Projects Section 3.3

 

Determination of PVTx properties of dense H2O+NaCl solutions to 5 GPa, 600°C, and 50 wt% NaCl

Determination of molar volume, refractive index, sound velocity, and liquidus in the system H2O+NaCl to 5 GPa, 600 °C, and 50 wt% NaCl using Brillouin spectroscopy and a hydrothermal diamond-anvil cell

Computational Geomaterials Research

Atomic-scale modeling techniques are used to study the properties of
geomaterials from first-principles, i.e. without experimental input.

DFG SPP 1236

Central to the SPP project will be studies on silicates, oxides, carbids, carbonates and nitrides based on in situ experiments performed at very high pressures and temperatures (> 10 GPa, > 1000 K) in either laser heated diamond anvil cells or multi-anvil devices, and complementary quantum mechanical model calculations.

Dense hydrous magnesium silicates (DHMS)

We synthesize dense hydrous magnesium silicates (DHMS) under P-T conditions of the Earth’s mantle and investigate them by spectroscopic and X-ray methods to get insight in their crystal chemistry and phase relations.

Incorporation of H+ in nominally anhydrous minerals

We synthesize and characterize nominally anhydrous minerals, which have incorporated traces of hydrogen in their structures: e.g. coesite, clinopyroxene, olivine, wadsleyite and ringwoodite.

Elastic Anisotropy of Ferropericlase in Earth`s Lower Mantle

We are determining the elastic anisotropy of minerals under lower mantle pressures in a diamond anvil cell to improve our understanding of the structure, composition, and dynamics of the deep Earth interior.

Elasticity of cement crystalline phases

We are systematically exploring the mechanical properties of crystalline phases of cement (sulfates, hydroxides, silicates) in order to develop quantitative models able to predict the behavior and properties of concrete as complex multi-component system.

Fe spin transition in the lower mantle phases

We are investigating the effects of electronic spin-pairing transition of Fe on the mechanical properties of the main minerals of the lower mantle. This is essential to model the structure and dynamics of the deep Earth interiors based on global geophysical data.

FOR 741 "Nanoscale processes and geomaterial properties"

The intended research will focus on atomic and molecular scale processes at grain- and phase boundaries under pressure and temperature conditions of the Earth’s deeper crust and mantle.

The boron and lithium cycles

The distribution of Li, B and its isotopes between relevant minerals and fluids are determined by high-pressure experiments to better understand geochemical signatures and processes in subduction zones.

Solubility of HFSE-minerals and speciation of HFS-elements in aqueous fluids at high temperatures and pressures

Determination of HFS-element contents (Zr, Ti) in fluids in-situ at P and T using synchrotron-XRF. Characterization of HFSE-complexation in the fluid by X-ray absorption spectroscopy (XAFS).

High-grade fluid metasomatism in the lower crust and upper mantle

In this study the high-grade fluid metasomatism in the lower crust and upper mantle is investigated by combining experiments simulating metasomatism and by characterization of natural samples.

In-situ studies on heavy elements in aqueous fluids and melts at high pressures and temperatures

In-situ analyses of heavy elements in aqueous fluids and melts at high P and T using diamond-anvil cells and synchrotron radiation-XRF and XAS: studies on solubility, interaction kinetics, complexation, fluid density

Kinetics and the extent of immiscibility in basaltic liquids (DFG grant Fr 557/23-1)

The kinetics of melt unmixing is studied by means of high temperature centrifugation, measurements of viscosity and interfacial energy, Brillouin spectroscopy, small angle X-ray scattering, and the analysis of droplet size distribution.

Portlandite

The elastic properties of portlandite, which is an important compound of cement, was examined at high pressure by means of diamond anvil cell and multi anvil apparatus (MAX 2000) measurements at the synchrotron source HASYLAB in Hamburg.

Raman spectroscopic studies of aqueous fluids at high pressures and temperatures

Raman spectroscopic studies of aqueous fluids (complexation and speciation of dissolved elements, solubility, phase transitions) at high pressures and temperatures using hydrothermal diamond anvil cells

REE-phosphate minerals as monitors of geodynamic processes

Apatite, monazite and xenotime are common accessory minerals in most igneous and metamorphic rocks. Experiments and investigations on natural samples are focused on important questions including geochronology, thermometry, and metasomatic processes.

Silicate glasses

Structural and elastic properties of silicate glasses with compositions of the most important components of the Earth mantle are investigated at the relevant deep Earth pressures. Sound velocity measurements are used to determine in situ high-pressure density.

Spectroscopic studies on meteorites

Variously colored micro-grains of natural ringwoodite in shock metamorphism veins of thin sections of two S6-type chondrites were studied by means of microprobe analysis, TEM, Raman- and optical absorption spectroscopy.

Trace element cycle of subduction-related serpentinites

This project is aimed to better understand the role of serpentinites for the geochemical cycle of fluid mobile trace elements and their isotopes in the range of subduction zones.

Thermodynamic properties of complex fluid phases at georelevant P-T conditions

Fluids of complex composition have direct impact on most processes within the earth. For the understanding and modelling of such processes the thermodynamic properties of these fluids are required.

Interactions between aqueous fluids and silicate melts - distribution of trace elements

Determination of partition coefficients as a function of T, P and the composition of the fluid and granitoid melts. Comparison of quench-experiments and in-situ experiments using synchrotron-XRF.