TY  - JOUR
A1  - Farges, Francois
A1  - Djanarthany, S
A1  - de Wispelaere, S
A1  - Munoz, Manuel
A1  - Magassouba, B
A1  - Haddi, A
A1  - Wilke, Max
A1  - Schmidt, C.
A1  - Borchert, Manuela
A1  - Trocellier, P
A1  - Crichton, W
A1  - Simionovici, Alexandre
A1  - Petit, Pierre-Emanuel
A1  - Mezouar, Mohamed
A1  - Etcheverry, M. P.
A1  - Pallot-Frossard, I
A1  - Bargar, John Reeder
A1  - Brown, G. E.
A1  - Grolimund, D
A1  - Scheidegger, A
T1  - Water in silicate glasses and melts of environmental interest : from volcanoes to cathedrals
N2  - In silicate glasses and melts, water acts according to two main processes. First, it can be dissolved in high temperature/high pressure melts. Second, it constitutes a weathering agent on the glass surface. A number of in-situ x- ray absorption fine structure (XAFS) studies for Fe, Ni, Zr, Th and U show that the more charged cations (Zr, Nb, Mo, Ta, Sn, Th and U) are little affected by the presence of dissolved water in the melt. In contrast, divalent iron and nickel are highly sensitive to the presence of water, which enhance nucleation processes, for example, of phyllosilicates at the angstrom-scale. Such information provides additional constraints on the role of water deep in the Earth, particularly in magmatology. By contrast, the weathering of glass surfaces by water can be studied from a durability perspective. Experimental weathering experiments Of nuclear waste glasses performed in the laboratory show a variety of surface enrichments (carbon, chlorine, alkalis, iron) after exposure to atmospheric fluids and moisture. Mn-, and Fe-surface enrichments of analogous glasses of the XIVth century are related to the formation of Mn and Fe oxy/ hydroxides on the surface. The impact on the glass darkening is considered in terms of urban pollution and mass tourism
Y1  - 2005
ER  -