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My research in a nutshell

My research focuses on solid Earth geochemistry and the study of geochemical processes, ranging from low-temperature reactions such as scaling and fluid-rock interactions or heavy metal contamination to high-temperature environments involving mantle geochemistry, geochemical processes occurring in the crust and age-dating of zircons. My current focus is on the use of mineral alteration and mining waste as a possible sink for atmospheric CO₂ and general fluid-rock interactions.

Areas of research

Mineral alteration and weathering relating to carbon capture and storage means involving enhanced weathering processes

Recycling of building materials and mining waste for possible use in CO₂ mitigating processes for carbon capture and storage 

Mantle geochemistry and crustal processes affecting the geochemistry of basalts

Current projects, research interests, teaching activities and laboratory facility responsibilities

Enhanced weathering and carbonation of olivine

This project revolves around the use of olivine weathering as a mean for capturing and storing atmospheric CO₂. The project involves laboratory-based experiments on olivine-fluid reactions using various fluid types and various temperatures and CO₂ pressures. In addition to weathering experiments at ambient conditions, I also study the processes relating to carbonation of olivine resulting in the formation of magnesite, a Mg-rich carbonate phase capable of storing CO₂ over long periods of time. Moreover, I am currently developing experimental set-ups to be used for experiments mimicking the use of olivine as a mean for carbon capture and storage in the Danish nature.

This research is funded through the Independent Research Fund Denmark (through Kristoffer Szilas)

You can read more about this project on the following links:

Dansk: Mineralet olivin kan trække CO2 ud af atmosfæren – Københavns Universitet (ku.dk)

Mineralet olivin trækker CO2 ud af luften: Kan potentielt løse vores klimakrise – Københavns Universitet (ku.dk) 

English: The mineral olivine can extract CO2 from the atmosphere – University of Copenhagen (ku.dk)

Can an abundant green mineral solve our climate crisis? Exploring the power of Olivine – University of Copenhagen (ku.dk)

Potential for long-term CO₂ storage through enhanced weathering of Ca-silicate minerals and materials

This project will commence in December 2023 and focuses on the potential CO₂ storage posed by weathering and carbonation of Ca-Al silicate minerals and building- and mining waste associated with anorthosite mining. The project will be focused on laboratory-based experiments altering various Ca-Al silicate materials in the presence of CO₂ and water at various temperatures and pressure. The work will moreover involve developing geochemical models describing the alteration of such materials to evaluate their potential to capture and store CO₂ through enhanced weathering and carbonation.

This research is funded through the Independent Research Fund Denmark (starting from December 2023)

You can read more about this project on the following links:

Dansk: Forskningsprojekter — Danmarks Frie Forskningsfond (dff.dk)

Maja Bar Rasmussen modtager 2,9 millioner kr. fra Danmarks Frie forskningsfond - KUnet

English: Maja Bar Rasmussen receives DKK 2,9 million from Independent Research Fund Denmark (ku.dk)

Olivine chemistry, mantle heterogeneity and crustal processes affecting basalt geochemistry

This project relates to work during my PhD where I studied olivine chemistry variations and the importance of such variations to the mantle source beneath Iceland.  Olivine is usually the first mineral to crystallise during the ascent of mantle-derived melts and is stable over a large range in pressure, temperature, and melt composition. Because of this, the chemistry of olivine is often used as a proxy for primitive melt compositions prior to secondary modifications occurring in the uppermost part of the mantle and the crust. Iceland is the largest subaerial section of the global mid-ocean-ridge system and reflects the current location of the Iceland mantle plume. Previous work has shown that the mantle beneath Iceland is chemically heterogenous, and this has been attributed in part to the presence of recycled crust entrained within the upwelling plume. The recognition of a chemically heterogenous plume, together with the widespread occurrence of primitive basalts, makes Iceland an ideal location to identify the properties of recycled crust in a mantle plume from the chemical composition of high-forsterite olivine. 

I apply a combination of in-situ and bulk digestion analytical techniques to produce an internally-consistent, high-precision dataset for distinguishing mantle-derived variability from the effect of secondary processes, such as fractional crystallisation and assimilation. Examples of my previous work related to this subjects is:

Olivine chemistry reveals compositional source heterogeneities within a tilted mantle plume beneath Iceland - ScienceDirect

Helium and oxygen isotopic variations in the Iceland plume source controlled by entrainment of recycled oceanic lithosphere - ScienceDirect

Aside from the work on olivine chemistry, I study melt and mineral evolution of Icelandic basalts, from samples sampling the most enriched sources of the Icelandic mantle and fresh basalts from the 2021 and 2022 Fagradalsfjall eruptions.

Supervision, teaching and laboratory facility responsibilities

Current supervision of 1 BSc and 3 MSc students and one graduated MSc student (graduated November 2022)

In charge of the X-Ray diffraction laboratory facilities and mineral weathering laboratory (including a high-pressure titanium Parr reactor and facilities for enhanced weathering experiments)

If you have any queries, interest in collaboration or student projects, feel free to contact me through mr@ign.ku.dk