Magmatic and Ore-Forming Processes Research Laboratory

Research

 

Focus of research

Our research focuses on the mass transfer of volatile and economically important metallic elements in magmas and high-pressure-temperature fluids with special attention to the genesis of magmatic-hydrothermal ore deposits (e.g. porphyry, epithermal and skarn mineralizations). We combine experimental and field-based studies to deepen our understanding of the above processes.

 

Current areas of research

 

Some of our methods

Synthetic fluid inclusions

High-pressure-temperature fluids are sampled during the experiment in the form of microscopic-sized fluid droplets enclosed in quartz. These form by the healing of fluid filled fractures in the quartz, which are generated by thermal shock during the experiment after equilibrium between the various fluid and solid phases have been achieved. These fluid inclusions later can be analyzed by LA-ICPMS, Raman and FTIR spectroscopy. Solubility studies are complemented by in-situ spectroscopic investigation and computational chemistry calculations to determine the speciation of volatile and metallic elements.

SFI

Synthetic vapor-type fluid inclusions formed in an experiment at P=150 MPa and T=1000 oC.

Predicted geometry of a KAu(HS)2 complex using static computational chemistry calculation.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Classical phase equilibrium experiments

Various phases are equilibrated with each other in noble metal capsules using high P-T experimental apparatus (e.g. cold seal pressure vessel and piston cylinder apparatus). Run product compositions are determined by various in situ analytical methods including Electron Probe Microanalysis, LA-ICPMS and FTIR.

Apatite and magnetite crystals in a dacite glass from a phase equilibrium experiment at 900 oC and 200 MPa. Sulfur and halogen concentrations in apatite carry information on the volatile budget of the magma.

Fluid and melt inclusions in natural systems

Fluid, silicate melt and sulfide inclusions trapped in minerals record the composition of the silicate melt, sulfide mineral/melt and hydrothermal fluid phases in natural ore-forming systems. By analyzing such inclusions we can determine the temporal and spatial evolution of the concentration of metallic and volatile elements essential for ore-formation and, therefore, identify the most critical processes distinguishing barren and fertile systems.

FI

Coexisting vapor-type fluid and silicate melt inclusions (SMI) in quartz from a miarolitic cavity sample from Mt. Malosa, Malawi. Such inclusion assemblages can be used to determine volatile/melt partition coefficients for a large number of elements simultaneously.

MI

A silicate melt inclusion in clinopyroxene from volcanic rocks associated with the Gaosongshan epithermal gold deposit in China. Such inclusions carry information about the ore metal and volatile budget of magmas.