ABSTRACT

The isotopic ratios of magnesium in rocks coming from the upper mantle and Bruderheim chondrite were measured by a solid-source mass spectrometer. There is no significant difference in ²⁵Mg/²⁴Mg and ²⁶Mg/²⁴Mg between materials constituting the mantle and Bruderheim chondrite within the limits of 95% confidence. The standard errors of both ²⁵Mg/²⁴Mg and ²⁶Mg/²⁴Mg measurements of a sample were about 0.5%.