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Noble gas solubility in binary CaO‐SiO 2 System
Author(s) -
Shibata Tomo,
Takahashi Eiichi,
Matsuda JunIchi
Publication year - 1996
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/96gl03012
Subject(s) - solubility , noble gas , bar (unit) , materials science , analytical chemistry (journal) , mineralogy , chemistry , geology , organic chemistry , oceanography
New noble gas solubility measurements in binary CaO‐SiO 2 melts at 1100 bar and 1600 °C are presented. The range of estimated solubilities is He: 8.64–35.8, Ne: 6.54–27.6, Ar: 1.09–8.92, Kr: 0.524–5.67, and Xe: 0.181–2.48 (x 10 −5 cm³STP/g‐bar). The solubility is greater for the lighter noble gases and is a strong function of melt composition; the solubility increases with increasing SiO 2 and decreasing CaO contents. It is generally known that CaO produces non‐bridging oxygen by breaking the SiO 4 network, and thus the correlation between the solubility and SiO 2 content suggests that noble gases dissolve in the SiO 4 network. It is known that the network is formed by limited anionic structure units. In the case of CaO‐SiO 2 melts, most noble gases would be accommodated by two anionic units; chain and three‐dimension structural units. The equilibrium constants of He, Ne, Ar, Kr, and Xe for chain and three‐dimension structure units are 26.9, 19.6, 3.49, 1.71, and 0.613 (× 10 −4 ) and 15.1, 11.3, 4.05, 2.68, and 1.23 (× 10 −3 ), respectively. It is concluded that noble gases dissolve in the three‐dimension structure units more than in the chain units.