Highligths

Volcanic Gases do not Reflect the Redox State of Magmas!
Using precise, FTIR based, gas compositions, allows calculation of T-fO2. Results obtained at Kilauea volcano show conclusively that the gas redox state drift away from magma redox state as it cools down prior to mixing with the atmosphere

Oppenheimer, O.,  Scaillet, B., Woods, A., Sutton, A.J., Elias, T., and Moussallam, Y. (2018). Influence of eruptive style on volcanic gas emission chemistry and temperature. Nature Geosciences, https://doi.org/10.1038/s41561-018-0194-5

Determining the Rates of Fluid Circulation in the Crust during Ore Production

 

Using tourmaline as a monitor of fluid velocities during crystal growth. Here are shown examples of basal sections of tourmaline from veins (a) and altered wall-rocks (b) displaying an asymmetric shape caused by an anisotropic growth. (c) Measurements of growth bands thickness and orientation on a basal section of tourmaline. (d) Curve deduced from numerical modeling showing relationship between fluid velocity and flux ratio (see paper for details). The filled boxes indicate range of averages of fluid velocities derived from dmax/dminratio measured on tourmalines from altered wall-rocks (blue) and veins (red).

Launay, G.,  Sizaret, S., Guillou-Frottier, L., Gloaguen, E., Pinto, F. (2018). Deciphering fluid flow at the magmatic-hydrothermal transition: A case study from the world-class Panasqueira W–Sn–(Cu) ore deposit (Portugal). Earth and Planetary Science Letters, 499, 1–12

Measuring Aerosols in the Atmosphere
SEM pictures of aerosols produced by different contexts worldwide

Renard, JB., et al 2016; LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 1: Principle of measurements and instrument evaluation. Atmospheric Measurement Techniques, 9, 1721–1742, 2016 www.atmos-meas-tech.net/9/1721/2016/doi:10.5194/amt-9-1721-2016

Relating Conductive Anomalies in the Crust to Fluid/Melt Occurrences in the Himalayas
The determination of electrical properties of hydrous leucogranite melts show them to be similar to magnetotelluric anomalies (bright spots) imaged by geophysical surveys in the mid crust of the Himalaya-Tibetan collisional range, suggesting that the latter correspond to present-day partially melted crust, similar to Miocene Leucogranites outcropping at Everest or Manaslu peaks.

Chen, J., Gaillard, F.,  Villaros, A., Yang, X., Laumonier, M.,  Jolivet, L.,  Unsworth, M.,  Hashim, L.,  Scaillet, B. and Richard, G. (2018), Melting conditions in the modern Tibetan crust since the Miocene Nature Communications, in press

Water trapped in large pores is not bulk water!
Using a 3×3 µm IR micro-beam (SOLEIL, SMIS beamline), a precise maps of the OH-stretching band of liquid water was mapped ion pure water trapped in a pure quartz synthetic inclusion. Liquid water nowhere showed the bulk signature (red band top right), and displayed a strongly different signature along the borders, corresponding to a 1.5 kJ/mol thermodynamic shift

Bergonzi I., Mercury L, Simon P., Jamme F., Shmulovich K.I. (2016) Oversolubility within the microvicinity of solid-solution interfaces. Physical Chemistry Chemical Physics 18, 14874-14885. https://doi.org/10.1039/C5CP08012F.

Modelling halogens behaviour during mixing between volcanic plumes and the atmosphere
Distance–pressure cross section of the SO2, OH, HBr, BrO, O3 and NOx mixing ratios in the plume of Ambrym on 12 January 2005 at 06:00 UTC in the simulation S1_HighT (Jourdain et al., 2016)

Jourdain, L., Roberts, T.J.,, Pirre, M., and Josse, B. (2016). Modeling the reactive halogen plume from Ambrym and its impact on the troposphere with the CCATT-BRAMS mesoscale mode. Atmospheric Chemistry and Physics, 16, 12099–12125, 2016 www.atmos-chem-phys.net/16/12099/2016/ doi:10.5194/acp-16-12099-2016

Mixing Hydrous Arc Magmas at High Pressure and the Origin of Andesites
Deformation of either dry of hydrous juxtaposed mafic and felsic magmas at high pressure shows that mixing occurs only when there is no more viscosity contrast between the two end-members

Laumonier, M., Scaillet, B., Pichavant, M., Champallier, R., Andujar, J., and Arbaret, L. (2014). On the conditions of magma mixing and its bearing on andesite production in the crust. Nature Communications, DOI: 10.1038/ncomms6607

Deciphering the Relationships Between Mantle Flow, Crustal Dynamics and Magma Genesis

 

Results of 3D numerical simulations of the evolution of a subduction zone in the Aegean area, illustrating the effect of slab tearing, continental collision and magma plume initiation above the downgoing slab

Menant, A., Sternai, P., Jolivet, L., Guillou-Frottier, L., and Gerya, T. (2016). 3D numerical modeling of mantle flow, crustal dynamics and magma genesis associated with slab roll-back and tearing: The eastern Mediterranean case. Earth and Planetary Science Letters 442, 93–107

Atmospheric Release of Massive Amounts of Halogens by Major Volcanic Eruptions Creates an Ozone hole Lasting Leveral Years
Modelled percentage changes in stratospheric chlorine column following the Minoan eruption as a function of time (years) and latitude. a For the minimum volatiles scenario (i.e., no pre-eruptive fluid phase). b For the maximum volatiles scenario (i.e., including a pre-eruptive fluid phase). ‘Chlorine column’ = vertically integrated concentration of chlorine. Cly = concentration of total inorganic stratospheric chlorine = HCl + ClONO2 + ClO + 2 Cl2O2 + OClO + 2 Cl2 + Cl + HOCl + BrCl. The black cross indicates the latitude of the Santorini eruption (Cadoux et al., 2015)

Cadoux, A;, Scaillet, B., Bekki, S., Oppenheimer, C., and Druitt, T.H. (2015). Stratospheric Ozone destruction by the Bronze-Age Minoan eruption (Santorini Volcano, Greece), Scientific Reports, | 5:12243 | DOI: 10.1038/srep12243