Nina Søager

Nina Søager

Assistant professor

2017 → Present: Assistant Professor, University of Copenhagen, Denmark

2016 → 2017: Postdoc, University of Copenhagen, Denmark        

2013 → 2015: Postdoc, Geomar, Kiel, Germany

2007 → 2013: PhD, University of Copenhagen, Denmark

 

The major subject of my research is constraining the processes of recycling of lithosphere and fluids through the Earths mantle by constraining the nature of magma sources. Moreover, I study magmatic processes such as fractionation, crustal melting, sulfide saturation and eruption mechanisms This is done through geochemistry of large igneous province and ocean island basalts (Cape Verde, Tristan and Gough Islands, Faroe Islands, Iceland) and geochemistry of arc, backarc and intraplate rocks from southernmost South America using Sr, Nd, Hf and Pb-double-spike isotopes, mineral-mineral and mineral-melt equilibria for magmatic temperature, pressure and fO2, geochemistry of olivines, spinels and olivine melt inclusions by microprobe and laser ablation-ICP-MS.

 

Current research

Explosive silicic volcanism in the Loicas Trough, Southern Andes. A Geocenter funded project with one PhD-student starting in autumn 2019 and open possibilities for master student projects. The study will focus on the geochemistry, volcanology and timing of the Quaternary silicic volcanic centres to constrain magma sources, magma storage conditions, relation to Andean margin tectonic processes and future volcanic hazards.

Miocene-recent volcanism and associated crustal melting in arc and backarc of the Andean Southern Volcanic Zone. Including an investigation of shallow subduction magmatism of the Payenia province and the relation between thrust faulting and crustal melting. Ultimately, the results should be coupled to the formation mechanisms of Andean giant Cu-Mo ore deposits.

 

Teaching responsibilities

Geology of the Lithosphere (2nd year geology bachelor course)

Basic Magmatic Petrology (1st year geology bachelor course)

 

Proposed student projects

  • Basaltic to rhyolitic volcanism in the southern Loicas Trough around the Tromen volcano. Identification of magma sources and magma storage conditions through major and trace element chemistry and isotope analyses.
  • Amphibole and clinopyroxene chemistry and thermobarometry in Miocene rocks from the Payenia province, Argentina. Investigation of the crystallization pressures and possible depths of crustal melting.
  • Zircon U/Pb-dating and trace element chemistry in Miocene-Pliocene lavas from the Payenia province, Argentina. A hunt for inherited zircons from the local basement to characterize the local basement and contributing magma sources.
  • Application of clinopyroxene thermobarometry to alkaline OIB rocks. Testing of the feasibilty of various thermobarometers on experimental alkaline melts and application on rocks from the Cape Verde islands. Do the plume melts fractionate at lithospheric mantle levels or not?
  • Olivine speedometry: How fast do magmas travel through the crust? Microprobe analyses of compositional profiles in olivines and modeling of diffusion of major and trace elements.
  • Mantle source lithology, temperature, oxidation state and sulfur concentrations/behavior in arc magmas from the Andean Southern Volcanic Zone. The study relies mainly on analyses of olivine and spinel compositions in the most primitive magmas by microprobe and laser ablation and the application of olivine thermometers and oxybarometers.
  • The lithospheric mantle of Cape Verde: a study of mantle xenoliths and megacrysts from Cape Verde including calculation of pressure, temperature and oxygen fugacity.

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