Kinetic Isotope Effects in Oxygen in the Laboratory Dehydration of Magnesian Minerals†

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• 作者：Robert N. Clayton* ; Toshiko K. Mayeda^‡ ;
• 刊名：Journal of Physical Chemistry A
• 出版年：2009
• 出版时间：March 12, 2009
• 年：2009
• 卷：113
• 期：10
• 页码：2212-2217
• 全文大小：149K
• 年卷期：v.113,no.10(March 12, 2009)
• ISSN：1520-5215

文摘

Laboratory studies of vacuum dehydration of Mg−O−H units in minerals and rocks reveal large kinetic isotope effects in oxygen, with light-isotope enrichment in the liberated water, and concomitant heavy-isotope enrichment in the residual solids. Application of the same techniques to a meteorite assemblage including hydrous magnesium silicates shows a much more complex behavior, probably due to isotopic heterogeneity inherited from processes on the meteorite parent body. Measurements of both the ¹⁷O/¹⁶O variations and the ¹⁸O/¹⁶O variations confirm theoretical predictions that slopes of three-isotope correlation lines are systematically larger for equilibrium isotope effects than for kinetic isotope effects.