In-situ measurements of magmatic volatile elements, F, S, and Cl, by electron microprobe, secondary ion mass spectrometry, and heavy ion elastic recoil detection analysis

Abstract

Electron probe and ion probe are the two most used instruments for in situ analysis of halogens in geological materials. The comparison of these two methods on widely distributed glass standards (example: MPI-DING glasses, Jochum et al., G-cubed, 2006) provides a basis for establishing laboratory method, independent geochemical data sets for these elements. We report analyses of F, S, and Cl concentrations in three geological glass samples (EPMA) and 10 referenced standards (EPMA and SIMS). Furthermore, F and Cl absolute abundances have been determined independently for three of the standards (KL2-G, ATHO-G, and KE12), via heavy ion elastic recoil detection analysis (HIERDA), to certify the accuracy of the cross-calibration EPMA-SIMS. The detection limits for EPMA are a 150 μg·g-1 for F, 20 μg·g-1 for S and Cl, and for SIMS < 48 μg·g-1 for F, < 3 μg·g-1 for S, and <19 μg·g-1 for Cl. On SiO2-rich glass-standards, F and Cl measurements by HIERDA highlight a weak matrix effect during SIMS analysis of F and Cl. With the HIERDA independently measured value, we therefore propose an alternative calibration function to empirically correct this matrix effect on the SIMS measurements of F, S, and Cl.

How to turn off a lava lake? A petrological investigation of the 2018 intra-caldera and submarine eruptions of Ambrym volcano

“…Volatile (H2O, CO2, Cl, F, S) content in melt inclusions, embayments, and matrix glasses were determined using a Cameca IMS 1280 ion microprobe at CRPG-CNRS-Nancy. Analytical conditions were similar to other volatile studies (e.g., Hauri et al 2002;Bouvier et al 2008;Shimizu et al 2009;Rose-Koga et al 2014, 2020Moussallam et al 2015bMoussallam et al , 2019. Details of all three methods are provided in the supplementary.…”

“…If we look in detail at the last three eruptions that terminated or partially drained lava lakes at basaltic volcanoes along a rift axis -2020Erta 'Ale, 2018Kīlauea and 2018, clear patterns seem to emerge. First, they all seem to be preceded by high levels of their lava lake.…”

Halogen Bearing Amphiboles, Aqueous Fluids, and Melts in Subduction Zones: Insights on Halogen Cycle From Electrical Conductivity

“…The electron probe microanalysis was conducted with an accelerating voltage of 15 kV and a beam current of 20 nA. F and Cl were measured by electron microprobe using three Fe interference‐free thallium acid phthalate (TAP) crystals (Rose‐Koga et al., 2020). The concentrations of F and Cl in the four natural amphibole samples were also determined using an IMS 1270 secondary‐ion mass spectrometer (SIMS) at Center de Recherches Pétrographiques et Géochimiques (CRPG) Nancy, France.…”

High-pressure homogenization of olivine-hosted CO<sub>2</sub>-rich melt inclusions in a piston cylinder: insight into the volatile content of primary mantle melts

“…Major elements analyses of olivine were performed with a 1 µm diameter focused beam and a current of 15 nA, whereas melt inclusions were analyzed using a defocused beam of 5-10 µm diameter and a current of 4-8 nA. Volatiles were measured with a 5 µm beam size and a 40 nA current (Rose-Koga et al, 2020) after all other analyses have been performed.…”