other metals in there but not in economic concentrations. But er, it’s still interesting type of mineralization. And since that (series) one trench which we dug in 69, it’s not been investigated in any detail.
That’s a long time ago. That’s fifty years ago. I’m still alive.
Julie 10:14
I’m Julie Hollis and you’ve been listening to Polar Podcasts.
Julie 10:25
In the next episode, we hear more from Emeritus Professor Brian Upton about working on the unusual alkaline igneous rocks in South Greenland in the 1950s and later.