Spring 2020 call for proposal cancelled

Dear all,

As you may already know, the SwissSIMS lab is closed, as UNIL, until at least April 30th. The SwissSIMS schedule, originally full until late August, will thus have to be reorganized as soon as we will now when the labs could re-open. It is yet not clear when the SwissSIMS lab will reopen, but we would like to specify 2 points:

  • We will first have to perform some tests, to ensure the machine is still working well after 7 weeks (or more) of shutdown
  • Social distancing in our lab is hard to maintain. Late March, we were supposed to do maintenance to fix a problem affecting the measurements in Cs mode. We will have to do this maintenance before any Cs mode measurements. And this maintenance requires the presence of 2 persons. So we might be able to run only in “hyperion” mode during the first weeks of reopening, with only one person in the lab (ie, only experienced used).

For those reasons, we decided to cancel the first SwissSIMS call for proposal 2020. The persons originally scheduled until late August will be/have already been contacted and will be kept updated on the schedule. We will discuss with them the different possibilities for their session (report later, or send us the mounts + documentation, or other options)

In the meantime, please let us know if there is any “urgent” project that should be done by the end of this year (or even before, for the PhD students finishing their thesis). We’ll do a priority list and rework the schedule as best as we can.

We apologize for the inconvenience

 

Best wishes,

The SwissSIMS team

SwissSIMS closed

Due to Covid-19, the SwissSIMS lab (as UNIL) is closed until April 30th. This might of course last longer, depending on the evolution of the situation.

We will contact all person that were already scheduled until July, so find new dates.

Open positions

There are 2 PhD and one post-doctoral position available at the University of Lausanne, funded
by a Swiss National Science foundation. The goal is to develop quantitative models of crystal
growth in metamorphic and igneous systems. Top of the line analytical methods (FEG-SEM,
FEG-EMPA, μC-Xray Tomography, SIMS, NanoSIMS) will be used to quantify zoning of
minerals and the zoning around minerals in experimental on porphyroblast growth of igneous
minerals and natural examples of metamorphic porphyroblasts. The amount of local
disequilibrium will be assessed, and quantitative 2 and potentially 3-D models for crystal
growth will be developed. It is expected that one PhD student will focus on the metamorphic
study, while the second PhD will focus on igneous and experimental studies. Finally, the
modelling study will be mostly achieved by the post-doctoral fellow, but PhD students are
expected to contribute to the modelling. More details can be found below.
Applications, including contacts for references and a short motivation statement should be sent
to Lukas Baumgartner (Lukas.baumgartner@nullunil.ch). Evaluation of dossiers will start by
October 14th, but applications will be accepted until filled.


Growth models for igneous and and metamorphic minerals: quartz and garnet

This project proposes to use continuum mechanics modelling to understand geochemical and textural aspects of igneous and hydrothermal vein quartz using diffusion-surface reaction models. In these environments, quartz is growing from oversaturated conditions into a structureless continuum. In a first study, I propose to experimentally grow quartz in a rhyolitic melt containing trace elements typical for rhyolite environments. Growth will be induced by changing the saturation of quartz in these melts by changes of water activity, pressure, and temperature in cold seal experiments. Water activity will be changed due to water loss induced by hydrogen gradients between the capsule and the pressure media. Temperature and pressure will be decreased monotonically and cycled to induce polybaric/thermal crystal growth. Rapid quenched capsules will be opened and cut after careful μC-X-ray tomography to locate quartz crystals. Melt halos will be analyzed using low voltage FG-EMPA for major and minor elements and SIMS for trace element composition gradients. SIMS analysis of water and selected cations (Na, Li, Al, H, P) will be performed in the quartz crystals using the newly acquired RF-Hyperion source on the SIMS and NanoSIMS. We will develop a multi element diffusion-reaction kinetics code using initially MATLAB, which will be translated for more complex simulations to graphic cards CPU optimized parallel code using a full Gibbs Free energy minimization.
The second project will explore the conditions under which rhythmically zoned hydrothermal quartz precipitates using the same model, exploring Al poisoning of the surface of quartz as a potential reason for it. Quartz growth in a hydrothermal solution will use the same numerical code, but thermodynamic data for ions and complexes, pH or Na+ as a growth accelerator and Al as a kinetic inhibitor instead. The results will be compared to natural samples of vein quartz. Preliminary work suggests that significant amounts of H+ is included in quartz along with Al3+ to compensate the Si4+ ion in quartz. We will attempt to use the fact that boron isotope fractionation between tourmaline and fluid is strongly pH dependent to see if we can correlate tourmaline isotope composition included in quartz with Al-H zoning of these quartzes.
The final project will explore how far this modelling approach can be used to explain zoning and texture (for example porphyritic) of garnet growth in regional and contact metamorphic environments. To this end we will modify the growth model to include surface kinetic equations for each matrix mineral, modal abundances of the minerals, and a continuum approach to the grain boundary structure. We will attempt to model the zoning of contact metamorphic garnets from the Little Cottonwood stock (Utah, USA) using thermal models. P-T conditions will be monitored using QUIG and Raman in graphite. We will compare our free energy minimization
coupled reaction-diffusion approach with the recently developed effective bulk composition approach (Spear and Wolfe, 2018). In contrast, we expect that the solubility of elements will significantly influence garnet zoning through the development of local depletion and enrichement zones surrounding garnet. Changing surface reaction kinetics for matrix minerals will allow us to approach models which are assuming local equilibrium and Gibbs Duhem relations.

Installation of Hyperion RF Plasma source (05.04.2019)

The installation of the new Hyperion II RF Plasma source has started this week. This source will be used to create dense and stable O- or O2- primary ion beam. It replaces the “classical” duoplasmatron source.

The denser primary beam created will allow doing small spot analysis, with similar – even higher – secondary count rates on the selected elements to be analyzed. The largely improved stability and source lifetime are also major benefits for the analytical sessions.

Installation, made by CAMECA, is scheduled to be done by April 19th, followed by several weeks of development and tests.

 

SwissSIMS workshop – UNIL – June 6th

Where: Geopolis building, room 1628 (ground floor)

 

Scientific program

9:15 – 9:30                Welcome coffee

9:30 – 9:40                Introduction

9:40 – 10:00              Carolin Fichtner (ETHZ) 

The origin and inventory of Earth’s carbon content as revealed by SIMS

10:00 – 10:20            Joshua Davis (UNIGE)

Investigating crustal contamination as a source of volatiles for CAMP magmatism: a zircon perspective

10:20 – 10:40            Juliana Troch (ETHZ)

The dark side of zircon: Evidence for fluid saturation in the subvolcanic reservoir of the Mount Jackson-Island Park Rhyolite series in Yellowstone (USA)

10:40 – 11:00            Coffee break

11:00 – 11:20            Emmanuelle Ricchi (UNIGE)

Age and crystallization duration of fissure monazite-(Ce): linking ion probe Th-U-Pb results with hydrothermal dissolution/precipitation events and deformation stages

11:20 – 11:40            Jonas Pape (UNIBE)

26Al-26Mg SIMS dating of chondrules: a window to the early solar system

11:40 – 12:00            Etienne Deloule (CRPG, Nancy)

Development of Sr isotopes measurements by SIMS

12:00 – 14:00            Lunch break

14:00 – 14:20            Alice Vho (UNIBE)

Garnet oxygen isotope analysis by SIMS: Matrix corrections and applications

14:20 – 14:40            Katharina Marger (UNIL)

Development of tourmaline reference material for in-situ isotope analyses by SIMS with application to Monte Rosa whiteschist

14:40 – 15:00            Matthieu Harlaux (UNIGE)

Tracing magmatic-hydrothermal transition processes at the world-class San Rafael tin deposit (Peru) by in situ oxygen isotope and trace element analyses of tourmaline

15:00 – 15:20            Coffee break

15:20 – 15:40            Florian Bulle (UNIBE)

SIMS oxygen isotope study of white mica in a complex magmatic-hydrothermal environment

15:40 – 16:00            Lukas Baumgartner (UNIL)

Tracing fluid flow and time scale in quartz using SIMS

16:00 – 16:20            Elias Bloch (UNIL)

Diffusion kinetic parameters of calcium in olivine retrieved via SIMS depth profiling

16:20 – 16:30            Conclusion

Open PhD position

Open PhD position in Geochemistry at Institute of Earth Sciences, University of Lausanne

 

We have an opening for a PhD student in the domain of chemical and physical processes affecting the composition recorded in melt inclusions in MORB and OIB. This work implies a large amount of secondary ion mass spectrometer (SIMS), and other in-situ techniques like FEG-EMPA, and LA-ICP-MS. The candidate is expected to develop and apply analytical protocols, and to interpret the data using spatial modelling.

This study is of particular importance as melt inclusions compositions are used to infer melting processes, conditions of melt extraction, degassing and mantle source chemical characterization. All post-entrapment processes have then to be considered to interpret the data.

Requirements

We seek a highly motivated candidate with keen interest in volcanic processes, and small scale processes. Analytical skills or a keen interest to learn them is required, as well as an interest to develop quantitative models. Experience with melt inclusions and/or SIMS is beneficial. Good English skills and ability to work independently are essential. A Master’s degree or equivalent in Earth Sciences at the time of the appointment is required.

Further particulars

The initial appointment will be for a period of 1 year. After satisfactory evaluation of the initial appointment can be extended to a maximum duration of 4 years. The position starts during fall 2018 and will be paid according to Swiss standards for PhD fellowships. University of Lausanne is committed to promoting gender equality.

 

Applications should include a letter of motivation, summary of MSc thesis work, CV and the names of three referees. All these documents, combined in one PDF file, should be sent to Anne-Sophie Bouvier (anne-sophie.bouvier@nullunil.ch). Review of applications will start May 15th. The position will remain open until filled.

new paper online (11.10.17)

Reconstruction of multiple P-T-t stages from retrogressed mafic rocks: Subduction versus collision in the Southern Brasília orogen (SE Brazil)

Tedeschi M., Lanari P., Pedrosa-Soares A., Rubatto D., Hermann J., Dussin I., Pinheiro M.A.P, Bouvier A.-S., Baumgartner L.P.

Lithos, https://doi.org/10.1016/j.lithos.2017.09.025

new paper online

“Weekly to monthly time scale of melt inclusion entrapment prior
to eruption recorded by phosphorus distribution in olivine from
mid-ocean ridges”

by M. Manzini, A.-S. Bouvier, L.P. Baumgartner, O. Müntener, E.F. Rose-Koga, P. Schiano, S. Escrig, A. Meibom, N. Shimizu,

Geology, doi:10.1130/G39463.1

6 Goldschmidt abstracts

Baumgartner L.P., Bégué F., Siron G., Luisier C., Marger K., Bouvier A.-S. (2017) Using Secondary Ion Mass Spectrometry to decipher fluid-rock interaction, Goldschmidt abstract 2017

Bloch E., Baumgartner L.P., Putlitz B., Bouvier A.-S. (2017), Late-stage fluid infiltration in the Zermatt-Saas ophiolite zone, Goldschmidt abstract 2017

Higashino F., Rubatto D., Kawakami T., Bouvier A.-S. (2017) Oxygen isotope zoning in garnet from granulite facies rocks, Goldschmidt abstract 2017

Luisier C., Baumgartner L.P., Bouvier A.-S., Siron G., Vaughan-Hammon J., Schmalholz S. (2017), Importance of relative water fugacity estimates in meta-granites and white schists from SIMS measurements of water content in phengite, Goldschmidt abstract 2017

O’ Farrell, D.J. Tomlinson E.L., Caufield J.T., Bouvier A.-S., Stuart F. M. (2017) Halogen Composition of the Proto-Iceland Plume Source Mantle, Goldschmidt abstract 2017

Siron G., Baumgartner L.P., Bodner R., Bouvier A.-S., Putlitz B. (2017), Chlorine content in biotite as tracer of fluid-rock interaction during contact metamorphism, Goldschmidt abstract 2017