Pressure-Temperature-Time lab

The Pressure-Temperature-Time (P-T-t) lab at NIU facilitates studies involving metamorphic pressures, temperatures, and time.

Experimental studies at elevated pressures and temperatures are carried out to understand mineral behavior and properties, as well as to test analytical methods in petrology and mineralogy. In-situ experimental studies are carried out to understand mineral changes at elevated pressures and temperatures. Mineral synthesis experiments are used to test petrologic analytical methods as well as to synthesize materials for in-situ experiments.

Observational studies investigate ancient rocks to constrain metamorphic pressures and temperatures, as well as the timing of metamorphic events. Geochronology studies are combined with P-T modeling (including elastic and thermodynamic geothermobarometery) and field work to reconstruct P-T-t paths for metamorphic rocks. Studies into the P-T-t geologic histories of rocks are carried out to understand metamorphic and tectonic processes.

Research

• High PT experimentation

• Experimental mineral synthesis

• U-(Th)-Pb Geochronology

• Geothermobarometry

• Thermodynamic P-T modeling (Pseudosection and thermobarometry)

• Elastic modeling (QuiG geobarometry)

• Structural thermometry (Raman Spectroscopy of carbonaceous material)

Lab Equipment

• Rockland Research Corporation Piston Cylinder
  • Boyd and England style device
  • Used for mineral synthesis at elevated P-T up to 35 kbar and 2000 °C
• Diamond Anvil Cells
  • 1 Inconel 718 diamond anvil cell
  • 1 HPDO diamond anvil cell
  • Used for high pressure experimentation up to 20 GPa
• Lecia DM2700P Petrographic Microscope
  • Used for petrography and microstructural analysis
• Lecia Investa Binocular Microscope
  • Used for picking mineral grains for geochronology, loading experimental DAC devices, and producing full thin section maps for petrography and dating
• Field Equipment
  • Sampling hammers, chisels, solar charger, field-capable tablet with Strabospot and FieldmoveClino, brunton compass, and camping equipment
  • Used for sample collection and geologic mapping

Additional capabilities through collaborations with other NIU laboratories

• Laser ablation inductively coupled mass spectrometer (LA-ICP-MS)
  • For U-(Th)-Pb monazite, zircon, and titanite geochronology
• X-ray fluorescence
  • For determination of bulk composition used in thermodynamic P-T modeling
• Scanning electron microscopy
  • For imaging sections for LA-ICP-MS analysis, identifying minerals, and analyzing experimental products
• Grain mount and thin section preparation equipment
  • Tile saws, diamond powders, epoxy mounts, epoxy, and microscopes
  • For preparing samples for petrography, microstructural analysis, experimentation, and geochronology
• Rock crushing equipment
  • Saws, rock crushers, and a shatterbox
  • For powdering samples for bulk composition analysis and preparing samples for experimentation