In the project, he analysed the mineral compositions of Archean and Paleoproterozoic gneisses from the Nagssugtoqidian Orogen in West Greenland. Based on these analyses, he was able for the first time to constrain the pressure and temperature conditions during the metamorphism that affected the area around 1.8 billion years ago, in connection with the collision between the Rae and North Atlantic cratons.

The results show that the rocks reached temperatures of around 700750 °C at depths of nearly 35 kilometres. This also indicates that the area has since undergone extensive erosion.

The project was carried out in collaboration with GEUS, which collected the rock samples, as well as the University of Copenhagen and the University of Alberta, which contributed to the mineral analyses.

Read the article here: PT conditions of anthophyllite- and garnet-bearing metapelites of the Nunatarsuaq domain, Nagssugtoqidian orogen, West Greenland | GEUS Bulletin

And if two layers in the cake are the same colour, it can be difficult to see where one ends and the next begins.

Of course, you could taste your way through it but that would rather ruin the cake.

Archaeologists face much the same problem during excavations. Soil layers can be difficult to distinguish from one another, sometimes forcing archaeologists to dig into them simply to find out what they contain.

Researchers from Aarhus University and Moesgaard have now developed a relatively inexpensive camera system using LED light that can give archaeologists an extra way of looking at the soil before the trowel takes over.

The system illuminates the same surface with different wavelengths of light and can highlight differences between layers and materials that are difficult to spot. This can give archaeologists clues about what deserves closer attention and where it may be useful to take samples.

There are surprisingly many challenges involved in looking at soil. We wanted to make things faster, clearer and better while keeping the system affordable for use in the field. It is simply a way of rethinking the light, says Professor Søren Munch Kristiansen from the Department of Geoscience at Aarhus University.

The system is called LEDMSI LED multispectral imaging and is described in a new study in the Journal of Archaeological Science.

16 different ways of looking at the same soil

Instead of relying only on the light our eyes can see, the system photographs the same surface repeatedly while the multispectral flash illuminates it in turn with LED light at 16 different wavelengths.

The wavelengths range from near-ultraviolet through visible light to near-infrared.

Different materials absorb and reflect light differently. Two soil layers or tiny archaeological finds that look identical to the human eye may therefore behave differently when illuminated with other parts of the light spectrum.

The computer then combines the information from the images and makes some of these differences stand out more clearly.

You might say that the system tastes the layered cake with light.

Tested at Sorte Muld

The researchers tested the first prototype at Sorte Muld, an Iron Age site on the Danish island of Bornholm.

Here, thick, dark cultural deposits lie on top of one another after centuries of human activity. For an archaeologist, it can be difficult to determine exactly where one layer ends and another begins.

With the first prototype, the researchers could not analyse the results while they were still at the excavation.

The images looked almost psychedelic, and we only really saw the result when we came home and analysed them on the computer. But then we could see new layers and changes in the fill that we could not see with the naked eye, says Søren Munch Kristiansen.

The multispectral analyses revealed differences in the sediments and stratigraphic boundaries that did not stand out clearly in ordinary colour photographs.

The computer could not tell the archaeologist exactly what each individual layer was. But it could point out that something was different.

And that is the next step in the development: not only revealing the differences, but also helping archaeologists understand them while they are still in the field.

From Bornholm to graves in northern Jutland

Since the test at Sorte Muld, the system has been further developed.

A newer and faster version with two LED units and an improved camera has recently been tested at Fredbjerg in Vesthimmerland, northern Jutland, as part of the IDUN project. Here, archaeologists are investigating a cemetery dating from the late Viking Age and early Christian period.

Preservation conditions are poor, and the skeletal material has almost completely disappeared in some graves.

The skeletons could almost only be seen as shadows after a thousand years in the ground. So it is not always obvious where you should look or take your samples, says archaeologist David Stott from Moesgaard, who has helped develop the system.

At Fredbjerg, the multispectral images were not merely used to show differences. They were also used to plan where samples should be taken.

We used the new data to plan our sampling. The camera could show us areas where it was most relevant to look for example for remains of bone or material from the area around the abdomen, says David Stott.

The Fredbjerg experiment is not part of the published Sorte Muld study, but is a test of the next generation of the system.

Soil does not come in neat layers

This kind of assistance can be important because archaeological deposits rarely resemble a tidy stack of pancakes.

People have dug holes, filled them in again, moved soil around and built on top of earlier activity. Objects found in different layers may therefore come from the same period. Conversely, things lying close together may be very different in age.

If we can see more clearly how soil was dug up and deposited again, we get both better documentation and a better understanding of the site. It can also help us choose the right places to take samples for things such as dating, says Søren Munch Kristiansen.

Now the computer has to learn what it is seeing

The first prototype could take up to around five minutes to capture a series of images. The newer version tested by David Stott at Fredbjerg can complete the full sequence in around 30 seconds.

The next step is to process the images almost in real time on a computer and perhaps eventually on a smartphone while the archaeologist is still in the field.

But the researchers want to do more than simply display the differences quickly.

They are also working on software that uses machine learning to recognise patterns in the multispectral images and help archaeologists work out what is what in the soil profile.

The difficult part is teaching an algorithm to understand what is what. That is something we will start working on in the coming versions, says Søren Munch Kristiansen.

The idea is not for the computer to replace the professional judgement of archaeologists or geologists. Rather, it should act as an extra pair of eyes, pointing out areas that may resemble bone, particular types of soil or other materials that deserve closer examination.

As Søren Munch Kristiansen puts it:

At the moment, the problem is that the archaeologist and I, as a geologist, basically have two settings: glasses off or glasses on.

He hopes that systems like this will eventually become standard equipment on archaeological excavations.

I hope that in ten years, bringing a system like this to an excavation will be as normal as bringing a digital camera, he adds.

For now, however, there is one very practical limitation:

The measurements require other light to be kept out.

So Søren Munch Kristiansen has invested in a rather less high-tech accessory: 100 metres of the kind of black plastic farmers use to wrap silage.

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The new study resolves a long-standing mismatch between indices of timing of the first Eurasian Ice Sheet expansion in terrestrial and marine records by dating the earliest known glaciogenic sediments in northwest Europe, the Hattem Bed Complex in the Netherlands. Burial dating with cosmogenic ²⁶Al-¹⁰Be and detrital zircon fingerprinting indicate that the Fennoscandia-sourced Hattem gravels reached the Netherlands by ~ 2.4 Ma, while ages from the overlying Appelscha Formation record a second ice-sheet advance and glacial destruction of the former Baltic River System at ~ 1.7 Ma. 

The new results represent a major departure from the traditional interpretation of the glaciogenic sediment record in northern Europe, because it implies the Eurasian Ice Sheet reached a continental-scale size more than 1 million years earlier than hitherto believed. However, the new ages accord with estimates from North America showing that the Laurentide Ice Sheet reached its maximum extent in northern USA ~2.4 million years ago. 

There was a sense of joy, pride and reflection as the Department of Geoscience celebrated this year's graduates at its traditional graduation ceremony.

Head of Department Marit-Solveig Seidenkrantz congratulated the new bachelor's and master's graduates on their achievements and reminded them that working life will bring both successes and challenges

- "We are proud of you and excited to see what you will go on to do. There will be both ups and downs, but your education has given you a strong foundation that will help you overcome them," she said.

Director of Studies Ole Rønø highlighted the hard work required to complete a university degree and the personal development he has had the pleasure of witnessing throughout the students' years at the university

- "It has been hard work, but you have succeeded in earning your degree. I have enjoyed getting to know you and following your development. Now you are ready for working life," he said.

The ceremony's alumni speaker, Marie Svendsen, shared her experiences from life after graduation. She spoke about travelling, taking the first steps into the job market and the steep learning curve that comes with the transition from student to professional.

Her message to the graduates was clear

- "There is no typical path. There is no right path. There is your path."

On behalf of the graduating class, Pernille Runge Jørgensen delivered the student address. She reflected on the strong sense of community that had grown over five years of study and the bittersweet feeling of now going their separate ways.

- "For the first time in five years, we won't be meeting in the classroom, over lunch or at Friday bar. But we figured it out together, and I'm sure we'll continue to find our way forward," she said.

The Department of Geoscience congratulates all of this year's graduates on completing their degrees and wishes them every success in the next steps of their individual journeys.

Marit-Solveig is among the 30 new members admitted to the Academy in June 2026. The election is a recognition of outstanding scientific contributions and at the same time reflects the breadth that the Academy strives to achieve across research fields.

Marit-Solveigs research lies within past climate and ocean circulation, marine geoscience, micropaleontology, multiproxy investigations. She has a particular focus on understanding the climate system in particular the ocean circulation and tis interaction with the atmosphere and cryosphere. She is internationally recognized for her expertise in palaeoceanography in the Greenland and North Atlantic region.

As a member, Marit-Solveig will become part of a strong interdisciplinary community working to strengthen research for the benefit of society. Here, members contribute through committees, panels, and projects to help shape and advance the research agenda in Denmark.

This was clearly demonstrated at this years Nature Meeting, where 3,0004,000 of the total 30,00035,000 visitors stopped by Aarhus Universitys stand. Here, the Department of Geoscience invited guests to engage directly with research through a range of activities and events such as Be a geologist for a day and Geological treasure hunt  and guided landscape tours.

Outreach students from Geoscience together with associate professor Søren M. Kristiansen helped create dialogue, communicate scientific knowledge, and make complex topics about Earths history, climate, and landscapes accessible to a broad audience.

The PhD environment includes around 25 students working on a broad range of geoscience topics, including palaeoclimatic reconstruction, seismic analysis, and climate mitigation science. Across research groups, a shared community has been built through initiatives such as academic lunch meetings, buddy schemes and social events, which help ensure knowledge exchange and allow new researchers to quickly find their footing.

"We have created an environment where we can share our ideas, challenges and achievements - where we celebrate and support each other through the highs and lows of a PhD," says Sophie Vidal, PhD student, who accepted the recognition on behalf of the group. 

The department has worked strategically to foster an inclusive culture, where early-career researchers thrive and develop across disciplines.

Head of Department Marit-Solveig highlights the importance of this strong pipeline: Nurturing talent and maintaining a vibrant environment for younger researchers is essential to our department. It is here that we gain the creative energy that drives both our research and our teaching.

The department will continue its focused efforts to provide strong conditions for high-level research and to support the next generation of researchers in realising their full potential.

The collaboration has recently given the researchers access to unique core material from one of Energinets major offshore wind areas in the North Sea.

The cores are up to 70 metres long and contain sediments from the Holocene, Weichselian, Eemian and Saalian periods. This gives researchers and students an opportunity to investigate and learn more about the geological development of the North Sea during the latter part of the Quaternary Period.

The material may provide new insights into the environment, geology and former landscapes of the North Sea. This includes Doggerland, the former land area between Jutland and England where Stone Age people lived before the area was submerged.

At the Department of Geoscicence, Professor Katrine Juul Andresen is already working with data from the surveys together with two PhD students, a postdoc and several Masters and Bachelor's students. She expects more students to work with the material in the coming years. 

This is a good example of how collaboration between universities and industry can strengthen research, teaching and talent development while ensuring that existing data and samples are used to generate new knowledge.