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 Experimental and Theoretical Petrology
Last Update
25.10.2017
 

Scientific profile



Main research area: Experimental and theoretical petrology and geochemistry

The principal research is oriented towards understanding processes in the silicate mantle and crust of terrestrial planets. Processes of interest are for example dynamically and kinetically driven nano- and micro-scale transport mechanisms, mineral-fluid-melt disequilibria, large scale mass transport and magma differentiation during melt-rock and melt-melt events, but also physico-chemical interaction processes between pressed-in CO2 with circulating saline fluids and host rock to evaluate potential risks created by underground deposits of pressed-in CO2 or investigations of environmentally important natural and anthropogenic mineral phases containing toxic elements, using modern methods of crystal chemical characterization and low-temperature thermodynamic modeling. Lately an additional focus is on nano-polycrystalline materials, e.g., ceramics, with excellent mechanical properties, as for instance high hardness and high fracture toughness, from Earth’s high abundant geomaterials. Furthermore the interest is in the early history of planets and planetesimals, namely accretion and mantle-core separation scenarios of the Earth, other terrestrial planets (e.g., Mars), and planetesimals. The tools of the research are concepts of theoretical and experimental petrology and geochemistry. For example physico-chemical interaction processes between coexisting silicate, sulfide and/or metal phases, which play an important role during the accretion and differentiation, are studied in detail. The results of these studies can be used to model differentiation trends of basaltic systems and to model the genesis of magmatic sulfide ore deposits as well as to shed some light on core-mantle separation processes in the early history of terrestrial planets.



Examples of current research projects

  • physico-chemical interaction processes between coexisting silicate, carbide, sulfide, and/or metal phases
    - textural equilibria of iron sulfide liquids in partly molten aggregates at elevated temperature and pressure
    - partition behavior of siderophile and chalcophile elements during early history of planets and planetesimals
    - fractionation of platinum group elements during mantle melting
  • physico-chemical interaction processes between coexisting mineral phases, fluids and/or silicate melt phases
    - dynamics and kinetics of melt-fluid-rock interactions
    - micro- and nano-scale interactions of mineral phases with melts and fluids
    - fluid-solid and fluid-melt-solid partition coefficients of fluid-mobile elements. The partition coefficients will help to specify the element contributions of the different components of the subducting slab (slab mantle, basaltic oceanic crust, sediments) to the element budget (LILE, REE, HFSE) released from the slab
    - seawater-rock (MORB) interaction and resulting element partitioning in supercritical hydrothermal systems
  • physico-chemical interaction processes between pressed-in CO2 with circulating saline fluids and host rock’s mineral and cement phases
    - chemical reactions of pressed-in CO2 with circulating saline fluids and mineral and cement phases of the host rock
    - alteration processes of cap rock textures due to percolating CO2-enriched brines
    - microtextural changes of reservoir rocks due to alteration processes at pressure and temperature conditions of CO2 underground deposits
    Information about the kinetics of the studied reactions (i.e., interactions between fluid-fluid, mineral-fluid and mineral assemblage-fluid phases) can be derived from the experimental data. Furthermore, the alteration of rock textures as a function of time can be deduced. The use of these data as input parameters for computational simulations will help to evaluate potential risks created by underground deposits of pressed-in CO2.
  • physico-chemical interaction processes between coexisting mineral phases and fluids (e.g., meteoric water)
    - crystal chemistry and thermodynamics of environmentally important natural and synthetic phases containing toxic elements
    It has long been recognized that the bio-availability and mobility of toxic elements (e.g., Se or As) in the environment are controlled by their speciation, i.e., their structural and chemical properties, such as oxidation state, coordination, nature of ligands, complexation, etc. However, what is still lacking is a profound understanding of the interplay between structural characteristics and thermodynamic stability of toxic mineral species. The major goal of the project is thus to correlate the physico-chemical stability of low-temperature secondary mineral species containing Se or As with their respective structural characteristics.
  • synthetic nanocomposite ceramics – tailored alternative materials
    - nano-polycrystalline geomaterial composites with excellent mechanical properties made of economical non-critical materials
    State-of-the-art high pressure technologies allow synthesizing nano-polycrystalline materials, e.g., ceramics, with excellent mechanical properties, as for instance high hardness and high fracture toughness, from Earth’s high abundant geomaterials (SiO2, Al2O3). Thus, nano-polycrystalline geomaterials have high potential to substitute economical critical metal raw materials that are essential for the production of common materials with enhanced mechanical properties.
  • differentiation of basaltic melts with the main emphasis on the origin of SiO2-rich residual melts
  • 3D analysis of rock textures (X-ray micro computer tomography)
  • high-temperature solution calorimetry and differential scanning calorimetry