Ar isotopes and Earth-atmosphere evolution models

摘要: Earth-atmosphere evolution models are mathematically simulated and the resulting present isotopic ratio (40Ar/36Ar) in mantle is given for each. Differential outgassing experiments on several recent submarine glasses were made to estimate an mantle. Estimations of by various methods also critically reviewed. From experimental results these considerations a minimum value 2000 inferred. By assuming that (40Ar/36Ar)M larger than potassium content 50 ppm, we can limit considerably choice among models, i.e. (1) continuous degassing process not explain rare gas atmosphere, (2) early sudden more likely (3) such must have occurred earlier 4.35 b.y.