Emil Aarestrup

Emil Aarestrup

PhD fellow

My research interests have revolved around igneous geochemistry and petrology, especially basalt petrogenesis and the insight it provide into mantle source lithologies, with more recent endeavours touching upon cumulate processes and metamorphic petrology. I have conducted field work in Scania, southern Sweden, Iceland and south-west Greenland. 

The Scanian project investigating the petrogenesis of intraplate, rift-associated Mesozoic primitive basanites. This project involved analyses of primitive olivine cores analysed using electron microprobe (EMP) with a high-precision setup, as well as trace element modelling.

On Iceland, we collected a large database for the Katla volcano. I subsequently chose a subset of samples and analysed these for Sr-Nd-Pb isotopes, which was used in conjunction with bulk rock major- and trace element geochemistry to characterise the Katla mantle source.

I am currently working on Archean layered mafic-ultramafic complexes in SW Greenland. These projects will involve new EMP analyses, LA-ICPMS mineral analyses and bulk rock major- and trace element characterisation. The new data will allow a characterisation of igneous processes and the metamorphic history/overprint using geothermobarometry and pseudosections. The Re-Os system will be used to provide better time constraints on the intrusion of the complexes.

Primary fields of research

  • Basalt petrogenesis
  • Mineral geochemistry
  • Geochemistry
  • Cumulate petrogenesis
  • Metamorphic petrology

Current research

I am currently working on Archean layered mafic-ultramafic complexes in SW Greenland, with special emphasis on the Amikoq Layered Complex. These projects will involve new EMP analyses, LA-ICPMS mineral analyses and bulk rock major- and trace element characterisation. The new data will allow a characterisation of igneous processes and the metamorphic history/overprint using petrography, mineral data, geothermobarometry and pseudosections. The Re-Os isotopic system will be used to provide better time constraints on the intrusion of the complexes.

Project dates: 2019-2021

Supervisor: Kristoffer Szilas

PhD study funded by the Villum Foundation (https://veluxfoundations.dk/en)

1.) Metamorphic conditions of the Mesoarchean Amikoq Layered Complex, SW Greenland: Igneous, metasomatic and metamorphic amphiboles and amphibolite-granulite facies metamorphism

The intrusive mafic-ultramafic Amikoq Complex is one of the largest Mesoarchean complexes in SW Greenland and hold important insights into early Earth processes, particularly on the dawning of modern style plate tectonics. However, prior to the extraction of any confident igneous interpretations, it is key to characterise metamorphic overprint. We present new EMP data and detailed petrography on 12 representative samples, with the aim of characterising the metamorphic conditions and amphibole provenance. Much of the noritic complex contain a relict igneous mineralogy, owed to a largely anhydrous high-grade metamorphic history. Granulite to amphibolite facies retrogression resulted in local replacement of relict high-T mineral assemblages by hydrous assemblages, due to the introduction of fluids. Our study demonstrate that even high-grade poly-metamorphic terranes can retain relict igneous mineralogy.

In cooperation with: Taus R. C. Jørgensen (Laurentian University, Canada), Paul Armitage, Allen Nutman (University of Wollongong, Australia), Ole Christensen

2.) The Mesoarchean Amikoq Layered Complex, SW Greenland: Primitive orthopyroxene-plagioclase dominated cumulates derived from boninite-like or contaminated high-Mg parental melts?

We present bulk rock major- and trace elements on a large sample collection from the Amikoq Layered Complex and hosting supracrustal metabasites. Plausible parental melt(s) will be investigated through trace element modelling with implications to geodynamical settings.

In cooperation with: Iain McDonald (Cardiff University, United Kingdom), Paul Armitage

3.) Plagioclase and orthopyroxene crystallisation in a Mesoarchean intrusion: Insight from drill cores

This study will present detailed petrography, EMP and LA-ICPMS mineral data on drill cores of the Amikoq Layered Complex, SW Greenland. The aim of the project is to investigate igneous processes related to Mesoarchean plagioclase and orthopyroxene cumulates and will provide new constraints on parental melt(s).

4.) Rhenium-Osmium isotopic and platinum group element constraints on petrogenesis of Archean mafic-ultramafic intrusion, SW Greenland.

Re-Os isotopic and PGE data will be presented on several Archean mafic-ultramafic intrusion of SW Greenland, with an emphasis on the Amikoq Layered Complex. The Re-Os system provide quantitative model dates on the intrusions, while the PGE’s can be used to trace mantle melting processes and cumulate processes.  

In cooperation with: Graham Pearson (University of Alberta, Canada)

ID: 165824334