Open Positions

We are looking for M.S. students! See below for open research topics:


Investigating anisotropic petrophysical properties across the décollement in the Scandinavian Caledonies (COSC-2 – ICDP drill project)

The proposed research project is involved with the ICDP (International Continental Drilling Program) COSC-2 research consortium, focusing on a petrophysical characterization of the décollement in the Scandinavian Caledonides. The Scandinavian Caledonides dominate the geology of Norway and western Sweden with a NWSE extent of around 1750 km. Deep erosion during the latest stage of orogenesis and the absence of post-Paleozoic deformation offers a unique opportunity to study the interior of an orogen, providing insights into recent orogens such as the Himalaya, which is closely comparable to the former Caledonides. The Collisional Orogeny in the Scandinavian Caledonides (COSC) scientific drilling project takes advantage of this opportunity and aims to better understand tectonic processes in former and active orogens and to verify interpretations of the Scandinavian Caledonides made on the basis of subsurface geophysical investigations. 

The goal of the thesis is to characterize the petrophysical properties of the décollement and associated deformation zone found in the COSC-2 drill core, as well as the units above and the basement rocks below. 

The student will learn various laboratory measurements that are fundamental to petrophysical characterization. These techniques are often applied in reservoir exploration and engineering, tunnel construction, borehole stability, geophysical survey, so the student will be a part of both an applied and scientific project. 

Tasks: 

• Establish a testing protocol that would sample the representative rock types within the COSC-2 drill core. 

• Measure density, porosity, and minerology changes in core samples along the borehole. 

• Measure seismic velocity (p- and s-wave) on representative core samples (e.g., Wenning et al., 2016). 

• If time allows, measure permeability under various confining pressure conditions and/or frictional properties of the major deformation zone (see LabQuake device). 

• Relate the petrophysical properties to compositional changes and microstructure, and put in context with borehole/regional geophysical surveys, borehole stability analysis, crustal seismology, tectonic history. 

For further information please contact Claudio Madonna, Quinn Wenning, Markus Rast, Jonas Ruh.


Investigating the rheological comparison between epidote-rich vs epidote-poor eclogites

The proposed research project would investigate the role of epidote on eclogite rheology through microstructural and analytical analyses. Constraining eclogite rheology is critical in our understanding of subduction zone dynamics. Based on naturally deformed rock outcrops it is clear that epidote plays an important role on the deformation behavior of eclogites, as seen in the figure where epidote-rich eclogites produce tighter folds and accommodate more strain while epidote-rich eclogites have more open folds and accommodate less strain. 

The goal of this project is to characterize the deformation mechanisms within both epidote-rich and epidote-poor eclogites and then compare these results with hand-samples and outcrops while providing implications for the subduction zone rheology.

Tasks:

  • Use the petrographic microscope and scanning electron microscope (SEM) to characterize the deformation microstructures in a number of samples. 
  • Conduct various microstructural analyses using the SEM to infer deformation mechanisms in epidote, omphacite, and other minerals present. 
  • Relate microstructural relationships observed at the grain scale to hand samples, rock outcrops and subduction zone rheology

For more information, contact Leif Tokle with a CV and a short statement of interest.


Comparing the stress estimates from recrystallized grain sizes and subgrain sizes in naturally deformed quartz and/or olivine

The proposed research project would compare the estimated stress from existing recrystallized grain size and subgrain size piezometers for either quartz and/or olivine using a suite of naturally deformed samples in our groups existing collection. 

Estimating stress at depth where minerals flow rather than fracture is incredibly difficult yet critical to our understanding of large-scale geodynamic processes. The best technique we have to estimate stress is through a relationship between the recrystallized grain size or subgrain size and stress (which is empirically developed through rock deformation experiments); however, it is unclear whether recrystallized grain sizes and subgrain size piezometers provide the same or similar stresses as no one has ever compared the two types of piezometers on the same naturally deformed rocks.

The goal of this project is to measure both the recrystallized grain size and subgrain size in a suite of naturally deformed samples and compare the estimated stresses. Based on the results of this analysis one can discuss the implications of using and comparing stresses from recrystallized grain size and subgrain size piezometers.

Tasks:

  • Use the petrographic microscope to identify regions for sample measurements
  • Use the Scanning electron microscope (SEM) at the Hönggerberg campus to measure recrystallized grain size and subgrain sizes in samples.
  • Use matlab to process data collected in the SEM

For more information, contact Leif Tokle with a CV and a short statement of interest.