Measurements and Instrumentation in the Stable Isotope Geochemistry Team

Scientific coordinator:  Magali Bonifacie

The analysis of the ∆₄₇ of carbonates consists in the measurement of the overabundance of the ¹³C–¹⁸O chemical bounds (relative to a stochastic distribution) in gaseous CO₂ produced via acid digestion of carbonates. The abundance of the ¹³C–¹⁸O bounds inside the carbonate lattice increases at low temperature and only depends on their temperature of crystallization or equilibration, thus providing a reliable paleo-thermometer. 

Field of research and associated publications

– Refinement of the accuracy of the ∆₄₇ thermometer and of its interpretationnal foundations (Bonifacie et al., 2017, Katz et al., 2017, Mangenot et al., 2017, Dassié et al., 2018, Pettersen et al., 2019, Bernasconi et al., 2021, Anderson et al., 2021, Huntington et al., 2011)

– Carbonate diagenesis (Bristow et al., 2011, Mangenot et al., 2017, Mangenot et al., 2018 a and b, Pagel et al., 2018, Bennet et al., 2018, Dassié et al., 2018, Fay-Gomord et al., 2018, Brigaud et al. 2020, Loyd et al., 2015, Kirschvink et al. 2015)

– Biomineralization (Katz et al., 2017, Thaler et al., 2020)

 – High temperature clumped isotope thermometry (Bristow et al., 2011, Bonifacie et al. 2017, Mangenot et al., 2019)

Analytical performance

Since 2013, we are routinely analyzing any type of carbonate (calcite, aragonite, dolomite…) with a precision better than ±0.014‰ (1 SD for 3 replicates). Each analysis requires 5 mg of carbonate powder. The measurement of ∆₄₇ is performed using a Thermo MAT 253 mass spectrometer after CO₂ extraction via H₃PO₄ digestion of carbonates, and purification of CO₂ on vacuum line.

List of publications

* Publication with data out of the IPGP laboratory
Student supervised
# Community papers

 2021

#* Anderson N.T., Kelson J.R., Kele S., Da¨eron M., Bonifacie M., Horita J., Mackey T.J, John., C.M., Kluge T., P. Petschnig11, Jost A.B., Huntington K.W, Bernasconi ., S.M., Bergmann K.D.  A unified clumped isotope thermometer calibration (0.5–1100°C) using carbonate-based standardization In press GRL

#* Bernasconi S.M., Daëron M., Bergmann K.D., Bonifacie M., Meckler A.N., Affek H.P., Anderson N., Bajnai D., Barkan E., Beverly E., Blamart D., Burgener L., Calmels D., Chaduteau C.,. Clog M., Davidheiser-Kroll B., Davies A., Dux F., Eiler J., Elliott B., Fetrow A. C., Fiebig J., Goldberg S., Hermoso M., Huntington K.W., Hyland E., Ingalls M., Jaggi M., John C.M., Jost A. B., Katz  S., Kelson J., Kluge T., Kocken I.J., Laskar A., Leutert T.J., Liang D., Lucarelli J., Mackey T. J., Mangenot X., Meinicke N., Modestou S.E., Müller I.A., Murray S., Neary A., Packard N., Passey B.H., Pelletier E., Petersen S., Piasecki A., Schauer A., Snell K.E., Swart P.K., Tripati A., , Upadhyay D., Vennemann T., Winkelstern I., Yarian D., Yoshida N., Zhang N., Ziegler M.  InterCarb: A community effort to improve inter-laboratory standardization of the carbonate clumped isotope thermometer using carbonate standards In press Geochemistry, Geophysics, Geosystem

2020

* Thaler C., Katz A., Bonifacie M., Ménez B., Ader M. Oxygen isotope composition of waters recorded in carbonates in strong clumped and oxygen isotopic disequilibrium (2020). Biogeosciences, 17, 1–14, 2020. DOI 10.5194/bg-17-1731-2020 

* Brigaud B., Bonifacie M., Pagel M., Blaise T., Calmels D., Haurine F., Landrein P. Past hot fluid flows in limestones detected by ∆₄₇/(U-Pb) and not recorded by other geothermometers, Geology, May 2020, Vol.48,851-856.

2019

 #* Petersen S.V., Defliese W.F., Saenger C., Daëron M., John C.M., Huntington K.W., Kelson J.R., Bernasconi S.M., Colman A.S., Kluge T., Olack G.A., Schauer A.J., Bajnai D., Bonifacie M., Breitenbach, S.F.M., Fiebig J., Fernandez A.B., Henkes G.A., Hodell, D., Katz A., Kele S., Lohmann K.C., Passey B.H., Petrizzo D.A., Rosenheim B.E., Tripati A.E., Venturelli R., Young E.D., Wacker U., and Winkelstern I.Z., Effects of Improved 17O Correction on Inter-Laboratory Agreement in Clumped Isotope Calibrations, Estimates of Mineral-Specific Offsets, and Acid Fractionation Factors Geochemistry, Geophysics, Geosystem 20 (7) 3495-3519. DOI: 10.1029/2018GC008127.

* Mangenot X., Deconinck J.F, Bonifacie M., Sizun J.P., Colin P.Y., Quesnes D., Charollais J., Rouchon V. (2019). Thermal and exhumation histories of the northern subalpine chains (Bauges and Bornes—France): Evidence from forward thermal modeling coupling clay mineral diagenesis, organic maturity and carbonate clumped isotope (Δ₄₇) data, Basin Research 31 (2) 361-379 DOI: 10.1111/bre.12324

2018

* Mangenot X., Gerdes A., Gasparrini M., Bonifacie M., Rouchon V. An emerging thermo-chronometer for carbonate-bearing rocks : Δ₄₇/(U-Pb). Geology 46 (12), 1067-1070. Doi: 10.1130/G45196.1

* Fay-gomord O., Allanic C., Wouter S., Honlet R., Champenois F., Bonifacie M., Chaduteau C., Muchez P., Verbiest M., Lasseur E., Swennen R. (2018) Understanding fluid-flow during tectonic reactivation: an example from the flamborough head chalk outcrop (UK) Geofluids, Article ID 9352143, 17 pages. DOI : 10.1155/2018/9352143/

*  Bennett, C. E., Williams, M., Leng, M. J., Lee, M. R., Bonifacie, M., Calmels, D., Fortey, R.A., Laurie, J.R., Owen, A. W., Page A.A., Munnecke A.,Vandenbroucke, T.R.A. (2018) Oxygen isotope analysis of the eyes of pelagic trilobites: testing the application of sea temperature proxies for the Ordovician. Gondwana Research, 57, 157-169

* Dassié E. Genty, D., Noret, A., Mangenot, X., Massault, M., Lebas, N., Duhamel, M., Bonifacie, M., Gasparrini, M., Minster B., and Michelot, J.L. (2018) A newly designed analytical line to examine the reproducibility of fluid inclusion isotopic compositions in small carbonate samples. Geochemistry, Geophysics, Geosystems, 19 (4) 1107-1122. DOI: 10.1002/2017GC007289

* Pagel M., Bonifacie M., Schneider D.A., Gautheron C., Brigaud B., Calmels D., Chaduteau C., Cros A., Saint-Bezar B., Landrein P., Davis D. (2018) Improving paleohydrological and diagenetic reconstructions in calcite veins and breccia of a sedimentary basin by combining Δ47 temperature, δ18Owater and U-Pb age. Chemical Geology 487, 1-17. DOI: 10.1016/j.chemgeo.2017.12.026

* Mangenot X., Gasparrini M., Rouchon V., Bonifacie M. (2018) Basin-scale thermal and fluid-flow histories revealed by clumped isotope (Δ₄₇) – Middle Jurassic reservoirs of the Paris Basin. Sedimentology Vol. 65 (1), 123-150. DOI: 10.1111/sed.12427

2017

 * Mangenot X., Bonifacie M., Gasparrini M., Goetz A., Ader M., Chaduteau C., Rouchon V. Coupling Δ47 and fluid inclusion thermometry on carbonate cements to precisely reconstruct the temperature, salinity and δ¹⁸O of paleo-groundwater in sedimentary basins. (2017) Chemical Geology 472, 44–57. DOI : 10.1016/j.chemgeo.2017.10.011

* Katz A., Bonifacie M., Hermoso M., Cartigny P., Calmels D. (2017) Laboratory-grown coccoliths exhibit no vital effect in clumped isotope (Δ₄₇) composition on a range of geologically relevant temperatures Geochimica Cosmochimica Acta , 208, 335–353. DOI :10.1016/j.gca.2017.02.025

* Bonifacie M., Calmels D., Eiler J.M., Horita, J., Chaduteau C., Vasconcelos, C., Agrinier, P., Katz A., Passey, B.H., Ferry J.M., Bourrand J.J. (2017) Experimental calibration of the dolomite clumped isotope thermometer from 25 to 350°C, and implications for a universal calibration for all (Ca, Mg, Fe)CO3 carbonates. Geochimica Cosmochimica Acta, 200, 255-279.  DOI : 10.1016/j.gca.2016.11.028

2015

Loyd S., Corsetti F., Eagle R.A., Hagardorn J.W., Shen Y., Zhang X. Bonifacie, M., Tripati A. K. 2015. Origins of the Neoproterozoic Wonoka-Shuram anomaly from clumped isotope paleothermometry, Precambrian Research 264, 179-191.

Kirschvink J., Isozaki Y., Shibuya H., Raub T., Hilburn I., Yokoyama M., Bonifacie, M. Challenging the sensitivity limits of Paleomagnetism: Magnetostratigraphy of Weakly-Magnetized Guadalupian-Lopingian (Permian) Limestone from Kyushu, Japan, Palaeogeography, Palaeoclimatology, Palaeoecology, 418, 75–89.

2011

Bristow, T.F., Bonifacie, M., Derkowski, A. Eiler, J. M. Grotzinger, J.P. 2011 A hydrothermal origin for isotopically anomalous cap dolostone cements from south China, Nature, 474, 68-71.

2009

Huntington, K., Eiler J., Affek H., Bonifacie, M., Guo, W., Yeung L., Thiagarajan N., Passey B., Tripati, A., Daeron M., Came R. 2009 Methods and limitations of analyses of « clumped » CO2 isotopes (D47) by gas source isotope ratio mass spectrometry, Journal of Mass Spectrometry, 44, 1318-1329.

In 2017 we have co-organized the VIth International Clumped Isotope Workshop at IPGP https://www.ipgp.fr/en/iciw

For further information, feel free to contact Magali Bonifacie

Scientific coordinator : Magali Bonifacie
Lab Manager : Gérard Bardoux

• The Chlorine stable isotope

The Chlorine stable isotope lab at IPGP has been founded in the early 2000’s, at the very beginning of the emergence of this new geochemical tool, and thus has largely participated to the worldwide current knowledge on Cl isotope systematics. Since then, our high analytical performances ay IPGP have allowed to encompass a broad field of research.

Field of research led at IPGP and associated publications

– The geodynamic cycle of chorine (Bonifacie et al., 2005, 2007a et b, 2008a et b)

– Magmatism, volcanism, hydrothermalism (Bonifacie et al., 2005, Bonifacie et al., 2007, Bonifacie et al., 2008a, Li et al., 2015, Manzini et al., 2017, Stephan et al., 2020, Benard et al., 2021)

– Transport processes in fluids (Godon et al. 2004b, Lavastre et al. 2005, Woule Ebongue 2005, Bonifacie et al 2007, Bernachot et al., 2017; Giunta et al., 2017, Agrinier et al., 2019, Agrinier et al., 2021)

– Method development for chlorine and bromine measurements in various materials (Bonifacie et al., 2007, Giunta et al. 2015, Louvat et al. 2015, Gilevska et al., 2015, Horst et al., 2019)

– Determination of isotopic fractionation (Eggenkamp et al., 2016, Giunta et al., 2017, Agrinier et al., 2021)

– Standardisation for accurate δ³⁷Cl measurements (Godon et al. 2004a, Bonifacie et al., 2007, Gilevska et al., 2015, Manzini et al., 2017, Wudarska et al., 2021, etc)

– Evaporites (Eggenkamp et al., 2019a, 2019b)

Analytical performances

Chlorine isotope compositions (ratio ³⁷Cl/³⁵Cl) of fluids and gases) are routinely measured with high analytical precision of ±0.03‰ (1SD) for samples containing ≥ 180 µg Cl. Smaller samples can be analyzed with lower precision.

The chlorine isotope analyses require a transformation of chlorides into gaseous CH₃Cl, which is then analyzed with a Thermo Fisher Delta V mass spectrometer.

For rock samples, a first step requires the extraction of Cl contained in the sample via pyrohydrolysis and transformation into chlorides (details in Bonifacie et al., 2007).

Lab’s publications (δ³⁷Cl data out of IPGP lab only)

Lab members (permanent or transitory) are in bold font.

Wudarska, A.; Słaby, E.; Wiedenbeck, M.; Barnes, J.D.; Bonifacie, M.; Sturchio, N.C.; Bardoux G. Coufignal, F.; Glodny, J.; John, T.; Kusebauch, C.; et al. (2021) Inter-Laboratory Characterization of Apatite Reference Materials for Chlorine Isotope Analysis. Geostandard and Geoanalytical Research. doi: 10.1111/ggr.12366

Muller E. et al. (dont Bardoux G. and Ader M.) The origin of continental carbonates in Andean salars: A multi-tracer geochemical approach in Laguna Pastos Grandes (Bolivia). Geochimica Cosmochimica Acta, 279, 220-237. DOI: 10.1016/j.gca.2020.03.020

Benard, B., Famin, V., Agrinier, P., Aunay, B., Lebeau, G., Sanjuan, B., Vimeux, F., Bardoux, G., Dezayes, C., 2020. Origin and fate of hydrothermal fluids at Piton des Neiges volcano (Réunion Island): A geochemical and isotopic (O, H, C, Sr,Li, Cl) study of thermal springs. Journal of Volcanology and Geothermal Research, 382, 1-36. https://doi.org/10.1016/j.jvolgeores.2019.106682

Horst A., Bonifacie M., Bardoux G., Richnow H.H.  Isotopic characterization (²H, ¹³C, ³⁷Cl, ⁸¹Br) of the abiotic sinks of methyl bromide and methyl chloride in water and implications for future studies (2019). Environmental Science and Technology, 53 (15), 8813-8822. DOI: 10.1021/acs.est.9b02165

Stephant A., Anand M., Zhao X., Chan Q., Bonifacie M., Franchi I. The chlorine isotopic composition of the Moon: Insights from melt inclusions, Earth and Planetary Science Letters  523 (2019) # 115715. DOI: 10.1016/j.epsl.2019.115715

Eggenkamp HGM, Louvat P, Agrinier P., Bonifacie M., Bekker A., Griffioen J., Horita J., Brocks JJ, Bagheri R. (2019). The bromine and chlorine isotope composition of primary halite deposits and its consequence for the historical isotope composition of seawater, Geochimica Cosmochimica Acta, 264, 13-29. DOI: 10.1016/j.gca.2019.08.005

Agrinier P. Destrigneville, C., Giunta, T., Bonifacie, M., Bardoux, G., André J., Lucazeau, F. (2019). Chlorine stable isotope ratios (35Cl/37Cl) of chlorides of fluids produced in low permeability clay rich sediments: the potential role ion-filtration. Geochimica Cosmochimica Acta, 245, 525-541 DOI: 10.1016/j.gca.2018.11.013

Giunta T., Devauchelle O., Ader M., Locke R., Louvat P., Bonifacie M., Métivier F., Agrinier P. The gravitas of gravitational isotope fractionation  revealed in an isolated aquifer. (2017) Geochemical Perspective Letters 4, 53-58. DOI:10.7185/geochemlet.1736.

Giunta T., Labidi J. Eggenkamp H., (2017) Chlorine isotope fractionation between chloride (Cl^–) and dichlorine (Cl₂) Geochimica Cosmochimica Acta, 213, 375-382 http://dx.doi.org/10.1016/j.gca.2017.07.003

Bernachot, I., Garcia, B., Ader, M., Peysson, Y., Rosenberg E., Bardoux, G., Agrinier, P., 2017. Solute transport in porous media during drying: The chlorine isotopes point of view. Chemical Geology, 466, 102-115 http://dx.doi.org/10.1016/j.chemgeo.2017.05.024

Manzini M., Bouvier A.-S., Barnes J., Bonifacie M., Rose-Koga E. F., Ulmer P., Métrich N., Bardoux G., Williams J., Layne G.D., Straub S., Sharp Z., Baumgartner L.P. John, T. (2017) SIMS chlorine isotope determination in melt inclusions from arc settings. Chemical Geology 449, 112–122. http://dx.doi.org/10.1016/j.chemgeo.2016.12.002

Ivdra N., Fischer A., Herrero-Martin S., Giunta T., Bonifacie M., Richnow H.H. Carbon, hydrogen and chlorine stable isotope fingerprinting for forensic investigation on Hexachlorocyclohexanes. (2017) Environ. Science & Technology 51, 446-454. DOI: 10.1021/acs.est.6b03039.

Bonifacie M. Chlorine Isotopes (2017). In Encyclopedia of Geochemistry – Editor William White, Publisher Springer

Louvat P., Bonifacie M., Giunta T., Michel A. Coleman M. Determination of Bromine stable isotope ratios from saline solutions by « wet plasma » MC-ICPMS including a compaison between high- and low-resolution modes, and three introduction systems. 2016. Analytical Chemistry 88 (7), 3891-3898. DOI: 10.1021/acs.analchem.6b00062

Eggenkamp H., Bonifacie M., Ader M., Agrinier P. Experimental determination of stable chlorine and bromine isotope fractionation during precipitation of salt from a saturated solution. 2016. Chemical Geology 433, 46-56. http://dx.doi.org/10.1016/j.chemgeo.2016.04.009

Giunta T., Ader, M., Bonifacie, M., Agrinier, P., Coleman, (2015) M. Pre-concentration of chloride in dilute water-samples for precise δ37Cl determination using a strong ion-exchange resin, Chemical Geology 413, 86–93 10.1016/j.chemgeo.2015.08.019

Gilevska T., Ivdra N., Bonifacie M., Richnow H.H. 2015. Optimization of organochlorines’ conversion for Cl DI-IRMS measurements (2015). Rapid Communication in Mass Spectrometry 29, 1343–1350. DOI: 10.1002/rcm.7220

Li, L., Bonifacie, M., Aubaud C., Crispi O., Dessert C., Agrinier P. (2014) Chlorine isotopes in thermal springs of arc volcanoes for tracing shallow volcanic activity, Earth and Planetary Science Letters 413, 101-110. http://dx.doi.org/10.1016/j.epsl.2014.12.044

Bonifacie, M., N. Jendrzejewski, P. Agrinier, E. Humler, M. Coleman, M. Javoy, 2008 The chlorine isotope composition of the Earth’s mantle, Science, Vol. 319. no. 5869, 1518 – 1520. 10.1126/science.1150988

Bonifacie, M., V. Busigny, P. Philippot, C. Mével, P. Agrinier, M. Scambelluri, N. Jendrzejewski, M. Javoy 2008 Chlorine isotopic composition in seafloor peridotites and high-pressure metaperidotites: insights into the oceanic serpentinization and subduction processes, Geochim. Cosmochim. Acta, 72, 1, 126-139. doi:10.1016/j.gca.2007.10.010

Bonifacie, M., Jendrzejewski N., Agrinier P., Coleman M., Pineau F., Javoy M.; Pyrohydrolysis-IRMS determination of silicate δ37Cl compositions: application to oceanic crust and meteorite samples, Chem. Geology, 242, (2007; 187-201. doi:10.1016/j.chemgeo.2007.03.012 

Bonifacie, M., C. Monnin, N. Jendrzejewski, P. Agrinier, M. Javoy, Chlorine stable isotopic composition of basement fluids of the Eastern flank of the Juan de Fuca ridge (ODP Leg 168), EPSL. 260, 1-2 (2007); 10-22. doi:10.1016/j.epsl.2007.05.011

Lavastre, V., Jendrzejewski, N., Agrinier, P., Javoy, M., Evrard, M., 2005. Chlorine transfer out of a very low permeability clay sequence (Paris Basin, France): ³⁵Cl and ³⁷Cl evidence. Geochim. Cosmochim. Acta 69, 4949–4961. doi:10.1016/j.gca.2005.04.025

Woulé Ebongué, V., Jendrzejewski, N., Walgenwitz, F., Pineau, F., Javoy, M., 2005. Chlorine isotope residual salt analysis (Cl-RSA): a new tool to investigate formation waters from core analyses. AAPG Bulletin, Geological Note, vol. 89, pp. 1005–1018. DOI:10.1306/03100504040

Bonifacie, M., Charlou J.L., Jendrzejewski N., Agrinier P., J.P. Donval. Chlorine isotopic compositions of high temperature hydrothermal vent fluids over ridge axes Chem. Geology, 221 (2005); 279-288. doi:10.1016/j.chemgeo.2005.06.008

Godon, A., Jendrzejewski, N., Castrec-Rouelle, M., Dia, A., Pineau, F., Boulègue, J., Javoy, M., 2004b. Origin and evolution of fluids from mud volcanos in the Barbados accretionary complex. Geochim. Cosmochim. Acta 68, 2153–2165. doi:10.1016/j.gca.2003.08.021

Godon, A., Jendrzejewski, N., Eggenkamp, H.G.M., Banks, D.A., Ader, M., Coleman, M.L., Pineau, F., 2004a. A cross-calibration of chlorine isotopic measurements and suitability of seawater as the international reference material. Chem. Geol. 207, 1–12. doi:10.1016/j.chemgeo.2003.11.019

Review article

Bonifacie M. Chlorine Isotopes (2017). In Encyclopedia of Geochemistry – Editor William White, Publisher Springer

PhD thesis and students

Arnaud Godon 2001
Véronique Lavastre 2001
Véronique Woulé Ebongué 2004
Magali Bonifacie 2005
Thomas Giunta 2015
Isabelle Bernachot 2017
Etienne Le Glas PhD expected for 2023
Laetitia Guibourdenche PhD expected for 2022

• Bromine isotope

Bromine isotope composition (⁸¹Br/⁷⁹Br) of fluids can be measured by two different techniques depending on the sample size and chemical characteristics:

– Gas source mass spectrometry: bromide dissolved in solution must be transformed into CH₃Br (gaseous form), which can be analyzed on the mass spectrometer (Delta Plus XP, Delta V). Prior to isotope analysis, Br is separated from Cl (with Cl/Br ratio of ~300 in natural samples). The ratio ⁸¹Br/⁷⁹Br can presently be measured using IRMS with an external analytical precision of 0.1‰ (2SD), for an amount of 3-4 mg of Br.

– MC-ICP-MS : the ratio ⁸¹Br/⁷⁹Br is measured ny MC-ICP-MS with a precision ranginf from 0.1 to 0.5 ‰ (2SD) for low amount of Br (10-50 µg). We are developping a new protocol for bromine chemical extraction using chromatography, allowing us to separate efficiently Br from Cl in highly enriched matrix such as seawater (the ratio Cl/Br of ~300 is lowered to 10).

For further information, feel free to contact Magali Bonifacie, Gérard Bardoux.

Since the 1980s, our team has put strong effort in the development of nitrogen isotope analysis (ratio ¹⁵N/¹⁴N) on very small samples, down to 1000 times lower than usual conditions. We have been able to routinely measure isotope composition of only few nanomoles of nitrogen, included in different types of matrix (diamonds, anthracite, graphite, organic matter, silicates…) with a precision better than ±0.5 ‰ (2 SD).

The analysis of very small samples is performed on our static mass spectrometer after online gas extraction. Another vacuum line is available and allows the preparation of sealed tubes for N analysis in various sample types. The sample size is typically of few mg (diamonds, graphite, anthracite) to few tens of mg (silicates).

The isotope composition of samples enriched in nitrogen, such as organic matter-rich sediments, is routinely measured via elemental analyzer (few mg of samples) and/or other extraction lines specifically designed for N-rich samples (> 1 μmol of nitrogen) and mass spectrometry (Delta Plus XP). The external reproducibility of samples and standards typically around ± 0.3 ‰ (2 SD).

For further information, feel free to contact Magali Ader, Vincent Busigny, Pierre Cartigny et Virginia Rojas.

Carbon isotope composition (ratio ¹³C/¹²C) of many samples (sediments, metasediments, rocks from altered oceanic crust, soils, particles…) are routinely measured for two different carbon species, organic carbon (reduced form) and carbonates (oxidized form). Both species are analyzed specifically, although bulk-rock analysis is also possible. We also analyze the isotope composition of dissolved inorganic carbon in terrestrial fluids (hydrothermal systems, lakes, rivers).

The analysis of organic carbon generally requires a sample treatment under acidic conditions (HCl) in order to remove any carbonate present in the sample. The analysis is then performed on the solid-residue of acid digestion, by a sealed-tube combustion technique or elemental analyser coupled to a mass spectrometer (Delta Plus XP, Delta V).

The carbonates (calcite, dolomite, magnésite, ankérite, sidérite) are generally analyzed by He continuous flow mass smectrometry (AP2003), after carbon extraction and transformation into CO2 by H₃PO₄ acidification.

For samples with low C concentration, such as those from oceanic crust (typically containing few hundred’s of ppm CO₂), we developped a step-heating technique for C extraction, using either pyrolisis of combustion, at temperature ranging from 250 to 1100°C. This type of analysis requires only low amount of rock powder (50 to 100mg), and is thus also suitable for small size samples such as those produced during laboratory experiments. Carbon isotopes of diamonds are also routinely analyzed by combustion on samples generally between 0.02 to 3 mg.

The analytical precision on C isotope composition is typically of ± 0.03 ‰.

For analysis of dissolved inorganic carbon (DIC) in fluids, a technique was developped allowing extraction of dissolved C species in the form of CO₂ by sample acidification using H₃PO₄. The gas is analyzed on our He continuous flow mass spectromer with a precision better than ±0.1 ‰ for DIC > 1mM, and a precision of about ±0.3 ‰ for DIC < 0.5 mM.

For further information, feel free to contact Magali Ader, Isabelle Martinez, Vincent Busigny, Magali Bonifacie, Cyril Aubaud, Pierre Cartigny, Virginia Rojas and Nelly Assayag.

Hydrogen isotope (D/H ratio) compositions of rocks are measured, after extraction (heating) under vacuum and reduction on hot uranium at 800°C. The quantities of hydrogen are generally about tenth of micromoles of H2, corresponding for instance to 300 mg of glass for concentration of ~ 2500 ppm H2O. The analytical precision is about ±3 ‰.

We can also measure water samples (e.g.  for calibration of uranium furnaces) but the analyses are not optimized for large sample set.

For further information, feel free to contact Cyril Aubaud and Pierre Agrinier.

Oxygen isotope composition (ratios ¹⁷O/¹⁶O and ¹⁸O/¹⁶O on the molecule O₂) of silicates and oxides can be measured in our laboratory by fluorination (F₂, BrF₅) in classical nickel bombs or fluorination coupled to laser ablation. The typical sample size is respectively 10 mg and 2 mg, and the analysis by mass spectrometry (MAT 253, Delta Plus XP or Delta V) provides precisions of about ±0.07 and ±0.02 ‰ (2 SD) respectively for δ¹⁸O and ∆¹⁷O.

The ratio ¹⁸O/¹⁶O in water samples is routinely measured using a technique based on CO₂ equilibration with water, and He continuous flow mass spectrometry (via either GasBench or AP2003). The analysis is performed on water samples of ~1 mL, and gives a precision better than ± 0.2 ‰ on the δ¹⁸O value.

The isotope ratio ¹⁸O/¹⁶O of carbonates is analyzed, together with C isotopes (see “Analysis of carbon isotope composition) on sample powders of ~2 mg (for pure carbonates). The technique is based on sample acidification using H₃PO₄ allowing CO₂ gas extraction. Then, the CO₂ is analyzed by He continuous flow mass spcetrometry (AP2003) with a precision of ± 0.1 ‰ (2 SD).

For further information, feel free to contact Pierre Agrinier, Cyril Aubaud, Pierre Cartigny y Nelly Assayag.

Sulphur isotope compositions (³³S/³²S, ³⁴S/³²S et ³⁶S/³²S on the SF₆ molecule) of sulphides, sulphate, organic or dissolved sulphur in glasses is carried out after extraction/chemical conversion to silver sulphide (Ag₂S) and fluorination in nickel bombs, cryogenic and gas chromatography purification, and analysis by mass spectrometry (MAT 253).

The amounts required are, routinely, > 6 μmol (1.5 mg Ag₂S) but we have successfully analysed samples down to 0.1 μmol (for ³³S/³²S, ³⁴S/³²S and ³⁶S/³²S) and are completing the validation of a protocol for analysis of a few nanomoles (for ³³S/³²S, ³⁴S/³²S ratios).

The analysis of sulphates and sulphides or organic sulphur (³⁴S/³²S) is also possible by an elemental analyser coupled to the mass spectrometer (Delta Plus XP).

For further information, feel free to contact Jabrane Labidi and Pierre Cartigny. 

The GIS group is equipped with a Picarro L2140-i laser spectrometer for the measurement of the isotopic composition of water ((δ ¹⁸O, δ ¹⁷O, δD). The measurement is done by vaporization of a liquid water sample with a volume of 1-2 ml. The isotopic composition of water is used as a tracer of a very large number of processes of interest to the Earth Sciences.

Multiple applications include:

• the formation of hydrated minerals by evaporation from seawater
• tracing the continental hydrological cycle
• the functioning of volcanoes and hydrothermal systems

The Picarro L2140-i laser spectrometer is part of the High-Resolution Analysis Platform of IPGP (PARI platform).

For further information, feel free to contact Giovanni Aloisi.