Download Ore-forming magmatic-hydrothermal systems

PhD research in Switzerland:
Ore-forming
magmatic-hydrothermal systems
The Fluids and Mineral Deposits Group at ETH Zürich (Switzerland) investigates the interaction of geological
processes underlying hydrothermal heat and mass transfer in the Earth’s crust, including the formation of economic
mineral deposits. The practical aim is to advance our ability of predicting the location and composition of still
undiscovered resources, with an emphasis on the long-term development of new observational techniques and
modeling approaches. Up to three new PhD projects are expected to start in 2007, involving combinations of
geological field work, laboratory development and application of fluid inclusions microanalysis and isotope
geochemistry, and hydrodynamic modelling of Cu-Au-mineralising magmatic-hydrothermal systems.
The PhD projects will be funded for 3–4 years by the Swiss National Science foundation, are partly supported by
the international minerals industry, and will have access to the full range of educational and laboratory facilities of
ETH’s Department of Earth Sciences. Applicants should have an MSc or an equivalent 4-5 year science degree in
the broader field of the earth sciences. Please http://proto-igmr.ethz.ch/ for further information about our group and
related publications, and apply with your CV and a statement of your professional interests by e-mail to
[email protected]. Projects can start any time after April 2007, once funding is confirmed.
Sulphur analysis in fluid inclusions: link between porphyry and epithermal ore deposits
Our lab has pioneered the development of LA-ICP-MS for fluid and melt inclusion
analysis. The ability to analyse ore-metal concentrations in ancient fluids has led to the
discovery that low-density magmatic vapor is a major ore-forming fluid in zoned
porphyry copper and epithermal gold deposits. Besides the ore metals, sulphur is
arguably the most critical chemical element in hydrothermal ore formation. Taking
Bajo de la Alumbrera (Argentina) and Bingham (USA) as field examples, this project
will develop and use metal and sulphur microanalysis by a combination of new LAICP-MS techniqus. Fluid studies will be applied to identify the likely gold-transporting
fluid channelways linking porphyry copper and epithermal gold deposits in magmatic hydrothermal systems. The
project offers an opportunity for developing and applying innovative geochemical techniques, combined with own
field work to decipher complex ore-forming hydrothermal processes.
An integrated hydrodynamic process model for the Bingham porphyry-Cu-Mo-Au system
The fluid flow structure and evolving temperature distribution in magmatic-hydrothermal
systems control the location and degree of metal enrichment in major ore deposits, but is
also relevant to the understanding of eruption mechanisms in arc volcanoes. To investigate
and predict the ‘hydrology’ of ore-forming magma chambers and overlying volcanoes, we
have developed a finite-element code for simulating two-phase fluid flow (saline liquid +
vapour ± groundwater) across the entire range from magmatic to surface conditions and
from pure water to hydrous salt melts (see density plot left). Modeling capabilities are now
ready to be linked with extensive observational data for the giant Bingham porphyry-CuMo-Au deposit, being studied by several current and new graduate students (above). This
new project will build the first fully-integrated process simulation model of a specific ore-forming magmatichydrothermal system, eventually leading to scenario-testing for the exploration of other porphyry-epithermal ore
systems. The new PhD student should bring along some experience in one, and be keen to learn the other, of two
essential research components that will be linked in this project: (a) obtaining a 3-D understanding of a complex
geological data set, to be compiled in collaboration with company geoscientists at Bingham and including some
own field work; and (b) the application and minor suppplementary programming of a high-level computer code,
using top-end single- and parallel-processing hardware.
Geodynamics and geochronology of the Balkan – Carpathian Cu-Au ore province
Within the European GEODE program, we have over the last years established
collaborative links with Bulgarian and Romanian partners, to explore the relationships
between lithosphere-scale geodynamics and ore formation in South-Eastern Europe. A
new PhD project will extend our research into the emplacement history and
geochemistry of Upper Cretaceous magmas and related porphyry-type and epithermal
Cu and Au deposits to Western Bulgaria and the economically important Timok Zone
of Serbia. The ideal PhD students for this project will combine an interest in regional
tectonics and metallogeny, including extensive own field work in collaboration with
local geoscientists, with an interest to learn and further advance state-of-the art laboratory techniques for highprecision geochronlogy and new isotopic tracing techniques, which may be applicable to large-scale regional
mineral exploration worldwide.