Senior Bursary Award
7th Biennial Geo-SIMS workshop for Secondary Ion Mass Spectrometry at the
GeoForschungsZentrum Potsdam and following Goldschmidt Conference in Florence
Cees-Jan De Hoog, Edinburgh Ion Microprobe Facility & School of GeoSciences,
The University of Edinburgh
I would like to thank the Mineralogical Society for their support towards my attendance of
the 7th Biennial Geo-SIMS workshop for Secondary Ion Mass Spectrometry (SIMS, better
known as ionprobe amongst geoscientists) in Potsdam and the following Goldschmidt
Conference in Florence in August 2013.
The Biennial Geo-SIMS workshop was held at the GeoForschungsZentrum in Potsdam this
year in conjunction with the entry into service of their upgraded ionprobe facility
(installation of a new large geometry, high resolution Cameca IMS 1280). The facility is led by
Michael Wiedenbeck, who did a great effort in organising this three-day meeting and
securing many sponsors to keep the costs low. The workshop was attended by about 50
delegates, including staff from most Earth-science based ionprobe labs worldwide.
Ionprobe is mostly used for trace element and isotopic analysis at micron-scale resolution
and this was reflected in the various talks. However, there were various interesting other
presentations about 2D and 3D imaging at micrometer- down to nanoscale with ToF-SIMS,
NanoSIMS and Atom Probe Tomography. I gave a talk about water (as OH) in zircon and how
its contents are related to the amount of rare earth elements and phosphorus present.
Water contents are generally very low in zircons, but I and my co-workers found up to 1200
ppm H2O in REE-rich zircons in Fe-Ti gabbros from the Mid-Atlantic Ridge. This lead to an
interesting discussion at what water content zircon can be considered metamict, as some UPb dating labs use OH contents in zircon as a screening tool.
Group photo of the 7th Biennial Geo-SIMS workshop, August 2013 at GFZ in Potsdam.
Continued overleaf…
Following the workshop was the Goldschmidt Conference in Florence, with a Thursday
morning session “Modern Applications in Secondary Ion Mass Spectrometry” related to the
workshop. The keynote was by Martin Whitehouse, who made a strong case for the use of
ion imaging and ion tomography in zircon geochronology.
I presented a talk in the Monday afternoon session “ExTerra: Understanding subduction
through the study of exhumed terranes”. This was a very popular session with a wide range
of talks looking at the intricacies of subduction zone systems that can only be appreciated in
exhumed natural rocks. My presentation was about boron isotopes in olivines that formed
during dehydration of serpentine at high pressure and temperature in a fossil subduction
zone, now exposed in the Ligurian Alps in Italy. The olivines contained surprisingly high
boron contents as well as high boron isotope ratios. This indicates that during serpentinite
breakdown, not all boron was lost from the rock and that boron isotopes may be
fractionated. This is important for geochemists that look at the sources of fluids in
subduction zones, as boron is regarded a key tracer for the presence of serpentinites in the
subducting plate and/or mantle wedge.
It was rather intimidating to have to speak right after Nobu Shimizu, one of the big names
in the ionprobe community, and on top of that, presenting work about rocks from the same
locality as my work, but at least it guaranteed a large audience.
No matter the great success of the Goldschmidt conference, the star of the show was of
course the city of Florence itself, which may explain more than 4,000 delegates attending. It
is hard to image a better backdrop than Florence’s ancient stone architecture and the
Tuscan hills, plus fantastic Mediterranean food to revive the weary conference-goer. I want
to thank again the Mineralogical Society; without its support my attendance to this
conference and the SIMS workshop would have been impossible.
Left: The magnificent Duomo in Florence. Above:
Serpentinite in the Duomo façade.