Areas of Interest :
Igneous Petrology and Volcanology of large silicic systems.

Research Groups :
Petrology/Mineralogy/Geochemistry
Volcanology

Education :
Ph.D., Volcanology-Petrology-Geochronology, University of Geneva, 2000
M.S., Earth Sciences, University of Geneva, 1997

Current Research Interests :
My main research interests are in physical volcanology and igneous petrology of evolved magmatic systems. I am particularly fascinated by large caldera-forming events (now commonly referred to as “Supervolcanoes” since a popular BBC/Discovery Channel dramatization introduced the term to the general public – and to the scientific community). I have used many different techniques to address issues related to the eruptive dynamics and magmatic evolution (both rates and processes) of these giant eruptions and like to integrate data from geochemistry and geophysics to develop models that are consistent with both realms.

Presently, my students and I are working on projects in several magmatic provinces around the world, including the South Aegean Arc (Greece), the Southern Volcanic Zone (Chile) and the San Juan Volcanic Field (Colorado). All these projects involve a fair share of field work, but also require the use of sophisticated geochemical and modeling tools (at the University of Washington and elsewhere).

Graduate Students (at the University of Geneva) :
 

Selected Publications :

Bachmann, O., Miller, C.F., de Silva, S.L. The volcanic-plutonic connection as a stage for understanding crustal magmatism, Journal of Volcanology and geothermal Research (2007). In press

Charlier, B. L. A., Bachmann, O., Davidson, J. P., Dungan, M. A., and Morgan, D. J.: The Upper Crustal Evolution of a Large Silicic Magma Body: Evidence from Crystal-scale Rb–Sr Isotopic Heterogeneities in the Fish Canyon Magmatic System, Colorado, Journal of Petrology Advance Access published on August 20, 2007, DOI 10.1093/petrology/egm043.

Bachmann, O., Charlier, B.L.A., and Lowenstern, J.B., 2007, Zircon crystallization and recycling in the magma chamber of the rhyolitic Kos Plateau Tuff (Aegean Arc): Geology.

Bachmann, O., Oberli, F., Dungan, M.A., Meier, M., and Fischer H. (2007): ⁴⁰Ar/39Ar and U-Pb dating of the Fish Canyon magmatic system, San Juan Volcanic field, Colorado: evidence for an extended crystallization history. Chemical Geology

Bachmann, O., and Bergantz, G.W. (2006): Gas percolation in upper-crustal magma bodies as a mechanism for upward heat advection and rejuvenation of silicic crystal mushes. Journal of Volcanology and Geothermal Research, vol 149, p. 85-102.

Bachmann, O., and Bergantz, G.W., (2004): On the origin of crystal-poor rhyolites: extracted from batholithic crystal mushes, Journal of Petrology 45 (8), 1565-1582.

Bachmann, O., and Bergantz, G.W., (2003): Rejuvenation of the Fish Canyon magma body: a window into the evolution of large-volume silicic magma systems, Geology, v. 31, no.9, p.789-792.

Bachmann, O., Dungan, M.A., and Lipman, P.W., (2002): The Fish Canyon magma body, San Juan volcanic field, Colorado: rejuvenation and eruption of an upper-crustal batholith. Journal of Petrology 43 (8), p.1469-1503.

Bachmann, O., Dungan, M.A., and Lipman, P.W., (2000): The Pagosa Peak Dacite, San Juan volcanic field, Colorado: Voluminous low-energy eruption prior to a major ash-flow eruption. Journal of Volcanology and Geothermal Research 98, p.153-171.

Full CV Link :