By applying both vacuum crushing and stepwise heating methods for the extraction of the noble gases, we have discovered ³He/⁴He ratios much lower than the atmospheric ratio (∼0.3 RA; RA is the atmospheric ³He/⁴He ratio of ...
Isotopic signatures of mantle-derived xenoliths have provided much information on the evolution of their mantle source regions. A recently developed multiple-collector inductively coupled plasma mass spectrometry method ...