BRISOACTIONS
This project has received funding from the European Union's Horizon
2020 research and innovation program under the Marie
Sklodowska-Curie grant agreement No 702001.
The research has been carried out at the Institut de Physique du Globe de
Paris, Équipe
de Geochimie des Isotopes Stables.
Experienced researcher: Dr Hans Eggenkamp
Supervisor: Prof Pierre Agrinier
To understand the redox variations and
interactions between hydro-, bio- and atmosphere: the power of
bromine stable isotopes.
The stable isotope geochemistry of chlorine (Cl) and bromine (Br)
are considerably different. While most Cl isotope data are in the
range from -1.21 to +0.40‰, Br isotope data are from -0.06 to
+1.48‰. Interesting is that Br isotope variations are of the same
magnitude as Cl isotope variations. Also Br isotope values of
ancient evaporites are very positive (+0.6‰), impossible to explain
from oceans with a modern isotope composition. These data are
unexpected considering the small fractionation factors for Br
compared to Cl.
The research we propose aims at understanding these observations and
developing halogen stable isotopes to study fluid transport
processes in porous media. This research has a great potential to
understand the history and the migration of fluids in deep porous
reservoirs which are considered for geological storage of CO2, H2
and hydrocarbons.
In the BRISOACTIONS project we study historical variations of Br
isotope compositions in the earth's surface reservoirs. We study Br
isotope variations in ancient evaporites that reflect Br isotope
ratios of the oceans at the moment they were deposited.
We also study the geochemical processes that affect Cl and Br
isotope variations. Isotope fractionation during ion-filtration that
has never been studied in detail. This process is important to
understand subsurface fluid flow and fractionation of ions and
isotopes during fluid transport. We aim at studying Cl and Br
isotope variations during this process. Also redox processes have
hardly been studied. Oxidation processes can increase Br isotopes
values more than Cl in spite of Br's much smaller isotope
fractionation factors. During the early stage of the BRISOACTIONS
project it became obvious that large Br isotope variations can be
obtained through precipitation of salt from saturated solutions. At
that moment we started to focus on those studies and
oxidation-reduction research was stalled for possible later stages.
The final stage of the BRISOACTIONS project is to combine the new
data with pre-known Br isotope geochemistry. So our observations we
will be compared to the data obtained during earlier studies in
order to understand better the geochemical cycles of Cl and Br. This
will allow us to develop future research to continue to improve our
knowledge on Cl and Br isotope variations as proxies to understand
chemical cycles on earth, especially in fluids in deep porous
reservoirs. To facilitate the comparison of new with older data we
prepared a database containing all samples (published and as yet
unpublished) from which Cl and Br isotope data are known.
On this website we present the results from the BRISOACTIONS
project. The results that are presented and that are based on this
project will be available from this website.
Published papers:
HGM Eggenkamp & P Louvat (2018) A
simple distillation method to extract bromine from natural water
and salt samples for isotope analysis by multi collector
inductively coupled plasma mass spectrometry. Rapid
Communications in Mass Spectrometry, 32;612-618 DOI:10.1002/rcm.8080.
Conference presentations:
First EAGE Workshop on Geochemistry in Operations and Production;
Doha, Qatar, 3 to 5 October 2016 - Application
of Cl and Br stable isotope variations in understanding aqueous
fluids in sedimentary basins.
Goldschmidt 2017; Paris, France, 13 to 18 August 2017 - Relationships
between δ81Br and δ37Cl in natural water and
salt samples.
European Geosciences Union; Vienna, Austria, 8-13 April 2018 - Bromine
stable isotope fractionation in evaporites.
Benelux Association of Stable Isotope Scientists; Liège, Belgium,
19-20 April 2018 - The
fractionation of the stable isotopes of bromine in evaporites. (50M!!)
Database
of all samples from which both the Cl AND the Br isotope ratio has been
published. The database also contains the chemcial compositions of the
samples so that relationships between the chemsitry and isotope
compositons can be studied too.