•••  thermodynamics and kinetics of silicates, metal oxides and sulphides
                 - solubility (e.g., gold, iron and arsenic in hydrosulphide solutions)
                 - nucleation and growth rates  of metal oxides and sulphides (e.g., Fe-S, As-S, Fe-OOH (+-SO₄), SiO₂)
                 - surface characteristics and dissolution rates on mineral phases (e.g., pyrite)
                 - biomineralization, (biosilicification, magnetotactic bacteria)
                 - pyritization of hydrothermal vent faunas
                 - fate of metals during the transformation of ferrihydrite at low to hydrothermal temperatures
                 - green rust formation and stability
                 - carbonate nucleation and growth
                 - selenium geochemistry
                 - weathering of mineral phases by fungi

• field related projects

         •••  biogeochemical processes in active geothermal systems and in arctic and alpine Mars analogue settings
                - Taupo Volcanic Zone, New Zealand
                - AMASE (Arctic Mars Analogue Svalbard Expeditions)
                - Iceland
                - Deep Sea vents

• methods and analytical techniques:
                 - low temperature batch and flow through reactors (25-95°C, 1 bar)
                 - hydrothermal autoclaves (100-300°C, 500 bar)
                 - chemical analysis and characterization: ICP-MS, AAS, XRD, XRF
                 - light scattering and high-resolution microscopy: DLS, FEG- and E-SEM, cryo and HR-TEM
                 - surface characterization (FEG-SEM, Vertical Scanning Interferometry -VSI)
                 - synchrotron radiation (ED-XRD, SAXS/WAXS, FTIR, XAS)

• group members  and their projects

Metal oxides and sulphides

• stability and transformation kinetics of iron mono- and di-sulphides (mackinawite, greigite, pyrite) in low temperature (25-95^oC), reduced aqueous H₂S solutions.
 


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• Formation and transformation of metal sulphides (Fe-S, As-S phases) in hydrothermal solutions observed by synchrotron-based energy-dispersive X-ray diffraction (ED-XRD)
 


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• 3D evaluation of changes in surface topography on {100} cubic faces of pyrites are evaluated using Vertical Scanning Interferometry (VSI)  sas part of the PhD project of Ellen Avery; the goal is to to determine quantitatively the rates of pyrite oxidation in systems that mimic conditions at sea floor hydrothermal vents. 
 


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• Nucleation and growth of schwertmannite (an iron oxihydroxisulphate phase forming in AMD settings) from solution, studied via stopped-flow anf flow through synchrotron-based small and wide angle X-ray scattering (SAXS/WAXS);  
• this is Lois avidson;s PhD project
  
• Kinetics and dynamics of the nucleation and growth of silica nanoparticles in solution via a combination of synchrotron-based SAXS, dynamic light scattering (DLS) and cryo and high-resolution microscopy;
  
• this is Dominique Tobler's PhD thesis project;
  

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Silicification of cyanobacteria

 
• The processes and factors controlling biogenic silicification at temperatures below 90 °C is studied using batch and flow through reactor systems combined with laser scattering and high-resolution microscopy. The goal is to determine the kinetic rates of silicification and to establish the role and the mechanisms by which cyanobacteria and /or the organics on the surfaces of microbes influence the rate of silica formation. 

Fieldwork related projects related to modern Geothermal Systems

 
• New Zealand: determination of the silicification processes connected to biomineralisation in active sinter forming environments (Rotokawa, Waiotapu, Ohaaki-Broadlands) in the North Island of New Zealand; collaborative work with B. W. Mountain at The Wairakei Research Laboratory, Taupo New Zealand and Kurt O. Konhauser in Geology, at the University of Alberta (Canada).

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• Iceland: in situ silicification processes and silica sinter formation and links to biomineralisationprocesses in active sinter forming environments - collaboration with Andri Stefansson Iceland); geochemical and genomic analyses;
  
• PhD thesis of Dominique Tobler
  

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• AMASE (arctic Mars Analogue Svalbard Expeditions)