Cu-Co in space and time in the Viscaria Cu deposit (Cu-Co SPACETIME)

This project aims to determine the structural control, chemical character and age of representative type positions of copper-cobalt in the Viscaria Cu deposit in Kiruna.

The proposed project includes an interdisciplinary and state-of-the-art sample characterization workflow that spans a spectrum of scientific disciplines and involves collaboration and synergies between research groups at LTU as well as with external partners. Despite historical mining activities and recent extensive exploration at Viscaria, the deposit has been limitedly studied, and the age of the mineralization is still unknown. To develop effective and science-based exploration strategies for Viscaria-type copper mineralization, this project focuses on age determination of structurally and chemically well-characterized chalcopyrite-pyrite containing cobalt as a potential by-product. This project is well suited to be scaled up as part of a larger research project focusing on the exploration of critical metals driving the transition to clean energy.

One person working on the project is Edward Lynch, a postdoctoral researcher.

Where are you originally from, and what is your academic background?

“I am originally from County Donegal in North West Ireland. I received a PhD in Economic Geology in 2018 from the University of Galway for research on molybdenum-copper mineralization related to granite in Newfoundland, Canada. During my career, I have also researched other types of mineral deposits including porphyry copper, skarn-tungsten, metamorphic graphite, and iron oxide-copper-gold.”

What is the main focus of your research within the project?

“My project is called "Viscaria Cu-Co spacetime". The main goal is to determine the absolute age of the Viscaria copper deposit near Kiruna. The research involves detailed petrography, mineral characterization and radiometric dating of the mineralization.”

What attracted you to this specific research project?

“In terms of copper mineralization in northern Sweden, Viscaria is a bit of an outlier because we don't fully understand how the deposit was formed and when. So, my research project is an exciting opportunity to answer these questions about timing and origin that have not previously been addressed at Viscaria. Coming to LTU and working with colleagues in the ore geology group was also a big attraction for me.”

What are some of the main research questions or goals you are focusing on during your postdoctoral period?

“Firstly, we want to establish the timing of copper mineralization at Viscaria. One idea is that the copper formed at the same time as the volcanic rocks around 2100 million years ago during a phase of crustal expansion and thinning. Another idea is that the copper formed later during a period of mountain building, either 1900 or 1800 million years ago. Another aspect is whether all copper was introduced during a single mineralization event, or whether an earlier generation of copper was remobilized and reintroduced into the crust during later deformation. An additional goal is to assess the relationship between Viscaria and the iron mineralization that formed the Kiruna mine, as well as relationships with other copper deposits in Norrbotten - such as the Aitik mine. These are some of the questions we hope to address.”

Are there any specific skills or areas of knowledge that you aim to improve during your time in the project?

“I want to further develop my knowledge of the rhenium-osmium (Re-Os) dating method, both in terms of sample preparation and isotopic analysis. This technique is used to directly date sulphide ore minerals. The opportunity to develop new mineral characterization skills using analytical equipment available at LTU is also exciting. Overall, the project is a great opportunity to work on copper mineralization in northern Sweden and to think more broadly about the tectonic, magmatic and hydrothermal processes that formed this important ore province.”

How do you think the results of this project could have an impact, either locally or globally?

“Since the Viscaria deposit has not been dated before, we hope that any new ages will solve an important part of the "mineralization puzzle" in Norrbotten. Thus, the results will be of interest to the mineral deposit research community and exploration geologists, both in Sweden and internationally. In addition, there is usually a great interest from the global geoscience and exploration community for Swedish mineral deposits in general as Sweden is a key jurisdiction for mining in Europe. We hope that increased knowledge of the Viscaria deposit will also help guide copper exploration strategies in Norrbotten going forward.”

How do you think this postdoctoral project can contribute to the goal of the green transition?

“It is worth noting that in 2023, copper was classified as a strategic raw material by the European Union due to its importance in industrial applications and its use as an electrical conductor. If the green transition is to succeed and increased electrification is part of that process, more copper will likely be needed to achieve this goal. So, a deposit like Viscaria can contribute to a domestic supply of copper for Europe. A potential by-product of copper mining at Viscaria is the extraction of cobalt - a critical raw material and an important component of lithium-ion batteries. In my view, understanding the geological factors governing the distribution of critical and strategic raw materials in Europe's bedrock represents key knowledge for the green transition.”

What unique challenges or opportunities do you foresee working in northern Sweden?

“For most geologists, exposed bedrock is king! I mean, the more exposed bedrock we encounter in the field, the more likely it is that we can observe interesting minerals, petrographic features and rock relationships to help solve our research questions. But this is a challenge in northern Sweden because there are so few visible outcrops due to the glacial cover.

Fortunately, I will be working with Copperstone Resources during my project. Copperstone is working on developing the Viscaria deposit towards becoming a new mine and they will give me access to their drill core archive. Working with drill core makes petrographic observations and sampling much easier. Otherwise, it feels great to work in northern Sweden and conduct geoscience research relevant to the sustainable development of society.”