PhD Project
Controls of clay mineral and gold distribution
at Cerro Corona, Peru
Dr. Jamie Wilkinson & Dr. Andrew Wurst (Goldfields Exploration Inc.)
AIM To develop a predictive model for the distribution of clay minerals and gold mineralization at the Cerro Corona
porphyry copper-gold mine, Peru, that will help to optimise mining and processing efficiency for the life of mine.
BACKGROUND Porphyry deposits, formed in association with igneous rocks, are major sources of the world’s
copper, gold and molybdenum. Clay minerals are a common alteration product in these systems and although
conventional geological models describe the general distribution of clays, in detail these zones are complex and highly
varied. The distribution and character of clays is particularly important when they occur in ore zones because they
impact directly on the efficiency of mineral processing. Optimising mill efficiency by understanding clay distributions
and chemistry can reduce energy use and carbon footprint.
OBJECTIVES The principal objective is to map the distribution of clay minerals and host rock lithologies at Cerro
Corona using field observations and portable infra-red spectroscopy and constrain the underlying geological controls
of alteration style and distribution. A secondary objective is
to determine the distribution of gold in the deposit to
optimise mining efficiency and resolve reconciliation issues.
It is suspected that low temperature epithermal veins play
an important role. Here, the underlying scientific question
is how the cool hydrothermal fluids responsible for these
veins relate to the high temperature porphyry stage.
Although porphyry-epithermal transitions are documented
in many systems and theoretical models exist for fluid
evolution pathways and copper-gold transport, these have
yet to be rigorously tested.
METHODS The study will utilise field mapping and infra-red spectroscopy in the open pit at Cerro Corona, coupled
with drillcore logging and sampling. Wholerock geochemistry will be determined carried using ICP-AES and ICPMS
instruments, clay mineralogy will be refined using X-Ray diffraction, and copper isotope measurements to track
vapour transport pathways will be made using the Department’s Nu Plasma multi-collector ICPMS located in the Royal
School of Mines Building. Vein petrography and fluid inclusion microthermometry will be carried out in the Fluid
Inclusion and Research Microscopy Laboratory at Imperial and using beam instruments at the Natural History
Museum.
WIDER IMPLICATIONS The research will produce outcomes that will be more widely applicable in large tonnage,
low grade porphyry deposits, in particular the potential reuse of clay for tailings dam construction, understanding of
the porphyry-epithermal transition and fractionation of copper isotopes.
STUDENT PROFILE We are looking for a well-qualified and highly motivated Earth Sciences/Geology graduate with a
strong interest in mineralogy, geochemistry and ore deposits. Experience of geochemical analytical methods would be
an advantage.
TRAINING The successful student will join the LODE research group in ore deposits at Imperial College and the
Natural History Museum. The student will receive training in relevant research and transferable skills from the CASE
supervisor, company staff on site in Peru, the academic supervisors at Imperial College and by attendance at internal
and external taught courses and workshops (including the SEG porphyry mapping course, run annually in Nevada,
USA). In addition, the student will benefit from the in-house expertise in socio-economic and environmental impacts
of mining within the CASE partner organization. The student will also be trained in analytical techniques, including
portable infra-red spectroscopy and copper isotope analysis, and a range of courses in isotope geochemistry, fluid
geochemistry and mineralising processes and transferable skills will be available. The project will provide a great
opportunity to work in a major modern open pit copper-gold mine in collaboration with a leading mining and
exploration company that pioneers socially and environmentally responsible mining.
FURTHER INFORMATION If you are interested in the project and would like to have further details please contact
Jamie Wilkinson at j.wilkinson@imperial.ac.uk