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 Christian Stenvall

Christian Stenvall

Research student,

Email:
stenvallca@cardiff.ac.uk
Location:
2.32, Main Building, Park Place, Cardiff, CF10 3AT
  • PhD Researcher - School of Earth and Ocean Sciences, Cardiff University, UK (2017-present)
  • MPhil - School of Earth and Ocean Sciences, Cardiff University, UK (2016)
  • BSc - Department of Geology, University of Otago, New Zealand (2015)
  • BBA - Arcada University of Applied Sciences, Finland (2012)

Research interests

  • Structural geology
  • Faults; Earthquakes
  • Deformation mechanisms
  • Strain localisation
  • and much more…

Thesis

Frictional-viscous deformation processes in the retrograde Kuckaus Mylonite Zone, Namibia

Although mylonitic shear zones are typically described as wide tabular zones of distributed deformation, the Kuckaus Mylonite Zone, Namibia, shows a pattern of localised strain in anastomosing ultramylonites, raising questions of what deformation mechanisms are active within mylonites, how these mechanisms are distributed, and how shear zones evolve with time.

A comprehensive microstructural study using scanning electron microscopy and image analysis will aim to quantify changes in the mylonites with increased strain to consider dominant strain localisation processes and deformation mechanisms at different stages of mylonitization. This will be followed by modelling the strength evolution of the shear zone based on mineralogical and microstructural evolution as defined from the microstructural study.

The observations will then be related to active shear zone deformation. For example, along both the San Andreas fault in California and the Alpine fault in New Zealand there are recent records of a range of seismic styles, from steady, plate boundary rate creep, through transient aseismic slip, to intermittent swarms of seismically detectable tremors. This range of behaviours, detected at depths several kilometres into the ductile mid- to lower crust, is enigmatic, and understanding of the underlying process requires observational data from exhumed shear zones from the 400 – 600 ˚C temperature range; the KMZ is an ideal example of such a shear zone.