PhD research position in Economic Geology
PhD research position in Economic Geology
University of Geneva (Switzerland)
Tracing fluid evolution in the Miocene polymetallic Cordilleran deposits
of Colquijirca and Cerro de Pasco, central Peru
Applications are invited for a fully funded Ph.D. research position in Economic Geology to commence in June
2012. The project aims to trace the fluid evolution of magmatic-hydrothermal systems at Cerro de Pasco and
Colquijirca - two major Cordilleran deposits in the Miocene polymetallic belt of central Peru. It is mainly
sponsored by the Swiss National Science Foundation and will be coordinated with the Vólcan Companía
Minera S.A. and the Sociedad Minera El Brocal S.A.A. operating in the studied areas.
Cordilleran or “Butte type” polymetallic mineralization occurs as veins, massive replacement bodies, and
sulfide-cemented breccia bodies in the upper parts of porphyry systems. Most of it is largely epithermal,
overprinting earlier veins with potassic and phyllic alteration assemblages. A fluid inclusion study of
Cordilleran mineralization at Morococha
(Catchpole et al., 2011) demonstrated
that mineralizing fluids in polymetallic
veins directly overprinting barren and
mineralized porphyry systems have
dominantly magmatic signatures and
compositions similar to the fluids
forming porphyry mineralization at
depth. In contrast, fluids forming
Cordilleran deposits in volcanic setting (e.g., Cerro de Pasco and Colquijirca) have also magmatic signatures
but are highly diluted by meteoric waters, as evidenced by stable isotope analyses of gangue minerals. Recent
studies on the geological setting, mineralization and alteration assemblages, metal and mineral zonation, stable
and radiogenic isotope geochemistry and geochronology of the Cerro de Pasco and Colquijirca deposits
(Baumgartner et al., 2008, 2009 Bendezú et al, 2003, 2008, 2009) provide detailed background information
that will serve as a basis for the comprehensive fluid geochemistry research project.
The principle objective of the project is to determine intensive parameters (P-T), composition and stable and
radiogenic isotope signatures of mineralizing fluids, to test the existing models for the origin of fluids, solutes
and metals in magmatic-driven Cordilleran polymetallic hydrothermal systems, studying Cerro de Pasco and
Colquijirca as examples.
Methodology and training
Fluid inclusions preserving microsamples of hydrothermal fluids that formed the Cordilleran mineralization at
Cerro de Pasco and Colquijirca can be found in transparent gangue (quartz, carbonates) and opaque ore
minerals (enargite, sphalerite, and pyrite). These can be analyzed by visible and near-infrared light microscopy
and microthermometry. Laser ablation ICP-MS technique can be applied to accurately determine minor and
trace element (including S and metals) composition, as well as Cl and Br isotopes in single fluid inclusions.
Stable isotopes (O, H, C) and noble gas geochemistry will be applied to trace the origin of fluids. A
combination of Sr and Pb isotope determinations in inclusion fluids will be used to trace fluid-rock interactions
along pathways of the hydrothermal fluids and possible contribution from different host-rocks.
The successful candidate will join a very active Ore deposits group at University of Geneva and will receive
training in large spectrum of analytical methods. The project will involve collaboration with other institutions
including the ETH Zurich and the University of Lausanne.
View of the open pit at the Cerro de Pasco deposit, central Peru
Applications are welcome from well-qualified and highly motivated graduates with education in Geology,
Geochemistry, Earth Sciences or related fields with a strong interest in geochemistry and hydrothermal ore
deposits. Research in this project involves fieldwork in Peru at high altitude (over 4’000 m) and extensive
analytical work. Analytical skills in fluid inclusion analyses, isotope geochemistry, and different microscopic
and spectroscopic analytical methods, will be considered as an advance.
The PhD project is fully funded for 3 years, with a possibility of 1 year extension. Interested applicants are
requested to send a CV (including details on all third level university courses and grades), with covering letter,
two references, (expected) date and abstract of MSc thesis and full contact details. Applications should be sent
as a single PDF file by email (see below). Deadline is 15th April 2012.
Contact and further details
Dr. Kalin Kouzmanov (firstname.lastname@example.org, +41 22 379 6893 or 6624)
Prof. Lluís Fontboté (email@example.com, +41 22 379 6622 or 6624)
Department of Mineralogy
Earth and Environmental Sciences
University of Geneva
Rue des Maraî chers 13
Tel: +41 22 379 66 24
Fax: + 41 22 379 32 10
Recent relevant publications
Baumgartner, R., Fontboté, L., Vennemann, T. (2008) Mineral zoning and geochemistry of epithermal polymetallic Zn-Pb-
Ag-Cu-Bi mineralization at Cerro de Pasco, Peru. Economic Geology, 103: 493-537.
Baumgartner, R., Fontboté, L., Spikings, R., Ovtcharova, M., Schaltegger, U., Schneider, J., Page, L., Gutjahr, M. (2009)
Bracketing the age of magmatic-hydrothermal activity at the Cerro de Pasco epithermal polymetallic deposit, central
Peru: a U-Pb and 40Ar/39Ar Study. Economic Geology, 104: 479-504.
Bendezú, R., Fontboté, L., and Cosca, M. (2003) Relative age of Cordilleran base metal lode and replacement deposits and
high sulfidation Au-(Ag) epithermal mineralization in the Colquijirca mining district, central Peru. Mineralium
Deposita, 38: 683—694.
Bendezú, R., Page, L., Spikings, R., Pecskay, Z., Fontboté, L. (2008) New 40Ar/39Ar alunite ages from the Colquijirca
District, Peru. Evidence of long period of magmatic SO2 degassing during formation of epithermal Au-Ag and
Cordilleran polymetallic ores. Mineralium Deposita, 43: 777-789.
Bendezú, R., Fontboté, L. (2009) Cordilleran epithermal Cu-Zn-Pb-(Au-Ag) mineralization in the Colquijirca district,
central Peru: Deposit-scale mineralogical patterns. Economic Geology, 104: 905-944.
Catchpole, H., Kouzmanov, K., Fontboté, L., Guillong, M., Heinrich, C.A. (2011) Fluid evolution in zoned Cordilleran
polymetallic veins – Insights from microthermometry and LA-ICP-MS of fluid inclusions. – Chemical Geology, 281:
消息来源 I-Ming Chou
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