Geo- and Cosmochemistry

Projects

• Ion Probe Cameca IMS 1280-HR
  • Oxygen 3 isotope measurements of chondritic silicates and carbonates
  • Simultaneous oxygen and carbon isotope measurements of chondritic carbonates
  • Oxygen and carbon isotope measurements of speleothems
  • ⁵³Mn-⁵³Cr dating of chondritic sulfides and carbonates
  • Carbon isotope measurements of graphite inclusions in zircon
  • Carbon isotope measurements of meteoritic graphite
  • U-Pb-Pb dating of phosphates in chondrites and achondrites
  • U-Pb-Pb dating of Martian baddeleyite
  • U-Pb-Pb dating of zircons (incl. impact metamorphosed)
  • Nuclear forensics (in cooperation with KFZ Jülich)
• Klaus Tschira foundation: Professorship for analytical and theoretical cosmochemistry
• Ice Weathering Analysis in Support of the JUICE mission (ESA)
• Origin of life: Formation of prebiotic organic molecules in the Earth’s crust (FRONTIER - programme of the Universität Heidelberg)
• DFG Schwerpunktprogramm 1833: "Building a Habitable Earth"
  • Outgassing history and early atmospheric processes recorded by paleoatmospheric noble gases in Archaean rocks (DFG GEPRIS)
  • Biogenic Carbon in Magmatic Minerals and Implications for the Preservation and Obliteration of Hadean Isotopic Biosignatures (DFG GEPRIS)
• DFG Priority Programme 1385: "The first 10 Million Years of the Solar System - a Planetary Materials Approach" (UniSpiegel, DFG GEPRIS)
  • Coordination (DFG GEPRIS)
  • Project: I-Xe and Ar-Ar chronology of enstatite chondrite and enstatite achondrite parent bodies in the Early Solar System (DFG GEPRIS)
  • Project: Simulation of high speed capture of interstellar grains (DFG GEPRIS)
  • Project: Modelling the internal constitution and thermal evolution of planetesimals and applications to geochronology (DFG GEPRIS)
  • Project: Gravoturbulent Planetesimal Formation in the Early Solar System (DFG GEPRIS)
  • Project: Pre-exposure to cosmic rays of chondrules and Ca-, Al-rich inclusions (DFG GEPRIS)
  • Project: Primordial noble gases in micrometeorites (DFG GEPRIS)
  • Project: Kurzlebige Isotopensysteme in Sulfiden von Enstatit-Chondriten (DFG GEPRIS)
  • Project: ¹⁰Be-¹⁰B systematics of chondrules and refractory objects in primitive chondrites (DFG GEPRIS)
• Edelgasisotopenzusammensetzung des präkambrischen Erdmantels (HO2591/7)
• Project "The petrology, geochemistry and age determination of impact melt from the USGS-ICDP drill core Eyreville-B into the late Eocene Chesapeake Bay impact structure " (SPP 1006)
• Project "Risk assessment of large meteorite impacts" (german site) (Klaus Tschira Stiftung gGmbH)
• Noble gases in UHP eclogites and peridotites of the CCSD core (ICDP, CCSD, DFG TR333/9)
• STARDUST: Simulation of Interstellar Grains in the Laboratory (FRONTIER - Fond of the Heidelberg University (funded within Excellence Initiative))
• Noble gases in the global element cycle: Fluid transport into the deep mantle by subduction processes (DFG HO2591/3-1)
• Ar isotope dating (⁴⁰Ar-³⁹Ar, ⁴⁰Ar-³⁸Ar) for calibrating K-Ar and U-Pb-Pb age scales (DFG TR333/8)
• In situ instrument for radiometric dating of planetary surfaces (ISAGE) - cooperation with Kayser-Threde, Munich
• DFG Research group 759 "The Formation of Planets: The Critical First Growth Phase"
  • Project A1: Laboratory experiments of thermal annealing, evaporation and condensation of dust
  • Project B3: High temperature dust collision experiments
• Cooperation with Synthetic Quantum Systems group des Kirchhoff Institute for Physics ³⁹Ar detection via Atom Trap Trace Analysis (ATTA)

Research interests

• Geochemistry (particular noble gas isotope systematics), petrology and mineralogy of the terrestrial mantle, mantle geodynamics, origin and evolution of the Earth
  • Accretion and early differentiation of the Earth, formation of atmosphere, mantle and core
  • Interaction of terrestrial mantle and crust; subduction of lithospheric components
  • Isotopic characterisation of deep mantle plume reservoirs of ocean island basalts (Hawaii, Iceland, Réunion) and flood basalts (Eritrea, Deccan traps, Siberia)
  • Petrology, mineralogy, geochemistry and noble gas isotope systematics of the subcontinental lithospheric mantle: Ultramafic rocks from the east African rift system (Red Sea, Kenia), central europe (Eifel, Pannonian Basin) and South Africa, CCSD drilling project Donghai. Geochemical identification of mantle plumes in the subcontinental mantle
  • Microdistribution of noble gases in basalt glasses and mantle xenoliths, transport processes via mantle fluids, metasomatism
  • Diffusion of noble gases in solids
  • Noble gases in interplanetary dust particles from sediments
  • Geochemical behaviour of volatile elements (noble gases, halogens) during subduction (e.g. high pressure assemblages Syros)
• Cosmochemistry, astromineralogy, meteorites and the early solar system
  • Origin of the solar system, formation of planetary bodies
  • Cooling history and structure of meteorite parent bodies, ⁴⁰Ar/³⁹Ar dating and ²⁴⁴Pu fission tracks in ordinary chondrites (ABC news, Spektrum direkt, 3sat nano, space.com)
  • Planetary collisions and large meteorite impacts on Earth (see public outreach)
  • Meteorites from Mars and the Moon
  • Dust metamorphism, growth and planet formation in protoplanetary disks
  • Collection and analyses of cosmic dust (e.g. STARDUST mission, CosmicDustAnalyzer on CASSINI, COSIMA on ESA cometary mission ROSETTA)
  • Infrared spectroscopy and evolution of cosmic dust
• Isotopic dating (e.g. ⁴⁰Ar/³⁹Ar, K-Ca, U-Pb/Pb, I-Xe, Mn-Cr)
  • Dating of metamorphic and intrusive rocks, and volcanics
  • Dating of meteorites and impact craters, and associated tektites
  • Dating of metasomatic events in the subcontinental lithospheric mantle (e.g. cratonic mantle South Africa)
• Methodology
  • Cl, Br and I detection via neutron induced noble gas isotopes ³⁸Ar, ⁸⁰Kr, ⁸²Kr und ¹²⁸Xe
  • Revision of the K decay constants for K-Ar and ⁴⁰Ar/³⁹Ar-dating
  • Calibration of age and neutron fluence monitors for ⁴⁰Ar/³⁹Ar dating
  • Surface exposure dating using cosmogenic nuclides
  • Instrumental development for in situ radiometric dating of planetary surfaces