Department of Mineralogy

 

Note: Cette page est une version d'archive. Voir les informations actuelles ici:
Sciences de la Terre et de l'Environnement.
Note: This is an archive version. Current information can be found here:
Earth and Environmental Sciences.

Research concentrations

The research programs of the Department are divided into the five general domains of Magmatism and Volcanology, Physical Volcanology, Isotope Geochemistry and Geochronology, Geological Risk (CERG), and Ore Deposit Genesis, which are respectively the responsibilities of Professors M. Dungan, U. Schaltegger, C. Bonadonna, and L. Fontboté, in collaboration with academic staff members members D. Fontignie, R. Moritz, S. Th. Schmidt, M. Chiaradia, R. Spikings and C. Frischknecht, postdoctoral assistants (K. Kouzmanov, L. Pioli, I. Marton, I. Manzella, M. Ovtcharova), and 20 PhD students. Many of the research involve multiple international collaborators and all involve PhD and MSc students.

Click here for publications resulting from these programs.
Click here for teaching information and for analytical resources.

A. Magmatism and volcanology

The primary focus of the group led by Prof. M. Dungan is continental arc magmatism, with a special emphasis on understanding intra-crustal open-system magma differentiation. Our approach to these questions is to comprehensively integrate field relations, volcanic stratigraphy, geochronology, and paleomagnetic constraints to develop a rigorous geologic context for all subsequent geochemical and petrologic studies, and then to combine data from whole-rock major element, trace element, and isotope chemistry, petrography, and mineral chemistry to arrive at models for the short-term and long-term magmatic evolution of the volcanic centers of interest.

Following the completion of several studies in the San Juan volcanic field, in collaboration with Peter Lipman (Ph.D. theses of Olivier Bachmann & Fleurice Parat), we have turned our attention entirely to investigations of frontal arc volcanic centers of the Andean Southern Volcanic Zone. Our research efforts have been divided among; (1) A long term study of the Quaternary Tatara-San Pedro complex (TSPC, 36°S, Chilean Andes; 1984-present). The Ph.D. thesis of Fidel Costa was one expression of this project. (2) A study of the nearby volcanic center that lies across the segment boundary to the south of the TSPC (Nevado de Longaví; 36.2° S; Ph.D. theses of Daniel Sellés and Carolina Rodríguez during 2001-2006), and (3) Our recently initiated investigation of Volcán Llaima on which Caroline Bouvet de Maisonneuve is undertaking a Ph.D. thesis.

B. Physical Volcanology

The physical volcanology group led by Prof. C. Bonadonna is focused on field, numerical and experimental investigations of volcanic processes. In particular, we are interested in the understanding of explosive volcanism and in the probabilistic assessment of associated hazards. As part of this group, a state-of-the-art sedimentology lab for characterizing volcanic particles and a fluid dynamics lab for detailed studies of volcanic processes have just been completed.

National and international collaborators include: Dr. JC Phillips (University of Bristol, UK), Prof. B. Chopard (University of Geneva, Switzerland), Prof. P. Haas from l’Ecole d'ingénieurs de Genève (CMEFE - Groupe de compétences en mécanique des fluides et procédés énergétiques / IMEC), Prof. B. Azzopardi (University of Nottingham, UK), Prof. M. Rosi (Pisa University, Italy), Prof. R. Cioni (Cagliari University, Italy), Prof. M. Ripepe (Florence University, Italy), Dr Armann Hoskuldsson (University of Iceland, Iceland), Prof. CB Connor (University of South Florida, USA), Prof. BF Houghton (University of Hawaii, USA), Prof. CE Gregg (East Tennessee State University, USA), Dr. A. Costa (INGV Napoli, Italy), Dr. S. Scollo (INGV Catania, Italy) and Dr. J. Clavero (Energia Andina, Chile). For research projects and facility details please visit: http://www.unige.ch/sciences/terre/mineral/volcano/index_en.html

C. Isotope geochemistry and geochronology

The research group in isotope geochemistry and geochronology is directed by Prof. Urs Schaltegger, together with research collaborators Dr. D. Fontignie, Dr. Massimo Chiaradia and Dr. Richard Spikings. The group includes post-doc research fellows and PhD students. The technical infrastructure features metal-free clean-air laboratories, two thermal ionization mass spectrometers, a Finnigan MAT262 and a Thermo-Fisher TRITON, a 40Ar/39Ar dating laboratory equipped with an ARGUS gas mass spectrometer from Thermo-Fisher and a Noblesse from NuInstruments, and a fission track dating laboratory.

The isotope group follows a variety of research directions: (1) High-precision U-Pb geochronology using mainly zircon, but also monazite, xenotime, titanite and other minerals. (2) Sr, Nd, Pb, Hf tracing and dating of magmatic, metamorphic and ore-forming processes, and of climate change. (3) Regional geochronological projects study of duration and rates of magmatic and tectonic processes, including terrane and provenance studies using detrital zircon. (4) Determining the thermal evolution of accreted and autochthonous terranes along the South-American continental margin using Ar-Ar, fission-track and U-Th/He dating. The laboratory hosts Master and PhD students, as well as post-doctoral researches from the Mineralogy and Geology Departments of Geneva and Lausanne Universities, as well as visiting scientists from other Swiss and foreign universities.

Current projects include:

  • Quantification of post-extinction biotic recovery after the Permian/Triassic and Triassic/Jurassic mass extinctions, c. 250 and 200 Ma ago, as well as of the Toarcian anoxic crisis, c. 180 Ma ago. Ultraprecise and accurate U-Pb age determinations on zircon from volcanic ash beds from within well-documented and ammonoid-/conodont-calibrated marine cross-sections in China, Peru, USA and New Zealand are compared to data on basalt flows from the Central Atlantic Magmatic Province and the Karoo continental basalt province, in order to assess their role in triggering global climate change and mass extinction.
  • Evolution of the pre-Andean Gondwana margin in Peru: tectonic evolution of the Proto-Andean continental margin from Carboniferous extension and Triassic rifting to Jurassic arc magmatism and subduction.
  • Precise and accurate ID-TIMS dating of standard zircon for laser ablation ICP-MS U-Pb dating using an Excimer ArF laser and an ELEMENT2 XR at University of Lausanne. In collaboration with Prof. O. Müntener and Dr. F. Bussy, University of Lausanne.
  • Late Tertiary transition from calc-alkaline to adakite-like magmatism in Ecuador and its bearing on the formation of porphyry-related deposits: U-Pb dating and Pb-Sr-Nd isotope systematics of magmatic rocks.
  • Resolving magma chamber processes, tracing magma mingling, crystallization, fractionation and initial cooling of the Adamello batholith in NW Italy, by high-precision and laser-ablation ICP-MS U-Pb dating using zircon and titanite, isotopic tracing and geochemistry. Joint ProDoc program with ETH Zürich and University of Lausanne
  • Intercalibration of astronomical with isotopic (Ar-Ar and U-Pb) timescales by U-Pb zircon dating of volcanic ash beds in Miocene cyclic sedimentary successions of the Mediterranean.
  • Investigating the origin of the Interandean Depression, Ecuador, in order to understand the response of the bounding cordilleras to the formation of an intermontane, ramp basin. This project includes: i) U/Th-He analysis of apatite from the Ecuadorian Cordilleras with Dr. Peter Crowhurst, CSIRO, Sydney. ii) The production of a high resolution, 40Ar/39Ar based chronostratigraphy for sedimentary basins within the Interandean Depression.
  • Geochemical, Geochronological and Petrological Characteristics of the Ophiolitic Rocks located between the Central Anatolian Crystalline Massif and the Pontide Belt, in collaboration with Prof. F. Çelik (Kocaeli University, Turkey) and Prof. R. Marschik (Ludwig-Maximilians University, Munich, Germany).

For more information on people, projects and equipment, see:
http://www.unige.ch/sciences/terre/mineral/isotopes/min_isotopes.html

D. Geological Risk (CERG)

The CERG (Certificat de formation approfondie en Etude et management des Risques Géologiques) provides a comprehensive training in management of geological risk. It consists of five modules (risk management, seismic hazard, volcanic hazard, terrain instabilities and hydro-meteorological hazards) and is run every summer (April-June). Over the last 20 years the CERG has trained participants from 65 countries around the world in collaboration with the Swiss Federal Institute of Technology (EPFL) and in association with the United Nations University (UNU), the Swiss Agency for Development and Cooperation (SDC) and the International Strategy for Disaster Reduction (ISDR). It has also cooperated in research projects around the world. More details can be found at: http://www.unige.ch/sciences/terre/mineral/CERG/index.html

E. Ore deposits

Circulation of fluids is the principal control on the formation of hydrothermal base metal and gold deposits at different levels of the continental crust. The general aim of the Geneva Ore Deposits Group led by Lluís Fontboté and Robert Moritz, in collaboration with Kalin Kouzmanov and Massimo Chiaradia, post docs and graduate students, is to investigate the geochemistry and role of fluids in the formation of ore deposits. Several projects are carried out in close cooperation with mining companies. Main current projects, most including at least one PhD or MSc project are the following.

Other pages of this web site give information concerning the publications on line, teaching programs and internet resources related to ore deposits research.

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